TMB 100mm F/8
ValeryD
"In fact, the TMB 100mm/800mm SD triplet is the best
corrected lens on the market now, from any company."
This is not a fact. Of course this objective is too small
and too slow to be compared with other, more practical
F/# APO triplets.
But I can state and place my reputation as optical designer,
that such cheap combination as any well made 100mm F/10
achromat (say, Sinta one) in combination with Chromacor-II
(when properly collimated in a scope) will beat that 100mm F/8
SD triplet in terms of secondary color correction and will be
completely free of spherochromatism.
If to see on spot diagram, all colors from 420nm to 656nm are
INSIDE Airy disk diameter. This can't be achieved with that
100mm F/8 SD triplet.
OK, this is the case with F/10 achromat. No problem, let take
100mm F/8 and again use a Chromacor-II. Again, color correction
within 420nm to 656nm is better, than in TMB 100mm F/8 SD triplet.
Let take 120mm F/8.3 achromat and Chromacor-II. The same result -
color correction is better, than in TMB 100mm F/8 SD triplet.
Even 150mm F/8 achromat being correctly matched with Chromacor-II
show ZERO color on any object.
Of course, for many such true APO as SD triplet is more attractive
telescope design. But it is not the best in the color correction.
Valery Deryuzhin
ARIES.
Tom Davis
I never saw that level of correction from either the
Chromacor, or the Chromacor II. I tried every spacing,
every possible effort being made to get perfect collimation,
and the 100/800 you refer to clearly outperformed them.
The same is true with the 92mm 700mm FL Burgess
Fluorite. Please don't get into this any further. I have
enough first-hand use with multiple Chromacors that you
sent me that you ust don't want to go down this road.
The Chromacor works, but is a high maintenance item, and
the two scopes in question are not. I don't have to go out
and collimate my scope everytime I use it. I did not have
to collimate the 100/800, and only had to collimate the
92mm fluorite once, and that was because of a prototype
lens cell. It holds collimation perfectly now.
Thanks, Tom Davis
"ValeryD" <ar...@mercury.kherson.ua> wrote in message
news:5c4a4ee7.0411...@posting.google.com...
SweetGus the AssClown
ar...@mercury.kherson.ua (ValeryD) wrote:
Good god......not you again.
Bill Meyers
I can't cfomment on the Chromacor nor on Valery's spot diagrams but I
can give my own experience.
I have used a TMB 100 F/8 belonging to an observing buddy, and I have
posted about it on s.a.a., about a couple of years ago.
I found that it gave beautiful star images, and was amazed to see that
on Vega and other stars the image did not braak down at 600x, and it
remained a perfectly round tight image.
I have heard claims like this about other top quality apos and
felt it was hyperbole by inexperienced observers, and I would not have
believed it until I saw these images. This to my mind is a wonderful
scope. I saw no secondarfy color in focus. I fail to see how those
images could have been improved. I am speaking of images in focus at the
eyepiece. I did not look at out of focus images, nor did I consult spot
diagrams or use an interferometer. I am an observer.
The TMB OTA at that time was heavy, and I felt it was overbult,
but I would not call a four inch 32 inch focal length impractical.
Clear skies,
Bill Meyers
Mark D
Hello Valery, While I don't posess the knowledge that either you, or
Tom Back posesses as a designer, I won't debate the possibility of an
Achromat w/Chromacorr having better color correction than the LZOS made
100mm F-8 Apo Lens, as this might be a possibility.
What is debatable though is to think that any Chinese manufacturer right
now would be figuring a lens as well as LZOS would, a sub-contractor of
Zeiss.
I'm sure Spherochromatism, and Strehl ratios are not the only things
that make a good lens.
On interferometer, I'm quite sure any of the Syntas would show rough
zones in figure, and not anywhere near the P-V specifications as a good
LZOS Lens.
Doesn't lens smoothness, and adhering to proper design parameters
account for anything?
What good is a lens that is perhaps highly corrected for color, when a
sample lens may only exhibit 1/2-1/3 wave figure?
Then, is Chromatic abberation considered to be the only criteria of a
good lens, and lens design? I think you know the answer better than I
do. Mark
Leonard
> >Tom Back wrote:
>
> "In fact, the TMB 100mm/800mm SD triplet is the best
> corrected lens on the market now, from any company."<<<
Come on Val , kicking Tom Back again and again has
got to be getting old even for you . Your own equipment reviewer does
not agree with you.
I know you have better things to do . Most people don't care if Tom
Backs head is so full of himself as to be ready to explode. Most
people only care about if Mr. Back is delivering on what he says he
can . And it seem he can .
So maybe you could :
1- Make some more chromacorrs , there hard to find .
2- You may have a review of your eyepiece the SPL vs. the TMB
mono. coming up on the AP newsgroup. At least its said to be in the
making . What if yours comes out second to the TMB mono. You could
take some time and think about what your going to say .
3- And last but not least , where are all the Aries APO's ?
4- Don't forget all this may bring the " Old Judge " over here
typing a longgggggggg boring disseration about what a bad boy you are
. Please save us from that !!!!!!!!!
Leonard
ValeryD
> Valery,
>
> I never saw that level of correction from either the
> Chromacor, or the Chromacor II.
You didn't used Chromacor-II with 100mm F/10 achromat. F/10 is
much more forgiving for collimation than F/8.
Also, the fact, that you need to collimate Chromacor each time
you use it does not say anything bad about Chromacor itself -
this just indicate how bad can be mechanics in chinese telescopes.
More, Chromacor was not purposed for constant removing from a scope.
I was able to adjust mechanics in my chinese refractors - 100mm F/10,
120mm F/8.3, 150mm F/8 that they never required Chromacor recollimation.
All depends how good mechanics in your scope, how good your skill
and patience are.
You can ask Sol Robbins, who is not an engineer/optician, but he has
enough knoweleges and patience to be able to choose right correction
of Chromacor and to perform it's correct installation and he don't need to
collimate his rig each time. Ask him if he can see any color on selestial
objects. Note, that 100mm F/10 has about 3x less color influence on image.
If he can't see any color in his 150mm F/8 scope, it is worthless to
speak about 100mm F/10 + Chromacor-II.
VD
Tom Davis
If you need to be an engineer to make the Chromacor work,
you've answered your own question. Having no corrector is
better than a corrector that needs to constantly be tweaked.
Yes, the standard Chinese mechanics are an issue, but they
are an issue that needs to be dealt with by anyone using
such a scope with a Chromacor. As you add up the cost
of upgrading a scopes mechanics, it becomes more and more
expensive a proposition. The only answer is to have a
pre-installed, permanent Chromacor, or a lens that does
not need one.
Sort of reminds me of the old Jaguar XKEs. When
everything was right, they were great sports cars. When they
had a problem, you needed a Jaguar specialist to fix one.
Any refractor that needs an expert to keep working, is not
going to fly with most buyers. Until you can get a scope
with a Chromacor III pre-installed, with little user
maintenance required, it is not fair to be bashing Thomas
Back, or anyone else with a working triplet APO or
doublet APO design. I'm very happy that Sol has a great
scope, but that did not happen with my Chromacor II.
I did not have a collimation issue. While the color correction
was far better than the native achromat, I had a slight
turned edge (which the Chromacor II could not fix), and
no matter how I spaced it, I still did not get the level of
color correction that even the pre-TMB 100/800, or the
current 92/700 Burgess Fluorite could provide. The TMB
100/800 is beyond this level, not just in color correction,
but in all other areas of optical correction.
I wish you well with pre-installed Chromacor III equipped
high quality achromats. I think that product could provide
what you discuss to the average buyer. Until then, let's
give poor Thomas a break. He has enough pain with his
neck problem. We don't need to give him any more pain
by bashing products of his that have a proven track record.
Thanks, Tom Davis
"ValeryD" <ar...@mercury.kherson.ua> wrote in message
news:5c4a4ee7.04112...@posting.google.com...
Ted Kord
If Valery spent as much time designing and building scopes as he does attacking
other vendors, he could produce a scope that has zero CA, zero SA, perfectly
smooth surface and polishing.
You know, it's a general axiom that those who put others down do so to
feel better about themselves for their inferiorities.
TMBoptical
>But I can state and place my reputation as optical
>designer, that such cheap combination as any well
>made 100mm F/10 achromat (say, Sinta one) in
>combination with Chromacor-II (when properly
>collimated in a scope) will beat that 100mm F/8
>SD triplet in terms of secondary color correction and
>will be completely free of spherochromatism.
>If to see on spot diagram, all colors from 420nm to
>656nm are INSIDE Airy disk diameter. This can't be
>achieved with that 100mm F/8 SD triplet.
Wrong again Val. I really don't know why I am wasting
my time with you, and you can be sure I won't again,
but when you said you would place your reputation as
an optical designer on the line, well, I had to respond.
Yes it can, and the TMB 100 f/8 has all the wavelengths
inside the Airy disk diameter from less than 420nm
to 706nm, beyond your Chromacor-II performance,
which is never truly achieved in the real world, only
on your Zemax screen, as Tom Davis so well pointed
out.
I will be posting the spot diagram of the TMB 100mm
f/8 on the TMB Yahoo Group, if anyone is interested.
And for the people that think my head is too big, that's
fine, but I do speak the truth, and if that gives me a
big head, so be it. There was a better corrected lens
at one time than the TMB 100mm f/8, the Zeiss 100mm
f/10 APQ. But that scope has not been for sale for
many, many years.
Happy Thanksgiving s.a.a.ers!
Thomas Back
TMB Optical
ValeryD
> Come on Val , kicking Tom Back again and again has
> got to be getting old even for you . Your own equipment reviewer does
> not agree with you.
> I know you have better things to do . Most people don't care if Tom
> Backs head is so full of himself as to be ready to explode. Most
> people only care about if Mr. Back is delivering on what he says he
> can . And it seem he can .
You are mistaken. Markus can. Markus. Period. Markus has a contract
with LZOS. Tom designed these triplets after I refused to do this
job for Markus when he asked me.
I can agree, that this theme is getting old. But you do not looking in the
root. In the root you will see, that TMB constantly claims, that "his"
apos are best of the best on the market.
This is not true at all. They one of the best - yes. But not the best.
Many peoples out here should remember falsification about others products
at TMB Yahoo group. Even cooked illustration were used to prove these
statements, that so called TMB apos are best in the world.
I can assure you, that the design of these LZOS apos ( TK12-OK4-K8)
can't match performance of other designs, especially fluorite triplets.
Indeed, this or similar combinations (in LZOS objectives) is quite good,
but not the best and 100mm F/8 objective has better color correction, than
other objectives ONLY because it is small and has slower F/D. No another
reasons.
I can assure you, that if you will call to Parallax Instruments (to the owner)
and ask him about image quality (include color correction) of ARIES 127mm F/7
Fluorite triplet with RMS 0.012, he will tell you something. I hope, that this
scope was not re-sold. Same with other our 127mm F/7 triplets, they, however,
have somewhat less perfect figures - but most of them better, than RMS 0.025.
So, you'd better advise Tom Back be more modest and not claim, that products
he sells are best of the best.
>
> So maybe you could :
>
> 1- Make some more chromacorrs , there hard to find .
We will. Wait a bit more. They will be of better quality than before
and.... wait our principally new solution of color correction in achromats
and our new middle-level affordable APOs.
>
> 2- You may have a review of your eyepiece the SPL vs. the TMB
> mono. coming up on the AP newsgroup. At least its said to be in the
> making . What if yours comes out second to the TMB mono. You could
> take some time and think about what your going to say .
No. I will think what need to do improving the optics!
>
> 3- And last but not least , where are all the Aries APO's ?
Due to "help" of one well known person, closely associated with these
objectives in question, we stopped their manufacturing for a while.
But this year we resumed their manufacturing at our own labs. Right
now several 7" F/7.7 doublets are waiting tubes for them.
Then we will continue with several new models doublets and triplets.
It is easy to begin, when you have a large optical plant behind you.
Much more difficult if you try to do this in house, in your own labs.
This need a time and significant money investment.
But once this will be done, we can control all in the process and play
with prices as we wish - to make our product more competitive and more
attractive for buyers.
And, if you wish, drop me a letter and place an order for 7" Fluorite
doublet. You will be impressed with it's color correction, image contrast
and sharpness and will note how short it's cooldown time.
> 4- Don't forget all this may bring the " Old Judge " over here
> typing a longgggggggg boring disseration about what a bad boy you are
> . Please save us from that !!!!!!!!!
He will ends badly, IMO. ;>)
VD
Leonard
>
> I will be posting the spot diagram of the TMB 100mm
> f/8 on the TMB Yahoo Group, if anyone is interested.
Thanks , will look for it .
>
> And for the people that think my head is too big, that's
> fine, but I do speak the truth, and if that gives me a
> big head, so be it. There was a better corrected lens
> at one time than the TMB 100mm f/8, the Zeiss 100mm
> f/10 APQ. But that scope has not been for sale for
> many, many years.
Valery wrote :
<<< Dear Mr. Back,
Sure, your self-confidence has no limits. And as one, well known
in optical design and manufacturing, person said, someday your head
will explode due to your unlimited self-confidence.>>>>>>
>
> Happy Thanksgiving s.a.a.ers!
>
> Thomas Back
> TMB Optical
Thanks , And a happy Thanksgiving to you and yours .
Leonard
ValeryD
> If Valery spent as much time designing and building scopes as he does >attacking
> other vendors, he could produce a scope that has zero CA, zero SA, perfectly
> smooth surface and polishing.
It is not attacking! You, perhaps, has no clue what is what.
Constantly saying, that ONLY HIS PRODUCTS are the best is an
indirect attacking of others.
And I never said, that these TMB objectives are any bad in any
aspect, they, in fact are very good, just not as good as Tom Back
constantly saying.
And I can assure you, that the optics we making is one of the best
available. I can's say best, because I don't know exactly what
other manufacturers are capable for at their limits.
If, for example, these objectives are small, all _spherical_ and
have warranted only 0.033 RMS, our optics with huge aspherics, much
larger in diameter and can be ordered and made with precision of 0.02
RMS and better, then your phrase "If Valery spent as much time
designing
and building scopes as he does attacking other vendors, he could
produce a scope" looks just soap bubble, nothing more.
I can add, that so called best of the best objectives, say, 6" F/8,
being
TRIPLETS has same longitudinal color aberration (within 430nm-656nm),
as our 7" F/7.7 _doublets_ . And they have worser aberration if we
will jump to
175mm F/8 vs our 7" F/7.7.
I took their longitudinal color aberration from original source.
And wait a bit longer. Soon several firms (at least three) will come
with their own fluorite and SD scopes of the same slow F/D, as these
TMB objectives, they will be also air-spaced, but cheaper. Then you
will see if one amateur user of Zemax can create a miracle or not.
For you instance - designing of APO triplet is 10min job. Maximum.
So, I don't need to much time for this.
VD
ValeryD
> Wrong again Val. I really don't know why I am wasting
> my time with you, and you can be sure I won't again,
> but when you said you would place your reputation as
> an optical designer on the line, well, I had to respond.
>
> Yes it can, and the TMB 100 f/8 has all the wavelengths
> inside the Airy disk diameter from less than 420nm
> to 706nm, beyond your Chromacor-II performance,
> which is never truly achieved in the real world, only
> on your Zemax screen, as Tom Davis so well pointed
> out.
>
> I will be posting the spot diagram of the TMB 100mm
> f/8 on the TMB Yahoo Group, if anyone is interested.
Tom,
I think you will not loss anything wasting your time here.
And I know what the glasses do you use in these objectives.
Due to inherent spherochromatism, it is impossible to accomplish
the design, where all colors even from shorter range, than you
pointed out, will have all spots within Airy disk (for each color
it's size is different).
Without significant space (between lenses) increasing, spherochromatism
can't be fixed and it will be the reaason, that all spots will not
be within Airy disk.
This is not well known for public, but spherochromatism also
influent on image contrast and even if an eye can't see colors,
image still have some softness.
I can't say, that Chromacor-II with 100mm F/10 achromat is better
combination from practical point of view than 100mm F/8 SD triplet.
Not. Triplet has much larger useful field for photography and does
not require any collimation (if it's mechanics is properly made).
Chr-II + 100mm F/10 achromat has smaller field - lateral color and
vignetting limit it. But for visual applications, especially at high
powers, this is not a problem at all.
And this combination has completely fixed, spherochromatism and
all colors within 430nm - 656nm are WELL inside Airy disk. This
can't be accomplished with such fast triplet as 100mm F/8 is.
As for correspondance between what Chromacor shows on Zemax screen
and practice, then I can say one thing - all depends of who do use
a Chromacor. Even such experienced practical observer as Ed Ting was
mistaken in his proper use even if instructions at my Yahoo group
was detailed enough.
Also, there is no warranties, that chineses keep their objectives
very consistent in color correction, because they do not re-touched
the design according to meltings. But this variations are indeed small.
As for Chromacor itself. Glasses refractive indexes always measured with
about 2x10-6 precision. Not worser. This is absolutely enough to keep
Chromacor's practical realization exactly as at the Zemax screen.
I don't know how many of Chr-II users were able to collimate it
properly, but thouse, who were able to perform this relatively simple
job, reported, that they can't see any color on any object - just the
same as through any another 6" F/8 triplet. If Tom Davis was not able
to achieve such performance for whatever reason, this does not necessary
mean, that his experience is absolute.
And, of course, 100mm F/10 achromat is MUCH MUCH more forgiving for
Chromacor collimation and color correction here is about 3+ times
easier to reach, than in 6" F/8. If properly installed and collimated
Chr-II shows no colors in 6" F/8, then it is worthless to say what
the correction will be in 100mm F/10.
From the other side, I can say, that triplets in your design also
quite sensitive for glasses refractive indexes deviations and they
also require redesign according to glass melt data - and they have
the same source of errors. Period. Only idiot can argue with this.
VD
Mileva Maric
where of course all scope outside of the lab must perform.
These theoretical discussions always dismiss that. Im glad you
bring it and all readers back to the real world.
When the Chromacor first came out and for two years we were
beated raw by the cheerleaders/commercialists-vested and
other 'experts' regarding this 'mirabulus fidelus'. Then the matter
if spacing came up and there was consternation, back peddling,
then forward sprinting to new levels of ritual.
So the following question seems appropriate: "If I mated a
TMB 100 f/8 to the proper Chromacor could I achieve
5x10^6 magnification and still colour free, in time for Christmas
at WalMart? (hee
hee)
Have a very nice day, and thank you for your sanity.
Mark
Mileva Maric
ValeryD wrote:
> ngc...@citynet.net (Leonard) wrote in message news:<58ee67ec.04112...@posting.google.com>...
>
> So, you'd better advise Tom Back be more modest and not claim, that products he sells are best of the
> best.
He never said that. He never says that. That's your job!
Mark
Tom Davis
> to achieve such performance for whatever reason, this does not necessary
> mean, that his experience is absolute.
> And, of course, 100mm F/10 achromat is MUCH MUCH more forgiving for
> Chromacor collimation and color correction here is about 3+ times
> easier to reach, than in 6" F/8. If properly installed and collimated
> Chr-II shows no colors in 6" F/8, then it is worthless to say what
> the correction will be in 100mm F/10.
>
> From the other side, I can say, that triplets in your design also
> quite sensitive for glasses refractive indexes deviations and they
> also require redesign according to glass melt data - and they have
> the same source of errors. Period. Only idiot can argue with this.
>
>
> VD
Valery,
I think what is a common thread here is that both you and Thomas are
dependant on other's work to make your designs successful. In the
case of the Chromacor, the telescope it is used on will determine how
well it will work. In that case, the optics much be smooth, and free from
zonal errors. The match of the spherical abberation in the telescope it
is used upon must match the degree of opposing correction (or lack of
it) must be matched in the Chromacor used. The mechanics (the focuser
used) must be able ot be collimated, and hold that collimation. This is
why early on I recommended the need for properly built achromats with
a pre-installed Chromacor for this product to properly work. One
issue that became clear as crystal was that when color errors were
resolved by the use of this device, other errors became more readily
observed. Unless those errors could be addressed, this product could
not be successful. Sometimes a sow's ear just can't be converted into
a silk purse. I found this to be the case with a more than half of the
scopes I tried the Chromacor on. Either mechanical issues, improper
matching, or optical issues such as zonal errors or turned edge prevented
the final result from matching the performance that individuals such as
Sol Robbins experienced. If you finally do provide your own achromats
with a newer version of this device with better control of edge of field
correction (I gather from past discussion the Chromacor III will do this),
pre-installed at a factory where you control quality issues, then this
product may reliably work. I ran proof of concept testing early on.
I had a couple of scopes that worked with the early device, but the
weak link was cheap mechanics, and what optical issues did exist in the
scopes involved. The Synta 6" F/8 scopes were the most consistent in
quality, better than the 120mm F/8.3 versions I owned, but still not as
consistent as the LZOS production of the TMB designed lenses by a
longshot.
I think if we took a pole of who was more satisfied with the resulting
product, we would find the TMB 100/800 buyers would readily say they
were over any Chromacor buyers. Common sense dictates that there are
fewer weak links in the LZOS built TMB lenses, with fewer variables,
than trying to apply an aftermarket device to lower cost optics and
mechanics. Really, control over all the needed variables is much
simpler if everything is controlled by one manufacturer, as has been by
Thomas and Markus in the production of the TMB scopes. Until you
have control of the finished telescope, I really don't see how a valid
comparison may be made. Consistency of results favor the TMB/APM
product. It is up to you to change that by producing a total package,
either by Aries directly, or in partnership with vendors that you have
control of the process with.
What needs to be understood is that the buyer generally does not care
whose label is on their telescope, or even who makes it for that matter.
Squables about designs and their relative merits mean little if the actual
product does not perform to the level that the buyer expects. A fair
design well executed in the final production product will generally be
preferred over a poorly executed excellent design in the final product.
Without control over any potential weak links in what your Chromacor
is used in, success rates will be fair at best. Sol Robbins had the right
scope and Chromacor match, others of us did not. I have no doubt I
could have gotten Sol's scope to work, but I did not have it. If the blame
becomes the customer's, the old saying that "the customer is always right"
comes into play. They will reject the product, and buy what works. They
really don't care that a product would work if they did "X Y and Z". They
may not want to, or now how to do the needed steps, or those steps may
not work on their equipment. I know about Ed Ting's experience, where
he was told to use a 48mm spacer, and the meaning of the term was
misunderstood (what was meant was a 4mm long 48mm DIAMETER
spacer, not a 48mm LONG spacer), but many experienced partial
success that did not meet their expectation when they properly followed
instructions (the equipment had poor mechanics, their optics had issues,
the Chromacor/objective match was less than ideal). Again, you need
to provide a turnkey product. If you do that, you won't need to worry
about TMB does. Customers want to buy turnkey solutions, where they
know it will work right out the box. That is my recommendation. While
we may be interested in how something is designed, whether it will work
for us as advertised, at a price we can afford, matters most to us..
Thanks, Tom Davis
Chris.B
>
> I don't know how many of Chr-II users were able to collimate it
> properly, but those, who were able to perform this relatively simple
> job, reported, that they can't see any color on any object - just the
> same as through any another 6" F/8 triplet. If Tom Davis was not able
> to achieve such performance for whatever reason, this does not necessary
> mean, that his experience is absolute.
> VD
Nobody has answered the question of inherent optical surface roughness
affecting the Chinese achromat. Does the spherical aberration
reduction of undercorrected achromat + Chromacor 01 affect the
smoothness issue for visual and small field lunar/planetary
photography? I'm thinking in particular of the typical slightly
undercorrected 6" f/8 Synta achromat in combination with an 01
Chromacor. Producing a (claimed) therorectical 1/42 wave spherical
correction. Is the (supposed) surface roughness also reduced by the
Chromacor? Or is this just wishful thinking? :-)
Thanks
Chris.B
Ted Kord
to your superiority. You make the best telescopes ever, and the best that will
ever be made. You are all knowing.
By the way, Tom Davis wasn't saying that Chromacor wasn't good, just not as
good as you say...Now why does that sound familiar?
Markus Ludes
> From the other side, I can say, that triplets in your design also
> quite sensitive for glasses refractive indexes deviations and they
> also require redesign according to glass melt data - and they have
> the same source of errors. Period. Only idiot can argue with this.
>
>
> VD
Valery,
reply only to above. That what you say here is correct , but it is also
done by LZOS, you know this people are not stupid. Each lens is
foritself a single Masterpiece
Markus
--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG
Chuck
hats off to you and Astro-Physics Valery...
"ValeryD" <ar...@mercury.kherson.ua> wrote in message
news:5c4a4ee7.04112...@posting.google.com...
Tom Davis
"Ted Kord" <ted...@excite.com> wrote in message
news:7c0be594.0411...@posting.google.com...
Ted,
Exactly my point. Sol Robbins has a fine setup with the Chromacor II
and a good CR150 to use it with. My point was that the Chromacor is
only as good, or bad as the intrument it is used in, and also that it has
maintenance issues related to the use of it that make a high quality APO
preferable to it, price independant. Also, while I found the improvement
in color correction to be significant, I did not near the level of
correction
found in a TMB 100/800 when using it in a 120mm F/8.3 Konus with
ideal spacing. Also, I tried to make clear that even with the spherical
correction feature, other optical issues inherent in the general run of
Chinese achromats prevents the theoretical capabilities of the device
from being attained in most real-world use situations. It was not intended
to belittle what Valery accomplished here, but rather to show that a
scope designed as a complete package would be preferable, price
independent. I believe Valery has discussed developing such a complete
package, and at that point such a comparison could be made, and the
results would be valid.
Thanks, Tom Davis
ValeryD
Can you read? If yes, please:
"
<snip>
In fact, the TMB 100mm/800mm SD triplet is the best
corrected lens on the market now, from any company.
<snip>
Thomas M. Back
"
ValeryD
> >
> > From the other side, I can say, that triplets in your design also
> > quite sensitive for glasses refractive indexes deviations and they
> > also require redesign according to glass melt data - and they have
> > the same source of errors. Period. Only idiot can argue with this.
> >
> >
> > VD
>
> Valery,
>
> reply only to above. That what you say here is correct , but it is also
> done by LZOS, you know this people are not stupid. Each lens is
> foritself a single Masterpiece
>
> Markus
Yes. No questions at all. But give us a credit too! We can measure
glasses constants with 2x10-6 precision and in some cases, when this
really needed with 1x10-6 precision, so we can warranty, that Chromacors,
if properly installed work exactly as designed and if any deviation from
designed parameters, this has nothing to do with Chromacors, but with
objectives parameters deviations.
VD
Ed T
"Chuck" <cscapp...@adelphia.net> wrote in message
news:aOudnYmmg5j...@adelphia.com...
> Off topic, but I have bought two AP SPL eyepieces, they are exquisite,
> hats off to you and Astro-Physics Valery...
Yes, they are superb. I need my four millimeter. Valery?
Ed T.
TMBoptical
>products he sells are best of the
>> > best.
>>
>> He never said that. He never says that. That's your job!
>> Mark
>
>Can you read? If yes, please:
>
>"
><snip>
>In fact, the TMB 100mm/800mm SD triplet is the best
>corrected lens on the market now, from any company.
><snip>
>Thomas M. Back
Of any current apochromatic telescope that is currently
on the market (not a telescope with any type of add
on color correcting device (which I only say because
I cannot know how well corrected such a telescope
will be), the TMB 100mm f/8 is the best optically
corrected lens on the market, in the meaning of the
best color correction, and lowest wide band RMS
values. We are talking absolute performance, not
a rare lens that has a peak wavefront from hand
figuring that is super high. That is a different thing
altogether, and in the case of the TMB 100mm
f/8, we have reached Strehl ratios of .995 to .997
in the green, as tested by interferometry, which
is pushing the limits set by the glass itself.
If it is not, please, anyone out there, Roland, Valery,
Markus, whomever, tell me a lens that is better
corrected (remember, it has to be a lens that is
available from stock, not some custom one-off lens),
and I will stand corrected.
Thomas Back
ValeryD
They are the most difficult to make. Their lense like a rise particle -
very difficult to handle and work with. Their surfaces are steeep - can
be made one by one only.
We made a serie of first design and were need to redesign and make
them again. They will be available last from all the SPL because we
were need to start them when other were in progress.
f3.3 will be available even later and will be more expensive.
VD
ValeryD
Tom,
I agree with ALL what you said here. But I need to underline again -
this
was not a sense of my initial post. I just wrote, that 100mm F/10
classical
achromat ( with C-F correction) being used with Chromacor-II and
properly
installed (SA match does not really needed for this) will deliever a
color correction, which can't be matched by ANY traditional (with
small
air spacing) triplets - be they SD from TMB or SuperED or even
fluorite.
The main reason - such design (Chr-II + achromat) has no
spherochromatism
and color correction is about 60x better vs traditional achromat.
This design 4 crossings. But the graph of focus variation for
different wave lenghths looks almost flat unlike to traditional apos.
Diameters of spot circles for each wave length are well within Airy
disk
(for each wave length diameter of Airy disk is different).
I can't argue with the statement, that APO with triplet objectives
have
fewer (if any) problems for proper collimation vs achromat+Chromacor,
but customers, who were able to make Chromacor work as advertised, are
satisfied too - they have apo performance for MUCH less money! Many of
them just have no money to buy a true APO.
I hope, that now you do understand what did I meant speaking about
color correction.
VD
ValeryD
> Nobody has answered the question of inherent optical surface roughness
> affecting the Chinese achromat. Does the spherical aberration
> reduction of undercorrected achromat + Chromacor 01 affect the
> smoothness issue for visual and small field lunar/planetary
> photography? I'm thinking in particular of the typical slightly
> undercorrected 6" f/8 Synta achromat in combination with an 01
> Chromacor. Producing a (claimed) therorectical 1/42 wave spherical
> correction. Is the (supposed) surface roughness also reduced by the
> Chromacor? Or is this just wishful thinking? :-)
>
> Thanks
> Chris.B
Chris,
Chromacor does the following:
1. Corrects secondary spectrum of achromat.
2. Corrects spherochromatism (spherical aberration dependance of wave
length)
3. If necessary, spherical aberration of 3-rd order.
No another aberration can be corrected, include surface errors (zones,
turned edge and roughness).
I can't comment about all objectives, but five ones I do own, have very
good smoothness, while spherical aberration is vary from about 1/3 wave
to 1/8 wave.
As for spherical correction. It can be even nullyfied down to zero.
Valery Deryuzhin
max
> Tom Back wrote:
>
> "In fact, the TMB 100mm/800mm SD triplet is the best
> corrected lens on the market now, from any company."
>
> and too slow to be compared with other, more practical
> F/# APO triplets.
>
> that such cheap combination as any well made 100mm F/10
> achromat (say, Sinta one) in combination with Chromacor-II
> (when properly collimated in a scope) will beat that 100mm F/8
> SD triplet in terms of secondary color correction and will be
> completely free of spherochromatism.
> If to see on spot diagram, all colors from 420nm to 656nm are
> INSIDE Airy disk diameter. This can't be achieved with that
> 100mm F/8 SD triplet.
>
> 100mm F/8 and again use a Chromacor-II. Again, color correction
> within 420nm to 656nm is better, than in TMB 100mm F/8 SD triplet.
>
> Let take 120mm F/8.3 achromat and Chromacor-II. The same result -
> color correction is better, than in TMB 100mm F/8 SD triplet.
>
> Even 150mm F/8 achromat being correctly matched with Chromacor-II
> show ZERO color on any object.
>
> Of course, for many such true APO as SD triplet is more attractive
> telescope design. But it is not the best in the color correction.
>
>
> Valery Deryuzhin
> ARIES.
I hate to post on such a thread. However, I beleive there are some out
there who want to jump into the hobby with their first scope and they
deserve better.
A long story short: My first turn off from astronomy was a department
store scope. Among many other problems, when I finally pointed at
something any movement whatsoever would make me lose it.
Then the ETX. Heck, just assemble turn switch on and tell the coputer
what you want to see. I spent so much money on software and gadgets
that if posted, it would fall in the incredible.
Finally, I did some homework, learnt a little about scope design,
aperture/performance, learnt my way around the sky and threw away all
the worthless gadgets. I now love my ETX for what it is, no more no
less.
I later upgraded to larger apertures and several premium refractors.
They are what they are. Each of my scopes serves a purpose and it
serves it well as it is.
I can not think of anything worse to turn an amateur astronomer from
astronomy than an expensive gadget to tweek a cheap scope that in
itself needs tweeking. Moreover, these favulous claims of its
performance are beyond my comprehension. What I understand from this
thread is that if you buy this wonder product and put it on a cheap
refractor it will perform better than a TMB 100/8. Hey, if it does
not, the user must be an idiot for not beeing able to set the gadget
up properly. What a major put down.
I have a TMB 100/8. I care not for the lambdas, strhls, wavefronts,
spotdiagrams.... I do however care that at least visually, it has cero
false color in or out of focus (for whatever purpose you would want to
test this out of focus). You can equal that but I know not how you can
better it.
My CCD show textbook color patterns. But even this does not mean
anything to me as an observer. With so much image processing what are
true colors? This reminds me of an article some time ago about the
Universe's TRUE color, it turns out they made a mistake. OOPS.
My experience for what it is worth is that you get what you pay for. A
cheap Chineese/Japanese/French/.... refractor is precisely that a
cheap Chineese/Japanese/French/.... refractor. A premium refractor is
a premium refractor. I would recommend anyone to know what it is they
are buying before buying so as not to get false hopes. Regarding this
thread, I would recommend anyone thinking on buying a cheap refractor
to evaluate other optical designs enstead. In my personal opinion,
cheap refractors only serve to sway interested amateur wannabes away
from the hobby.
MAX
RichA
wrote:
What would it have cost to sell an achromat/chromacor
package that:
1. Provided an achromat that did not suffer from some of the problems
and irregularities the Chinese units do. Say a 120mm f8 as the achro?
2. Was housed in a tube assembly that allowed the chromacor to be
used on the diagonal with no collimation issues? Something permanent
so they could just put it on the scope and use it?
Now, currently, you need a:
Chromacor $750 or so.
Scope $300 (Synta 120mm f8 OTA).
A diagonal $125-$200
Some kind of aligner for the Chromacor $50?
But how much would it cost for scope with an integrated Chromacor that
wouldn't need alignment?
TeleVue have long used that sub-diameter reducer/corrector in their
tubes to achieve fast focal ratios and it's selling point is that
it's fixed in place, no fuss.
My guess is you'd need a tested achromat, a better tube and focuser
and some way to integrate the Chromacor so it's permanently housed
inside the scope. So maybe a Vixen lens, the Chromacor, tube,
diagonal, chromacor mounting, focuser.
Say $2000-$2500 as a guess? Still way below the cost of a 4.7"-5"
apo from any of the manufacturers.
-Rich
-Rich
RichA
So the only thing propelling the hobby ahead are $3500+ apos
and not the thousands of 4-6" Chinese achros that have been
sold? Sorry, I don't buy that for a second.
But I agree, you get what you pay for.
-Rich
rumpledoll
by a competent designer. My 4" scope is an AP Traveler (105 f/5.8), but
it would be hard for the design of that scope, or the TMB 105 f/6.2 to
match the correction of the 100 f/8. The Traveler and, I presume, the
TMB 105 f/6.2 have other virtues that the 100 f/8 doesn't have.
The only telescope that I remember that *might* match the correction of
teh TMB 100 f/8 would be the long discontinued 130mm f/12 APO MAX, but I
don't have the skill to perform any such analysis.
TMBoptical wrote:
>...the TMB 100mm f/8 is the best optically
Leonard
Hello Valery ,
Its a shame this innovative instrument (
chromacor)
is used and seems to be made for Synta achromats that have less than
excellent
quality control . This does not show your chromacor in its best light
.
Please find someone who makes fine high quality
achromats with excellent machanics and form a partnership , I feel the
market would gladly accept and buy such a product .
D&G optical maybe ?
Please keep the quality level of your new eyepiece second to
none !
Leonard
Mark D
by a competent designer. My 4" scope is an AP Traveler (105 f/5.8), but
it would be hard for the design of that scope, or the TMB 105 f/6.2 to
match the correction of the 100 f/8. The Traveler and, I presume, the
TMB 105 f/6.2 have other virtues that the 100 f/8 doesn't have.
The only telescope that I remember that *might* match the correction of
teh TMB 100 f/8 would be the long discontinued 130mm f/12 APO MAX, but I
don't have the skill to perform any such analysis.
Hi, I think I understand what you are trying to say/claim in your above
statement, that you're trying to assume that any given Apo refractor
design, due to having a longer FL will naturally have a better color
corrected lens, correct?
Due to variants in optical design, materials used, this is not always
going to be the case, so I feel this is misleading trying to convince
others that this is indeed true. Mark
rumpledoll
length, the lower the optical aberrations of all types. For sure a
different design can lead to different outcomes, and it takes someone
very skilled such as Thomas or Roland to come up with an optimized design.
I agree that one can't just say, for instance, that A's APO is better
corrected than B's APO simply because it has a longer focal ratio. But
a point to consider is that a designer as skilled as Thomas, working
with an f/8 100mm telescope can kick some tushy, correction wise. He
also kicks tushy with his 105mm f/6.2, and that scope is much more to my
liking in the 4" or so APO range. If I didn't already have a Traveler,
I would get the TMB 105 (Conversely if I had a TMB 105, I wouldn't get a
Traveler).
I have never looked through an APO MAX, but reports say it is a well
executed telescope. One certainly should expected than an f/12 130mm
APO triplet be excellent! The scope is no longer in production, I would
have no doubt that the 100 f/8 TMB is the current correction champ.
CHASLX200
>From: rumpledoll hid...@no.way.com
>Date: 11/26/2004 11:02 AM Eastern Standard Time
>Message-id: <58e45$41a7538f$4503c6a5$20...@msgid.meganewsservers.com>
>
>I think we are inagreement: for a given design, the longer the focal
>length, the lower the optical aberrations of all types. For sure a
>different design can lead to different outcomes, and it takes someone
>very skilled such as Thomas or Roland to come up with an optimized design.
>
>I agree that one can't just say, for instance, that A's APO is better
>corrected than B's APO simply because it has a longer focal ratio. But
>a point to consider is that a designer as skilled as Thomas, working
>with an f/8 100mm telescope can kick some tushy, correction wise. He
>also kicks tushy with his 105mm f/6.2, and that scope is much more to my
>liking in the 4" or so APO range. If I didn't already have a Traveler,
>I would get the TMB 105 (Conversely if I had a TMB 105, I wouldn't get a
>Traveler).
>
>I have never looked through an APO MAX, but reports say it is a well
>executed telescope. One certainly should expected than an f/12 130mm
>APO triplet be excellent! The scope is no longer in production, I would
>have no doubt that the 100 f/8 TMB is the current correction champ.
>
>
>Mark D wrote:
I will say the best image of the sun i ever saw was in a older TMB 100 F/8, it
sure beat my Tak FS-102! I never got a chance to try the TMB on the stars, but
i'm sure it would have been a killer...
Chas P.
Markus Ludes
I have a new apo now which surpass the colorcorrection offered by your
chromacorr matched with 100/1000 achromat by the factor 15 times,
dont believe ? Lets make a bet.
You show me your matched system and I bring my new apo, then we check
side by side , a, by visuel testing, b, by serious company testing,
okay ?
when we can do this comparation, tell me and anybody here time and
date , please !
You cannot accept my bet ? why not ? No chromacorr available at moment ?
when we can see it ? I mean a real time answere is what I wait for, not
a estimation,
since your estimations failing always, due coming up new reasons once
and a while.
See,
early this year you offered me Rnchigratings, Safix for Refractor, Safix
for SC, Chromacorr , my delayed 7" lens.
You posted here that I introducing it with Anacortes. We started a
little and got orders , but the orders got cancled ,
because any promissed delivery time failed, again and again and again.
5 month ago you told me I cna get 2~ 4 pre installed chromacorrs, but
you need permission for export. Status of 2 weeks ago
no shipment till next year spring, your people are to buy with rolly
royce optics for more important customers/dealers.
7" Aries douplet is here promited by you longer since 2 years, but not
yet you have shipped one to somebody who is
known by anybody else on this planet.
So, my apo is same magic as your Chromacorr/achro combo, Nobody can
approve your words and you cannot aprove my words, correct ?
best decision which can be done due this : we shall stop talking about a
computersimulated product which is not on the market
Markus from Germany, who is still waiting your info if you ship me now
the 7" Aries apo as final payment for my deposits from the year 1995 ,
next 10 year my deposit to have you have its 10th year aniversary
happy thanksgiving
Markus
> Tom,
>
> I agree with ALL what you said here. But I need to underline again -
> this
> was not a sense of my initial post. I just wrote, that 100mm F/10
> classical
> achromat ( with C-F correction) being used with Chromacor-II and
> properly
> installed (SA match does not really needed for this) will deliever a
> color correction, which can't be matched by ANY traditional (with
> small
> air spacing) triplets - be they SD from TMB or SuperED or even
> fluorite.
> VD
Markus Ludes
> > Markus
>
> Yes. No questions at all. But give us a credit too! We can measure
> glasses constants with 2x10-6 precision and in some cases, when this
> really needed with 1x10-6 precision, so we can warranty, that Chromacors,
> if properly installed work exactly as designed and if any deviation from
> designed parameters, this has nothing to do with Chromacors, but with
> objectives parameters deviations.
>
> VD
see what you write above : all objectives you have in mind to be used
with your chromacorr
have such parameter deviations, so you must make your own achromats to
match them with
chromacorr to have no such deviations. I know , you will answere me now,
yes excactly that we will doing,
fine, but the questions any customer will adresse to you are :
How much such combo will cost shipped to him include tax ?
What is a real wait time ?
What is doing afterwards support for the combo ?
can you answere this 3 questions to your customers who want your combo ?
best wishes
Markus Ludes
> ***************************************
> I will say the best image of the sun i ever saw was in a older TMB 100 F/8, it
> sure beat my Tak FS-102! I never got a chance to try the TMB on the stars, but
> i'm sure it would have been a killer...
>
> Chas P.
Hi Chas ,
you want a TMB 100/800 ? I got yesterday 9 pc, can sell to from stock,
$ 2,990 incl. shipping for OTA with rings
do we have a deal ?
:-)
CHASLX200
>Date: 11/26/2004 12:36 PM Eastern Standard Time
>Message-id: <e9706ccee37e3da21ff...@mygate.mailgate.org>
>
>
>Hi Chas ,
>
>you want a TMB 100/800 ? I got yesterday 9 pc, can sell to from stock,
> $ 2,990 incl. shipping for OTA with rings
>
>do we have a deal ?
>
>:-)
>Markus
**********************************
I'm still in a Dob mood Markus, once i try out another dozen Dobs or so, then
maybe my mood will turn to APO's.
But i'm thinking a TMB will be my next APO!!!
Chas P.
Mark D
length, the lower the optical aberrations of all types. For sure a
different design can lead to different outcomes, and it takes someone
very skilled such as Thomas or Roland to come up with an optimized
design.
I agree that one can't just say, for instance, that A's APO is better
corrected than B's APO simply because it has a longer focal ratio. But a
point to consider is that a designer as skilled as Thomas, working with
an f/8 100mm telescope can kick some tushy, correction wise. He also
kicks tushy with his 105mm f/6.2, and that scope is much more to my
liking in the 4" or so APO range. If I didn't already have a Traveler, I
would get the TMB 105 (Conversely if I had a TMB 105, I wouldn't get a
Traveler).
I have never looked through an APO MAX, but reports say it is a well
executed telescope. One certainly should expected than an f/12 130mm APO
triplet be excellent! The scope is no longer in production, I would have
no doubt that the 100 f/8 TMB is the current correction champ.
Yes, I won't debate, or question Thomas Backs's, or Roland's, or LZOS
skills with you, as I personally know Thomas, and Roland and both men
are good friends of mine. Neither will I debate what your saying that
yes, longer FL Apos are generally easier for a manufacturer to produce,
with a more gentler suface Radii, and generally doen't have to resort to
using Aspheres in the design.
While Thomas/Roland/Valery/Whomever can design a lens, and all may look
just great on ZEMAX/etc, this doesn't neccesarily mean that this design
will meet these same parameters of said design in the real world.
Lots of little obstacles occur along the way with glass melt data, and
unseen qualities/characteristics.
I think the final outcome can only be truly known when the finished
product is in one's hands, and can then be further examined/tested. It
depends too in what wavelengths a lens is nulled in.
Strehl Ratio can be extremely high in UV, or IR wavelengths, in which
may be superb for a lens specifically designed in an imaging
requirement, either CCD of emulsion photography, yet may suffer, with
considerably lower strehl ratios in the visual wavelengths, and may not
then appear to be so well chromatically correctly for viusual use.
I'm certainly not versed well enough to debate optical designs/strehl
ratios, and hidden problems in optical designs with folks like Roland,
Tom, Valery, or Fred M., maker of the Apomax, but I think I have the
basic idea correct here.
It's just all that easy to say that "X" scope will kick "Y"s scope's
tushy.
The human eye is quite a sensitive instrument, and can detect very minor
anomalies when one knows what to look for, but as Roland has said on
occasion, the Interferometer "Takes no Prisoners".
Yes, the Apomax is a superb scope, with a very nicely made, ultra smooth
figured lens, and both Tom Back, and Markus Ludes also will attest to
this as Thomas Back has personally looked through my own Apomax, admired
the performance, and Markus has owned 2, or 3 Apomax refractors himself
over the last few years, and had praise for the design, and the maker.
Yet, Fred did not personally design the Apomax Lens, it was Dr Dick
Buchroeder who did, and essentially after the run of lenses were
virtually completed, Fred did himself notice a slight design deficiency
in the Apomax Lens which was not at first anticipated, and he personally
stated that at that point/stage in the manufacture, it was too late to
change, or modify the design.
While the lens has a true 4 crossings met in the design, I assume/gather
from Fred's own personal comments, that the strehl ratios in the visual
wavelengths were not as good as Fred had at first hoped/thought.
None the less, I will personally attest, no color can be detected
visually in focus on any celestial objest with the Apomax.
This is just an example I'm using in that any lens design, can at first
appear to hold great promise as the very best design to come along.
To implement this in the real world, sometimes the design takes "a funny
turn" mark
ValeryD
APO-Max apochromats were better corrected, while not absolutely
optimal for such D and F/D.
VD
ValeryD
> >I have a TMB 100/8. I care not for the lambdas, strhls, wavefronts,
> >spotdiagrams.... I do however care that at least visually, it has cero
> >false color in or out of focus (for whatever purpose you would want to
> >test this out of focus). You can equal that but I know not how you can
> >better it.
OK, I got ARIES 102mm F/6.5 Fluorite Triplet. Zero false colors in focus
and zoro false colors out of focus. Images plain white. Very sharp optics
RMS 0.013 wave. So, which is better zero false color 102mm F/6.5 or
significantly longer 100mm F/8 ???
For a human eye they both are equally color-free. But one is faster (better
for CCD and film photography and wider FOV for deep sky walking) and more
transportable, require less sturdy (and more expensive!) mount.
So, which is better?
VD
ValeryD
TAK's TOA 130. It has fully corrected spherochromatism and
despite it' larger diameter, it has better color correction,
than triplet in question.
VD
CHASLX200
>Date: 11/26/2004 5:39 PM Eastern Standard Time
>Message-id: <5c4a4ee7.04112...@posting.google.com>
>
>
>OK, I got ARIES 102mm F/6.5 Fluorite Triplet. Zero false colors in focus
>and zoro false colors out of focus. Images plain white. Very sharp optics
>RMS 0.013 wave. So, which is better zero false color 102mm F/6.5 or
>significantly longer 100mm F/8 ???
>For a human eye they both are equally color-free. But one is faster (better
>for CCD and film photography and wider FOV for deep sky walking) and more
>transportable, require less sturdy (and more expensive!) mount.
>
>So, which is better?
>
>
>VD
********************************
The f/8 is better for me anyday! I love slower scopes, f/9 or f/11 would even
be a better choice, since i dont image or do astro photo work... Seems like we
dont see many slower APO's these days!
Chas P.
RichA
Same reason you don't see f15 achromats, people don't want them.
-Rich
RichA
Like what I saw comparing Tak's FS-102 against an AP EDF on Jupiter.
Not the surface detail, because the AP was larger, just the AP
provided by far the best colour correction.
MrGrytt
f/9.3) APO from LZOS which should be arriving within the next 2 or 3
months. This figures to be even more highly corrected than the TMB
100/800.
Harvey
mm...@webtv.net (Mark D) wrote in message news:<2889-41A...@storefull-3173.bay.webtv.net>...
Mayer Duda
they are ground and polished no matter what the material.
ValeryD
> see what you write above : all objectives you have in mind to be used
> with your chromacorr
> have such parameter deviations, so you must make your own achromats to
> match them with
> chromacorr to have no such deviations. I know , you will answere me now,
> yes excactly that we will doing,
> fine, but the questions any customer will adresse to you are :
>
> How much such combo will cost shipped to him include tax ?
> What is a real wait time ?
> What is doing afterwards support for the combo ?
>
> can you answere this 3 questions to your customers who want your combo ?
>
> best wishes
> Markus
The question is that you didn't know optics at necessary level and therefore
you just don't know, that achromat's color correction will be essentaily
the same in any objective made of the same design (Synta). What will vary is
only spherical aberration. If you don't believe, ask Roland.
Also, about solutions for low-cost APOs. Read my annoucement here at the
s.a.a. ARIES' H-bomb.
Note, please, this is not a joke and such technology is FAR beyond of any
apo-manufacturing firms.
Valery Deryuzhin.
Craig Levine
>Shut your stupid and ignornant mouth.
Pot, kettle, black.
>Optics are based on how well
>they are ground and polished no matter what the material.
>
So, you're saying that the material is...immaterial? Speaking of
stupid and ignorant... :-P~~~
- Craig
John Savard
part:
>Yes it can, and the TMB 100 f/8 has all the wavelengths
>inside the Airy disk diameter from less than 420nm
>to 706nm,
That certainly is true, and I'm sure you are manufacturing an excellent
telescope.
However, I would be very surprise if your telescope conformed to one of
his other claims: "completely free of spherocromatism". That, of course,
is a design goal one wouldn't really _want_ to try to achieve in the
real world.
Mind you, fluorite double-Gauss lenses have their uses, but they're
generally used as photographic objectives rather than telescope
objectives. And the freedom from spherocromatism is not one of the
important benefits of the design, it is just an incidental result of a
design that, when made symmetrical, has other desirable properties.
John Savard
http://home.ecn.ab.ca/~jsavard/index.html
John Savard
in part:
>So, you'd better advise Tom Back be more modest and not claim, that products
>he sells are best of the best.
I haven't followed the fortunes of TMB Optical closely, but his modest
claim in this thread that his apochromatic scopes are better than an
achromat *of only slightly longer focal ratio* with a color corrector
stuck on the end (and, most important, a standard one bought from stock,
not one designed for the specific achromat) is, I think, one he _can_
get away with.
If his apochromatic telescopes are good enough to be even better than
those from such well-known companies as Vixen and TeleVue, the fact that
there might be other apo makers out there which, like him, nobody has
ever heard of, making equally good telescopes... then, while the claim
you note would still be not precisely accurate, and unfair to the other
makers of equally good telescopes, it would at least not be deceptive to
the majority of consumers.
In other words, their problem is not so much his lack of modesty as
their lack of advertising.
John Savard
http://home.ecn.ab.ca/~jsavard/index.html
John Savard
(John Savard) wrote, in part:
>On 24 Nov 2004 16:34:43 -0800, ar...@mercury.kherson.ua (ValeryD) wrote,
>in part:
>
>>So, you'd better advise Tom Back be more modest and not claim, that products
>>he sells are best of the best.
>
>I haven't followed the fortunes of TMB Optical closely, but his modest
>claim in this thread that his apochromatic scopes are better than an
>achromat *of only slightly longer focal ratio* with a color corrector
>stuck on the end (and, most important, a standard one bought from stock,
>not one designed for the specific achromat) is, I think, one he _can_
>get away with.
When I wrote this, I was not aware that it is your company that designed
the Chromacor corrector, and that it uses a form of glass hitherto
considered impossible to achieve, and that it comes in several different
versions, customized to different amounts of required correction for
spherical aberration.
John Savard
http://home.ecn.ab.ca/~jsavard/index.html
Markus Ludes
>
> APO-Max apochromats were better corrected, while not absolutely
> optimal for such D and F/D.
>
> VD
Valery,
you talking from : I have heard modus. I have owned and sold 3 pc ApoMax
130F/12, all have had very nice optics and very good colorcorrected, but
the visual colorcorrection was far away from the TMB Triplets. I would
say, its colorcorrection , visual could be compared to our TMB 105F/6.2
maximum
Markus Ludes
> TAK's TOA 130. It has fully corrected spherochromatism and
> despite it' larger diameter, it has better color correction,
> than triplet in question.
>
> VD
Valery, again you talking about a scope you have never seen. I have
owned already 2 pc TOA, its colorcorrection is similar to the Tak FCT
6"F/7,sorry to bother you, but visual, the TOA is again not the very
best visuel colorcorrected apo , if you push the power up and you know
what you looking for you will find and see it
Markus Ludes
> The question is that you didn't know optics at necessary level and therefore
> you just don't know, that achromat's color correction will be essentaily
> the same in any objective made of the same design (Synta). What will vary is
> only spherical aberration. If you don't believe, ask Roland.
>
> Also, about solutions for low-cost APOs. Read my annoucement here at the
> s.a.a. ARIES' H-bomb.
> Note, please, this is not a joke and such technology is FAR beyond of any
> apo-manufacturing firms.
>
>
> Valery Deryuzhin.
Valery,
I dont need to be a optical designer to see what I see, right ? I am a
visual
observer and from that point of view I am talking.
About your H-Bomb, let me tell you, my sun knows very well how to use
H-Bomb's,
like many childs, in summer they like to play a lot with them , yes
they have a
impact, by here Mam's reaction :-)
I heard that Thomas is coming with a lot of H-Bomb's, so lets see whose
H-Bomb arrives earlier .
Like many we hate secrets, tell us a bit about the H-Bomb's , please
!!!!!
have a nice weekend
Mark D
you talking from : I have heard modus. I have owned and sold 3 pc ApoMax
130F/12, all have had very nice optics and very good colorcorrected, but
the visual colorcorrection was far away from the TMB Triplets. I would
say, its colorcorrection , visual could be compared to our TMB 105F/6.2
maximum
Markus
Naturally Markus, I KNEW you would say something like this, that the
color correction of the Apomax was "Far Away" from the correction from
the TMB Triplets. Always the salesman, aren't you?
Also too, when you viewed through my Apomax at an Astro-fest , it was in
no way as good as the one you had. Why did I know you would say that?
Right away within 5 seconds you put a number on my scope to say it was
1/6th wave P-V, and to this I say "Bullshit". You don't have
interferometer eyeballs Markus, and neither does Roland, Valery, Thomas,
or whoever.
If they did, they wouldn't have a need for Interferometers, would they?
I'd go as far to say that there was probably NOT ONE Apomax lens that
was figured less than 1/10 wave P-V by Fred.
In fact color correction for the Apomax goes probably well beyond all
the TMB's in both IR and UV, correct?
Yes, I'll agree, and probably Fred would too, that the Apomax did not
display color correction in the visual as Fred had at first hoped.
Thats was Fred's fault for relying on an outside souce/designer for his
lenses. Something I'm sure he'll never repeat again.
Go back, and do a google search on your Apomax review, and see what you
said back then. If I recall correctly you said "at 600X some slight
tinge of color was noted inside, and outside of focus, but none in
focus. Only slightly less color correction in the visual than the best
scopes you've ever had/tested, the Mike Simmons Tak FC-125, and a Zeiss
APQ.
I'm going by memory, but my memory is usually pretty good.
You also state in the review that this was the best lens you have even
seen come from a US Manufacturer.
I know you'd probably say that any TMB designed and being made now is
also better chromatically than any Zeiss APQ ever made also, correct?
Sorry for my sarcasm, but I just don't like it when someone says one
thing, and then says another later on.
If I have made an error on my assumptions on what you said in this old
review, then forgive me, but I'm pretty sure my memory is right.
If I've angered you too also Thomas by my comments, and
assumptions/remarks well then I'm sorry.
I just feel that Markus at times has a tendency to put his foot in his
mouth.
Mark D.
Mark D
was right only color noted inside, and outside focus on Apomax. None
mentioned in focus.
Only mistake I made, FC-125 once belonged to Mike Harvey, not Mike
Simmons. Mark
--------------------------------------------------------------
The Apomax showed me the perfect inside-outside focus image excapt an
ultrafaint diffrence in the outer bright ring, here I noticed an
diffrence in the wideness ( not in sharpness) of about 3 % only.Under
real sky this should be invisible. Yes I could confirm the 1/7.2
wavefront comparaing it with the Zeiss APQ 1/9 wave, side by side. About
the high RMS I was not shure, because the APOMax was smooth, very smooth
smooth but not smoother than the APQ and FC 125 (which have had 1/45
RMS). On monday daytime I received an e-mail from an pre-owner who
informed me, yes with not removed astigmatism it should be around 1/40
wave RMS or slightly better, this confirmed what i saw in comparation
with the APQ.
Colorcorrection: Outsidefocus an faint green visible, insidefocus an
faint deep violett visible at 600 power. I am shure this last colorerror
not comes from the ARIES lens, because the Russian widespaced 102/650
showed at any power zero color, at any focus position, but to be 100%
shure i made this colortest using an reflector and yes , it was the
Apomax. Infocus you must use an 4 mm eyepiece for
390 mm power and an bright star to see an ultrafaint deep purple, If you
dont know for what you are looking , you will not see it. The total
colorcorrection is about the same as the APQ and slightly better as in
the 180F/9 EDT in my stock. Final test with my crazy Ronchigrating 254
lines /inch. The Takahashi and APQ showed perfect images. The test with
Ronchigrating must be done with 3 visible bright lines, here the Apomax
also showed straight lines. Now using just 1 bright line with its 3
faint lines and moving over from inside to outside focus I could detect
an very little curvating, which is not visible on sky. The best
transparency I found in the APQ, which showed the image like you are not
looking through an glas. The Takahashi have the best snap in test and
the faintest first diffraction ring of this 3 scopes. All 3 scopes are
superb and showing an oversized airydisc compare to its faint first
diffraction ring. The Impression of this Apomax to me is like an very
good Zeiss APQ and very similar to Julie Burgers old NIKON ED 100/1200
which was Zygo tested with 1/11 wave and 1/70 RMS too. Because I could
see in the Apomax only in the outerring an diffrence I would rate 95% of
the aperature to be at least 1/12 wavefront.
This is the best USA made lens I have ever seen and I have seen a lot
from 90 mm to 10". From my experience with startesters around the world
who are rating an not perfect 1/5 wave telescope with 1/10 wavefront ,
I am shure the same startesters would rate this Apomax with 1/15 ~ 1/20
wavefront.
RichA
<apm_tel...@web.de> wrote:
>>
>> TAK's TOA 130. It has fully corrected spherochromatism and
>> despite it' larger diameter, it has better color correction,
>> than triplet in question.
>>
>> VD
>
>Valery, again you talking about a scope you have never seen. I have
>owned already 2 pc TOA, its colorcorrection is similar to the Tak FCT
>6"F/7,sorry to bother you, but visual, the TOA is again not the very
>best visuel colorcorrected apo , if you push the power up and you know
>what you looking for you will find and see it
>
>Markus
Any reason there is some colour left? I'd have thought
Tak would have pulled out all the stops when making
this instrument? They did use fluorite for one element,
right?
ValeryD
> >
> > TAK's TOA 130. It has fully corrected spherochromatism and
> > despite it' larger diameter, it has better color correction,
> > than triplet in question.
> >
> > VD
>
> Valery, again you talking about a scope you have never seen. I have
> owned already 2 pc TOA, its colorcorrection is similar to the Tak FCT
> 6"F/7,sorry to bother you, but visual, the TOA is again not the very
> best visuel colorcorrected apo , if you push the power up and you know
> what you looking for you will find and see it
>
> Markus
1. I looked through 150mm F/7 FCT and didn't saw any false color.
You told me, that you too didn't saw any false colors there.
2. These two TOA may be defective. I read several reports with TOA
and nobody were able to detect any false color after a given
scope is fully cooled down.
3. You can easily say, that your saw some colors in your TOAs - in
your marketing intentions. You always saying what is necessary
for you at a given moment.
If only you was a dealer of TAK, I am 200% sure, you will always
say, that neither TOA and FCT show even barest trace of false color!
VD