Re: TEC APO 160 costs $12,000 ??
Ratboy99
>with a different set of specs. The scope was announced as $8000 originally
>when it was to be an upscaled 140.
>
>Regards,
>Ed T.
>
I also somehow doubt (though I am not an insider by any means), that there will
be too many more 200's sold at only $15,999, either. I'd get it right now if
you are even remotely thinking about it.
rat
~( );>
email: remove 'et' from .com(et) in above email address
Jeff Marsh
now a bit odd:
APO 140 = $4,600 (F/7)
APO 160 = $12,000 (F/8)
APO 200 = $15,999 (F/9)
It takes an extra $7400 to go from 140mm to 160mm? Wow, that's a big
step for 20mm. And it seems that if you would spend that much for a
160 then you would go ahead and spend another $3,999 to get a 200
instead. Is that the idea?
But in a way it is an encouraging trend for high-end customers. Maybe
Yuri could make an APO 300 for, say, $18,000. : )
Jeff Marsh
(who wouldn't mind having an TEC140 someday...)
John Boudreau
"Jeff Marsh" <jeffrey...@verizon.net> wrote in message
news:50ed606.04101...@posting.google.com...
> TEC is taking orders for a 160 mm APO. But TEC's price structure is
> now a bit odd:
>
> APO 140 = $4,600 (F/7)
> APO 160 = $12,000 (F/8)
> APO 200 = $15,999 (F/9)
>
> It takes an extra $7400 to go from 140mm to 160mm? Wow, that's a big
> step for 20mm. And it seems that if you would spend that much for a
> 160 then you would go ahead and spend another $3,999 to get a 200
> instead. Is that the idea?
That's because the APO 160 will have a fluorite center element, not the
FPL-53 used in the APO 140 and most of the APO 200's. Originally, the APO
160 was to use FPL-53 and would have cost $8000.
Yuri announced this on the TEC Yahoo Group a few months ago.
John
rander3127
wrote:
So does the extra $4000 account for the cost of the fluorite compared
to FPL-53 or is the fluorite that much harder to work?
rander3127
>
>"Jeff Marsh" <jeffrey...@verizon.net> wrote in message
>news:50ed606.04101...@posting.google.com...
>> TEC is taking orders for a 160 mm APO. But TEC's price structure is
>> now a bit odd:
>>
>> APO 140 = $4,600 (F/7)
>> APO 160 = $12,000 (F/8)
>> APO 200 = $15,999 (F/9)
>>
>>
>
>From what I hear, the TEC 160 is now going to be an ultra high end scope
>with a different set of specs. The scope was announced as $8000 originally
>when it was to be an upscaled 140.
>
>Regards,
>Ed T.
>
That's what I like about apo makers. Every scope they bring out is
perfect, until they release the next one.
Stephen Paul
"Ratboy99" <ratb...@aol.comet> wrote in message
news:20041015224346...@mb-m17.aol.com...
> >That's because the APO 160 will have a fluorite center element, not the
>>FPL-53 used in the APO 140 and most of the APO 200's.
>
> or is
> it $28k now? All I know is I'm getting ready to take the 200 F9 out
> tonight.
> Whoooweee!!
I'd be happy to get the C102 F5 out there... stupid rain.
JJK
> >From what I hear, the TEC 160 is now going to be an ultra high end scope
> >with a different set of specs. The scope was announced as $8000
originally
> >when it was to be an upscaled 140.
Ratboy99 wrote
> I also somehow doubt (though I am not an insider by any means), that there
will
> be too many more 200's sold at only $15,999, either. I'd get it right now
if
> you are even remotely thinking about it.
Is the TEC 8" apo really worth it?
John Boudreau
"rander3127" <rande...@rogers.com> wrote in message
news:b901n0l0mpbm6l0gc...@4ax.com...
>
>
> So does the extra $4000 account for the cost of the fluorite compared
> to FPL-53 or is the fluorite that much harder to work?
>
Both. Mostly the cost of the fluorite itself, but there is also more work
involved.
I'm not sure, but I believe the crowns used to work with a fluorite element
are also somewhat more expensive than those typically used for FPL-53.
John.
John Boudreau
"Ratboy99" <ratb...@aol.comet> wrote in message
news:20041015224346...@mb-m17.aol.com...
>
> Well that makes sense. The APO 200 F8 (with Fluorite) is more like $24k,
> or is
> it $28k now? All I know is I'm getting ready to take the 200 F9 out
> tonight.
> Whoooweee!!
> rat
> ~( );>
I'm jealous... but mostly because it's raining here <g>. My APO140 is a
blast, but I can imagine what an APO200 must be like. Congratulations on
what I'm sure is an outstanding scope!
John
Guy Macon
rander3127 <rande...@rogers.com> says...
>So does the extra $4000 account for the cost of the fluorite compared
>to FPL-53 or is the fluorite that much harder to work?
It's worth the extra cost to avoid tooth decay.
M D
superior to Ohara FPL-53? In what ways will the Flourite triplet
outperform, or have advantages over a properly designed, and properly
figured FPL-53 triplet?
Is Yuri perhaps striving for an f5 highly corrected Triplet with the use
of Flourite, or am I missing something here?
I would assume that even lower grades of Ohara ED (FPL-51 FPL-52) can be
utilized into fantastic triplet designs, but perhaps with longer FL's?
I know FPL-53 is not cheap by no means, but really, is it worth this
increase in cost to utilize Flourite. Will the Human eye, or the CCD
Sensor "See" the difference?
Will the use of Flourite ED have any downsides in I assume an oil
contacted design? Mark D.
Ratboy99
Yes.
Ratboy99
>blast, but I can imagine what an APO200 must be like. Congratulations on
>what I'm sure is an outstanding scope!
I don't blame you. Hell, I'm even jealous of myself!
Ratboy99
>superior to Ohara FPL-53? In what ways will the Flourite triplet
>outperform, or have advantages over a properly designed, and properly
>figured FPL-53 triplet?
I think I know the answer to this question. The Fluorite is an F8, it is a
shorter OTA than the F9. It also has better color correction in the
photographic wavelengths. So it will exhibit less color in photographs.
The F9 is optimized for visual use, due to the the narrow sensitivity of the
human eye to the visual spectrum. I can see a bit of color out of focus on
bright objects, but even on bright objects, such as Vega, I have to work to see
the false color when the scope is in focus. For example there is no false color
in focus on the edge of the Moon. Vega is the only single object that I have
been able to detect a fleeting purple fringe on, and I mean fleeting. Any other
color I've seen in it (such as on Venus) has plainly been due to atmospheric
refraction, not false color in the objective. I think with perfect seeing I
would be able to focus the color on Vega right out of view.
It outperforms myTak 6" in this respect by leaps and bounds, and trust me, the
Tak is no slouch. It also gobbles up eyepieces better than the Tak. What is
amazing is splitting .53 arcsec doubles to the Dawes limit at 600x. This scope
does things performance-wise that none of the other 12 scopes that I have
owned have been able to even approach, regardless of aperture or optical
figure.
Marc Zukoff
As another Tec 200mm apo. owner I can say resoundingly, Yes!, it is
worth it. In fact at 16K., it may even be a bargain if you look at
what the AP 180 F9 sells for and the Tak is over 100K, and the TMB
21K. I think Yuri is underpricing these scopes.
I have owned many other fine scopes, including apo's, newts, and
maks. The Tec 200 is the finast scope I have ever looked through. It
splits sub-arc second doubles with ease, something I have never been
able to do before with my average N.J. seeing. Saturn is breathtaking.
A work of art.
Marc Zukoff
"JJK" <sur...@erols.com> wrote in message news:<TfWdneZsgqr...@rcn.net>...
CHASLX200
>From: yoo...@yahoo.com (Marc Zukoff)
>Date: 10/16/2004 9:46 AM Eastern Daylight Time
>Message-id: <13b79f5e.04101...@posting.google.com>
>
********************************
Maybe i should buy one! I have the seeing that would make owning a 8" APO
worth while. Now if i could only find a good AP-1200 mount...
Chas P.
Chris1011
>FPL-53 used in the APO 140 and most of the APO 200's.
Well that makes sense. The APO 200 F8 (with Fluorite) is more like $24k, or is
it $28k now? All I know is I'm getting ready to take the 200 F9 out tonight.
Whoooweee!>>
Do you think adding fluorite would make your scope any better? Yours does not
even have FPL53 in it.
Roland Christen
Chris1011
>outperform, or have advantages over a properly designed, and properly
>figured FPL-53 triplet?
I think I know the answer to this question. The Fluorite is an F8, it is a
shorter OTA than the F9. It also has better color correction in the
photographic wavelengths. So it will exhibit less color in photographs.>>
No, the real answer is that you cannot get FPL53 in that size. Ohara refuses to
make it larger than 7". I have tried for years to get it, and they refuse
because they say their yield drops rapidly above that point.
Fluorite is now available in much larger sizes, in fact I just got information
about a 300mm diameter size. The drive behind these sizes is not amateur
astronomical, rather it is mainly aimed at the semiconductor industry for
stepper lenses. larger sizes = finer resolution of line widths. Used to be that
6" stepper lenses were the norm, but now ever larger sizes are being ordered.
Roland Christen
Richard F.L.R. Snashall
Chris1011 wrote:
>>>superior to Ohara FPL-53? In what ways will the Flourite triplet
>>>
>>>
>>outperform, or have advantages over a properly designed, and properly
>>figured FPL-53 triplet?
>>
>>
>
>I think I know the answer to this question. The Fluorite is an F8, it is a
>shorter OTA than the F9. It also has better color correction in the
>photographic wavelengths. So it will exhibit less color in photographs.>>
>
>No, the real answer is that you cannot get FPL53 in that size. Ohara refuses to
>make it larger than 7". I have tried for years to get it, and they refuse
>because they say their yield drops rapidly above that point.
>
>
How about using N-FK56, then?
>
>Roland Christen
>
>
--
Rick S.
CHASLX200
>Date: 10/16/2004 1:26 PM Eastern Daylight Time
>Message-id: <20041016132629...@mb-m17.aol.com>
>
>Do you think adding fluorite would make your scope any better? Yours does not
>even have FPL53 in it.
>
>Roland Christen
**********************************
To some people Fluorite is the magic lens.
I dont buy it! I've owned enough APO's without fluorite, a older 6"f/9 AP
Starfire and a Brandon 94mm with AP lens and a few others. Also i've ownd a
few Taks with fluorite, and the older coated non fluorite AP's were just as
sharp and contrasty.
Why in the hell anyone would pay double the price for fluorite in 7" plus size
lens beats me!!!
Chas P.
Rank Amateur
leaving aside the difference in aperture between your TEC 8" and your Tak 6"
and, if possible, the difference in color correction, how do you rate the
TEC's optics versus the Tak's optics? That is, do you think the figure and
polish of the Tak are comparable to the figure and polish of the TEC, or is
the TEC distinctly better?
bill g.
"Ratboy99" <ratb...@aol.comet> wrote in message
news:20041016032902...@mb-m21.aol.com...
Ratboy99
>even have FPL53 in it.
>
>Roland Christen
No, I don't, at least for visual purposes. It would make it a bit more
portable, but I am perfectly happy with its size.
Ratboy99
>
>leaving aside the difference in aperture between your TEC 8" and your Tak 6"
>and, if possible, the difference in color correction, how do you rate the
>TEC's optics versus the Tak's optics? That is, do you think the figure and
>polish of the Tak are comparable to the figure and polish of the TEC, or is
>the TEC distinctly better?
>
>bill g.
For some reason (my eyes, optical figure, rare good seeing conditions), I have
been able to push the TEC much higher in terms of x per inch than I have been
able to with any other scope.
Incredibly tight doubles (.53 - .58 arcsec) are being pleasantly observed at
600x.
Best I've been able to do with the 6" tak is .9 or so. But then I haven't tried
that hard. I need to get it on some .75" doubles and see how it does.
First look at Saturn the other night with the 200 was awesome at 383x with a
binoviewer.
It's weird, kind of put my ideas of what I thought possible with my eyes into a
new perspective.
Jupiter will be the real test object. If I am able to use in excess of 225x on
a regular basis I am then going to have to say it is the scope.
The 6" Tak is usually best for Jupiter at about 180x, 200x max.
The 10" Zambuto Newt maxes out usually at 200x as well (sometimes able to use
225x to good effect).
But the one thing that I know for certain that I have never had a scope that
was just cruising on Saturn at 383x, especially using a bino...
CHASLX200
>From: ratb...@aol.comet (Ratboy99)
>Date: 10/16/2004 3:04 PM Eastern Daylight Time
>Message-id: <20041016150411...@mb-m03.aol.com>
>
>
>For some reason (my eyes, optical figure, rare good seeing conditions), I
>have
>been able to push the TEC much higher in terms of x per inch than I have been
>able to with any other scope.
>
>Incredibly tight doubles (.53 - .58 arcsec) are being pleasantly observed at
>600x.
>
>Best I've been able to do with the 6" tak is .9 or so. But then I haven't
>tried
>that hard. I need to get it on some .75" doubles and see how it does.
>
>First look at Saturn the other night with the 200 was awesome at 383x with a
>binoviewer.
>
>It's weird, kind of put my ideas of what I thought possible with my eyes into
>a
>new perspective.
>
>Jupiter will be the real test object. If I am able to use in excess of 225x
>on
>a regular basis I am then going to have to say it is the scope.
>
>The 6" Tak is usually best for Jupiter at about 180x, 200x max.
>
>The 10" Zambuto Newt maxes out usually at 200x as well (sometimes able to use
>225x to good effect).
>
>But the one thing that I know for certain that I have never had a scope that
>was just cruising on Saturn at 383x, especially using a bino...
>rat
>~( );>
>*****************************************
Boy the seeing really limits you, i dont even get warmed up below 500x...
Chas P.
Chris1011
>>
Schott is totally unresponsive about this material. They are not prepared to
quote me anything in reasonable sizes for astronomical objectives.
Roland Christen
Ratboy99
aside the difference in aperture." The difference in aperture is by far the
overriding difference between the two scopes and there is no way to separate it
out in comapring theme, it is simply too great a factor.
As to your other questions, the figure and polish in both scopes are excellent.
There is some spherochromatism affecting the out of focus images using each
scope, so neither of them are easily evaluated for optical figure using the
handy dandy star test. I don't have a green interferometer on me, so...
Both scopes have very smooth, sharp optics that positively snap into focus.
From what I know of Yuri and his boys, I think they lavish a great deal of
effort on getting the TEC lenses absolutely perfect.
From what I've seen, I believe that TEC has developed a deep sense of personal
pride regarding the fact that they fabricate their optics "in house." Anyone
involved in producing a high quality product realizes that this pride is itself
is a fuel that drives the quest for perfection.
And while Takahashi subs their lens sets out to another company (a subsidiary
of Canon?) , they, too, obviously have optics that are fabricated to a very
high spec.
They are both great scopes.
In ending it is worth noting that I have not had the Tak out even once, even to
do a side by side, since having received the TEC two months ago.
>>leaving aside the difference in aperture between your TEC 8" and your Tak 6"
>>and, if possible, the difference in color correction, how do you rate the
>>TEC's optics versus the Tak's optics? That is, do you think the figure and
>>polish of the Tak are comparable to the figure and polish of the TEC, or is
>>the TEC distinctly better?
>>
>>bill g.
rat
Ratboy99
>to
>make it larger than 7".
Yeah, I knew it wasn't FPL53 already. Yuri wouldn't tell me what it really is,
but when I am using the scope it looks more like FPL52.
Marc Zukoff
Hmmm, I wonder what glass is in my Tec 200. I thought is was
FPL-53. I know if I ask Yuri, he will tell me it is Russian Vodka:-)
Whatever glass is being used it sure works well.
Marc Zukoff
chri...@aol.com (Chris1011) wrote in message news:<20041016133420...@mb-m17.aol.com>...
rander3127
>>rat,
>>
>>leaving aside the difference in aperture between your TEC 8" and your Tak 6"
>>and, if possible, the difference in color correction, how do you rate the
>>TEC's optics versus the Tak's optics? That is, do you think the figure and
>>polish of the Tak are comparable to the figure and polish of the TEC, or is
>>the TEC distinctly better?
>>
>>bill g.
>
>
>For some reason (my eyes, optical figure, rare good seeing conditions), I have
>been able to push the TEC much higher in terms of x per inch than I have been
>able to with any other scope.
>
>Incredibly tight doubles (.53 - .58 arcsec) are being pleasantly observed at
>600x.
>
>Best I've been able to do with the 6" tak is .9 or so. But then I haven't tried
>that hard. I need to get it on some .75" doubles and see how it does.
This must tie in with eyesight as I have no trouble under good seeing
conditions splitting 0.6" or slightly under equal doubles with a good
C8. Unequal doubles are another issue though.
-Rich
Rank Amateur
Thanks for your comments. You are lucky to have two such wonderful scopes.
I asked about your FS-152 because I tire of folks belittling the Takahashi
FS series of fluorite doublet refractors. Several times I have communicated
with folks who dismiss the Takahashis as inferior-grade "semi-apo's," and it
always irritates the heck out of me. I have an FS-128, and I think it's
great.
Bill
"Ratboy99" <ratb...@aol.comet> wrote in message
news:20041016173705...@mb-m11.aol.com...
CHASLX200
>Date: 10/16/2004 7:37 PM Eastern Daylight Time
>Message-id: <fhicd.5904$gy1....@newsread1.news.pas.earthlink.net>
>
>Thanks for your comments. You are lucky to have two such wonderful scopes.
>
>I asked about your FS-152 because I tire of folks belittling the Takahashi
>FS series of fluorite doublet refractors. Several times I have communicated
>with folks who dismiss the Takahashis as inferior-grade "semi-apo's," and it
>always irritates the heck out of me. I have an FS-128, and I think it's
>great.
>
>Bill
******************************
I've owned four Taks, all were excellent!
The FS-78 was my fav...
Chas P.
rander3127
<bgree...@earthlink.net> wrote:
>Hi, Rat,
>
>Thanks for your comments. You are lucky to have two such wonderful scopes.
>
>I asked about your FS-152 because I tire of folks belittling the Takahashi
>FS series of fluorite doublet refractors. Several times I have communicated
>with folks who dismiss the Takahashis as inferior-grade "semi-apo's," and it
>always irritates the heck out of me. I have an FS-128, and I think it's
>great.
>
>Bill
>
Problem with Taks is:
-Not perfect colour correction in the doublets.
-A colour shade of yellow cast on everything compared with an (for
eg.) AP Triplet.
-Variability of the quality of the optics, ranging from 1/3rd wave
(reportedly) to 1/8th wave. My FS-102 was around 1/6 wave.
My FS-78 was 1/8th wave.
Ratboy99
>(reportedly) to 1/8th wave. My FS-102 was around 1/6 wave.
>My FS-78 was 1/8th wave.
I'm curious as to how you determined these correction figures. Do you have an
interferometer?
Craig Levine
I mentioned the deal on the 200mm (I have an AP 102MM) to my wife. I
caught a glare that would kill a small amphibian at 50 paces. :-)
Incidentally, with a scope like that, you just GOTTA get either a 90mm
Ha filter from Coronado, or a full aperture one from their primary
competitor. The views of the Sun would make one weep.
- Craig
Ratboy99
>with folks who dismiss the Takahashis as inferior-grade "semi-apo's," and it
>always irritates the heck out of me. I have an FS-128, and I think it's
>great.
That's weird. I never hear people denigrate the Tak's. You should have heard
the comments surrounding mine at the star parties during the Mars opposition. I
love my FS-152. Semi-apo? Ha!
Ratboy99
>(reportedly) to 1/8th wave. My FS-102 was around 1/6 wave.
>My FS-78 was 1/8th wave.
BTW, whoever thought they had a 1/3 wave Tak either didn't know what the hell
they were talking about (most likely) or could have simply returned it. I
suspect that they are all figured to a minimum 1/6th wave. That is a pretty
damned good scope considering that there is no contrast robbing CO involved.
rander3127
>>-Variability of the quality of the optics, ranging from 1/3rd wave
>>(reportedly) to 1/8th wave. My FS-102 was around 1/6 wave.
>>My FS-78 was 1/8th wave.
>
>I'm curious as to how you determined these correction figures. Do you have an
>interferometer?
>rat
Just based on star tests and the fact I've seen scopes that had been
on interferometers and know what star tests look like in them.
To put it more carefully then, I know my FS-78 was better than my
FS-102 and my FS-102 was better than 1/4 wave.
-Rich
rander3127
>>-Variability of the quality of the optics, ranging from 1/3rd wave
>>(reportedly) to 1/8th wave. My FS-102 was around 1/6 wave.
>>My FS-78 was 1/8th wave.
>
>BTW, whoever thought they had a 1/3 wave Tak either didn't know what the hell
>they were talking about (most likely) or could have simply returned it. I
>suspect that they are all figured to a minimum 1/6th wave. That is a pretty
>damned good scope considering that there is no contrast robbing CO involved.
>rat
Sure they could, but that really wasn't the issue, it was that a 1/3rd
wave Tak existed at all. Lets just say the observation that Tak
lenses varied in quality came out of Europe. There is still something
like this thinking today. Ever notice the people looking for the old
FC-100s instead of FS-102s?
Rank Amateur
The folks who denigrate the Tak doublets are generally folks who have never
actually looked through a Tak doublet.
Bill
"Ratboy99" <ratb...@aol.comet> wrote in message
news:20041016203923...@mb-m11.aol.com...
Joe Bergeron
<ratb...@aol.comet> wrote:
> In ending it is worth noting that I have not had the Tak out even once, even
> to
> do a side by side, since having received the TEC two months ago.
Well, you may be proud of your Tak and your TEC, but I now have a Tik,
and may upgrade to a Tok, and maybe even eventually a Tuk.
--
Joe Bergeron
Ratboy99
>wave Tak existed at all.
That's what I am actually in doubt of.
Ratboy99
>and may upgrade to a Tok, and maybe even eventually a Tuk.
I was thniking mchu teh sme thngi. My afingers were beeconmig tongue err fniger
tied just rtying to type TEC and TAK all the tmie.
rander3127
>>Sure they could, but that really wasn't the issue, it was that a 1/3rd
>>wave Tak existed at all.
>
>That's what I am actually in doubt of.
>rat
I've looked though lots of Taks and I've never seen one either.
ValeryD
<snip>
> There is some spherochromatism affecting the out of focus images using each
> scope, so neither of them are easily evaluated for optical figure using the
> handy dandy star test.
<snip>
> rat
> ~( );>
Hello Rat,
Yes, spherochromatism is a common annoying enough aberration in all
fast APOs.
The only way out is to bring lenses wider in APO triplet. But this
makes
objective quite sensitive to temperature changes and such objectives
have
much longer cool down time and at some circumstances can't be cooled
down
at all.
Another way is to use an achromat with Chromacor-II combination. This
device
fixes spherochromatism completely and it also has almost perfect color
correction.
We, at the ARIES, have plans to bring someday on the market such a
scope as
8" F/8 + Chromacor-IV (as fully pre-installed and unremoveable), where
image
quality will be really reflector-like in terms of color correction and
refractor-like in terms of contrast and pin-point images.
Valery Deryuzhin
ARIES.
Ratboy99
>
>Yes, spherochromatism is a common annoying enough aberration in all
>fast APOs.
It's not especially annoying, I just mentioned it because I can see it. It is
present in all four of my APO's.
>The only way out is to bring lenses wider in APO triplet. But this
>makes
>objective quite sensitive to temperature changes and such objectives
>have
>much longer cool down time and at some circumstances can't be cooled
>down
>at all.
Yes, like the Tak TOA - no thanks - I've got enough problem with cool down
already...
>We, at the ARIES, have plans to bring someday on the market such a
>scope as
>8" F/8 + Chromacor-IV (as fully pre-installed and unremoveable), where
>image
>quality will be really reflector-like in terms of color correction and
>refractor-like in terms of contrast and pin-point images.
Uh huh (nodding head), I believe you.
rander3127
wrote:
>ratb...@aol.comet (Ratboy99) wrote in message news:<20041016173705...@mb-m11.aol.com>...
>
><snip>
>> There is some spherochromatism affecting the out of focus images using each
>> scope, so neither of them are easily evaluated for optical figure using the
>> handy dandy star test.
><snip>
>> rat
>> ~( );>
>
>Hello Rat,
>
>Yes, spherochromatism is a common annoying enough aberration in all
>fast APOs.
>
>The only way out is to bring lenses wider in APO triplet. But this
>makes
>objective quite sensitive to temperature changes and such objectives
>have
>much longer cool down time and at some circumstances can't be cooled
>down
>at all.
Meade's 7" doublet ED takes almost 2 hours to cool down going from
20 deg. C to -5 deg. C.
Ratboy99
>20 deg. C to -5 deg. C.
That's terrible. My 8" TEC triplet cools down fast.
Yuri
> This information now begs the question, "Why will the Flourite ED be
> superior to Ohara FPL-53? In what ways will the Flourite triplet
> outperform, or have advantages over a properly designed, and properly
> figured FPL-53 triplet?
>
> of Flourite, or am I missing something here?
>
> I would assume that even lower grades of Ohara ED (FPL-51 FPL-52) can be
> utilized into fantastic triplet designs, but perhaps with longer FL's?
>
> I know FPL-53 is not cheap by no means, but really, is it worth this
> increase in cost to utilize Flourite. Will the Human eye, or the CCD
> Sensor "See" the difference?
> Will the use of Flourite ED have any downsides in I assume an oil
> contacted design? Mark D.
Here are a few reasons to make APO160 and further APO180 with CaF2 as
a middle element:
1. No dimesional limitations, CaF2 is available in sizes up to 12";
FPL53 cut blanks are limited by slab width, see sample:
http://www.ImageHosting.com/images/Yuri/slab.jpg
2. All three glasses in APO160 are available from stock
3. Choosen glasses are not new for us - that is important.
4. CaF2's refractive index is a constant (!); we have to do
measurements for two glasses only, instead of 3 as for ED glass design
5. We have better color corection in given glass combination than,
lets say, in APQ of similar ratio
6. Design could be forsed to 160 F/7 and still have better color
corection than in ED combination, like APO140 with FPL53 as a middle
element.
7. Monocrystals of CaF2 have better homogeneity than given size
blanks of ED glass, since they have to re-process at least twice to
make them bigger - nver a good idea
8. Less scatter in CaF2 (it is not a glass) is a (+) too , see
http://www.ImageHosting.com/images/Yuri/cafvsed.jpg
Of coarse there is one (-) in all above - the cost of high quality
monocrystall of CaF2 is high - a few times more than all of thee
glasses for APO140 - that is why 20mm difference in dia. + all above
makes price so difference.
Regards, Yuri
PS
We found CaF2 as a very good material to work with!
CHASLX200
>Date: 10/18/2004 9:41 PM Eastern Daylight Time
>Message-id: <20041018214134...@mb-m14.aol.com>
>
>
>That's terrible. My 8" TEC triplet cools down fast.
>rat
>~( );>
********************************
You thinks thats bad,my Meade 7" ED never stayed collimated! So it never had a
chance to cool down...
Chas P.
rander3127
Thanks for posting this. The pictures are fascinating
and your last comment should really gives people confidence
in your ability to produce excellent optics since every other
optician/pundit has pronounced fluorite difficult to work.
!
Leonard
Hi Yuri ,
There must be some down side to this material
compared to ED glass ? Shock resistance ? expansion/contraction in
larger sizes ? Something other than cost .
Leonard
Yuri
> Hi Yuri ,
>
> There must be some down side to this material
> compared to ED glass ? Shock resistance ? expansion/contraction in
> larger sizes ? Something other than cost .
> Leonard
Leonard,
the only one thing that I can say was issue in the begining - mental
feeling when you are working with substrate that costs thousands!, but
technically there are no down sides to CaF2 vs. EDs (BTW, ED glasses
are kind of melted form of CaF2).
Yuri
Leonard
> Leonard,
> the only one thing that I can say was issue in the begining - mental
> feeling when you are working with substrate that costs thousands!, but
> technically there are no down sides to CaF2 vs. EDs (BTW, ED glasses
> are kind of melted form of CaF2).
> Yuri
Hello Yuri ,
Thanks , Hope everyone at TEC is well and keep up the good
work !
Leonard
Lucky TEC 140 owner , one fine instrument .
Greg Chapel
TeleVue TV-102 package available for purchase on AstroMart.
The package includes clamshell case, 2" TV Everbrite diagonal, TV 20mm pl,
mounting rings, 2"- 1-1/4" adapter, TV StarBeam Finder, TV Ash Gibralter
mount, TV PowerMate 2.5, Baader solar filter designed for TV 4" objective,
Manual signed by Al, and original TV Packaging.
All total the original purchase price was over $3900.00.
Asking $2700.00, current auction price $2225.00.
Please see either AstroMart ad #305900 or auction #622 for more details and
pictures.
Must sell everything!
moT
> All total the original purchase price was over $3900.00.
> Asking $2700.00, current auction price $2225.00.
>
> Please see either AstroMart ad #305900 or auction #622 for more details
and
> pictures.
>
> Must sell everything!
Did you miss one too many support payments?
Greg Chapel
<M...@nospam.com> wrote:
No I have two boys in out of state colleges.