A. Jaegers 6" F15 Refractor Objective
landrover
1969 so this may be difficult. Still interested in obtaining one of
these, I hear Jaegers is still *in business* but I assume this item is
long gone. Do these ever turn up for sale, and what is the going rate
nowadays?
Alan French
"landrover" <land...@iolmail.co.za> wrote in message
news:fbf5f33.03010...@posting.google.com...
Rod B.
Don't get too nostalgic, not everything that is old is better. I had a
Jaegers 6" back in the early 70's, and sold it to the local planetarium when
I was married. A few years ago, I had one of the import 6" refractors, and
decided to do a comparison of the two. I hadn't looked through the old
Jaegers in 30 plus years, and when I did, I wished I hadn't. It's not that
it wasn't OK, is just wasn't as good as I remembered, and sadly (or
happily?), the import produced a better star test and detail on the moon.
Alan is right, if you are still wanting an achromat, them look to D&G
Optical.
I also had a 1969 GTO with the 400cid engine back then...now there was a
machine that would withstand the test of time.
Rod B.
landrover wrote in message ...
Jan Owen
headers, and a lot of other fun after-market asphalt shredding speed
parts...
Today I have a nice, warmed up 5 liter Mustang GT that can rock and roll
with abandon, but nothing since has been capable of delivering the raw,
gut-twisting, in-your-face, eyeball-flattening, pin-you-in-your-seat, total
acceleration experience that that R/T could offer up any time, any place,
effortlessly...
Not that I would ever think of using that kind of power on the street...
Heheheh!
"Rod B." <blue...@nospamworldnet.att.net> wrote in message
news:DLLR9.95319$hK4.7...@bgtnsc05-news.ops.worldnet.att.net...
Mike Jones
would rather get my 24" Cass finished at least for now.
I ordered and used two 6" f/5 Jaegers "achromats" (loosely termed) for multiplex
holography collimators in grad school back in 1977. Large F-C flare at e-line
focus, but they were both 1/8 wave P-V or better at full aperture at the 514.5
nm argon laser line I was working in - plenty good for what I was doing. Used
with a 32mm eyepiece at 24X, though, they had too much secondary spectrum to
give nice sharp pointy deep sky star images.
Also spent several evenings looking through a Hollywood friend's 6" f/15 Jaegers
back in 1973 and agree with Rod - it wasn't very good imagery, just not the hard
contrast you want. I never had the prescription or took one apart to measure
radii and thicknesses to see why. Ronchi test through a Wratten 12 showed
fairly straight bands so the spherical was fairly well corrected, but residual
color spoiled the broadband image. Better to go with a more modern product.
Optico Fabrication, Inc. at http://www.optilens.com also does occasional runs on
6" BK7/SF2 achromats and does a very good fab job on them. And yes, they will
give you an interferogram if asked.
Mike
Rod B.
gas station. :-)
Rod B.
Jan Owen wrote in message <2aNR9.43644$L61.3...@news1.west.cox.net>...
Jan Owen
But the gas mileage around town was surprisingly good because of the 4:10
rear gears. It would deliver 11 mpg pretty regularly, compared to friends
with hot 383's who were getting around 6 or 7 mpg (of course this same rear
gear ratio made highway driving pretty expensive in a hurry). On the other
hand, at the time, I didn't CARE what the mileage was, it was the gut
wrenching launches and hard acceleration that I bought the car for. The
mileage was just a pleasant surprise given the rest of the package...
On the other hand, spark plugs rarely lasted more than 1000 miles. Rear
tires wore out in one trip across town (well maybe a LITTLE further), and
little things like that added up. The nine quart baffled oil pan hung down
pretty low under the car, and was prone to grounding out on the front side
of dips in the road, twice with horrific consequences, and the header
mufflers had an embarrassing tendency to vibrate loose, then fall off the
car while driving down the road... And picking up a hot header muffler off
the street with your bare hands was not much fun... The throttle return
spring for those big carburetors was pretty stiff, and actually broke a
couple times when the throttle was wide open. Now THAT made for an
interesting trip through rush hour traffic... It wasn't the most reliable
thing on the street, but all the alternatives would be left in it's dust.
The biggest mistake I ever made was selling it to buy a truck to haul my
dirt bikes and telescopes around...
"Rod B." <blue...@nospamworldnet.att.net> wrote in message
news:7r3S9.96862$hK4.7...@bgtnsc05-news.ops.worldnet.att.net...
Marty
> engine back then...now there was a
> machine that would withstand the test of
> time.
Hmmm. At that time I was driving a 1962 Studebaker Lark with outlines
of the Nebraska State Capitol on each door... Wish I still had it,
though. :)
Marty
Karl Moll
Saturdays climbing around in their dumpsters looking for optical
rejects. I recall one day finding a lot of small flats. I thought I'd
struck gold. :-)
On 4 Jan 2003 13:49:10 -0800, land...@iolmail.co.za (landrover)
wrote:
jerry warner
back in the Jaegers era, most everything Jaegers sold was
war surplus and half of that junk. The Jaegers' 6" f/15s were
no Clarks, not even Mogey's, and not Unitrons, so even though time has passed
nostalgia should not change the facts - the
media notwithstanding!
-Jerry
jerry warner
back through the front door and selling them again as surplus?
The dumpster diver industry does it all the time in Iowa City.
Hell, one guy found a whole football team in the dumpster last week and
news tonight is the coach is looking for a new job!
Will wonders never cease.
-Jerry.
Alan French
them are quite good. Unitron lenses also varied and not all were top notch.
"jerry warner" <jwa...@inav.net> wrote in message
news:3E213D06...@inav.net...
jerry warner
with flaws. You could buy the very blanks they made their
achromats from, and I bought a number of these and tried them.
About 50% were unusable. These I sold to European amts who
were desperate to get any 'glass' and willing to take on flawed
flint and crown blanks just to get them. I remenmber one fellow in Copenhagen
who insisted I hand select blanks from him which
I myself was getting direct from Jeagers, and he knew this. He
used to pay phenominal shipping.The fellow was absolutely
convinced he would not get as good a quality as I could provide
simply by ordering direct from Jaegers, so we dealt back and
forth for almost two years, and I was glad to get the business.
But I never saw any Jeagers 4" or larger achromat which tested
as well as Unitron's. The Jaegers 3" and smaller achros were
better, for whatever reason. I still have a Jaegers 6" f/15 and
and it can't compare to modern optics, even the better CR150's
except in the fact it is f/16 vs f/8.
I think Roland has had experience with the Jaeger's glass
in years past. Perhaps he could chime in here.
-Jerry
Dan Chaffee
wrote:
>Not exactly. The glass they used was all war surplus, and often
>with flaws. You could buy the very blanks they made their
>achromats from, and I bought a number of these and tried them.
>About 50% were unusable.
What kinds of flaws; inhomogenity, poor rationality of dispersion,
bad anneal...?
Dan Chaffee
Chris1011
war surplus and half of that junk. The Jaegers' 6" f/15s were
no Clarks, not even Mogey's, and not Unitrons, >>
I hate to tell you, but for a number of years 4" Unitrons used 4" Jaegers
lenses.
Roland Christen
Chris1011
in years past. Perhaps he could chime in here.
-Jerry>>
"Unitrons" were made by Nihon Seiko, and imprted by the Unitron marketing group
here in the US. Nihon Seiko did not have their own optics manufacturing
facility, but did buy lenses from various small time optical shops. There wa sa
time when they could not get lenses from their suppliers, so Unitron did use
Jaegers lenses.
I had a 6" F10 Jaegers lens that was nearly perfect (nothing is perfect). Peter
Ceravolo tested a similar 6" and it was close to 1/10 wave P-V. My mount guy,
Wally, has a 6"F15 Jaegers which is junk.
Roland Christen
Gary Hand
Although much of the Jaegers offerings were W.W.II surplus, the air spaced
telescope objectives were NOT. They were hand corrected Fraunhofer objectives
manufactured at Jaegers. They also supplied them to other companies, Dobbins and
Cave come to mind. They came in 3.15" F/15, 4.25" F/15 and 6" F/5, F/8, F/10 and
F/15. On many occasions, the Unitron people would drive down to Jaegers and
Edmund to get telescope objectives when their original supplier could not
deliver. In fact of the all the hundreds of Unitron I every used, a 4" with a
Jaegers lens was the best. I think you will find them in the same catagory with
the Clarks, Mogeys and Unitrons....folklore reputations not withstanding.
Gary Hand
Gary Hand
parts and a few misc accessories. The Objectives were made by Towa.
Gary Hand
CHASLX200
>From: "Alan French" adfrenchre...@nycap.rr.com
>Date: 1/12/2003 8:42 AM Eastern Standard Time
>Message-id: <yheU9.23392$2z1....@twister.nyroc.rr.com>
>
>Jaegers made their own achromats, so the 6" f/15 was not surplus. Some of
>them are quite good. Unitron lenses also varied and not all were top notch.
>
The optics in my 5" Unitron were very good! That scope could handle over 500x
with ease!!! To bad i sold it, i would pay $12,000 to get get it back.
Chas P
Chris1011
Jaegers lens was the best. I think you will find them in the same catagory
with
the Clarks, Mogeys and Unitrons....folklore reputations not withstanding.
Gary Hand>>
I agree, I have seen some outstanding Jaegers achromats from 3" to 6". But
there are also some real dogs mixed in, we have one here if you want to see it.
Jaegers used various cheap labor to run their polishers. From time to time,
they had some good opticians who would stick around for a while, then leave
because the working conditions in the basement optical shop were so horrendous.
The ceilings were low and dusty with spider webs everywhere. In the summer the
temperature would soar because there was no airconditioning. There were times
when totally unqualified people were making lenses. I've talked to at least one
Jaegers "graduate" who now runs his own optics firm. Old man Jaegers retired in
the '60s to Florida and sold the firm to one of his managers, so there never
really was a true "Jaegers made" lens after that.
Roland Christen
CHASLX200
>Date: 1/13/2003 6:29 PM Eastern Standard Time
>Message-id: <20030113182952...@mb-ch.aol.c
>
>I agree, I have seen some outstanding Jaegers achromats from 3" to 6". But
>there are also some real dogs mixed in, we have one here if you want to see
>it.
>Jaegers used various cheap labor to run their polishers. From time to time,
>they had some good opticians who would stick around for a while, then leave
>because the working conditions in the basement optical shop were so
>horrendous.
>The ceilings were low and dusty with spider webs everywhere. In the summer
>the
>temperature would soar because there was no airconditioning. There were times
>when totally unqualified people were making lenses. I've talked to at least
>one
>Jaegers "graduate" who now runs his own optics firm. Old man Jaegers retired
>in
>the '60s to Florida and sold the firm to one of his managers, so there never
>really was a true "Jaegers made" lens after that.
>
>Roland Christen
*******************************
The last Jaegers i looked thru was a 6" f/10! That had to be the most colorful
scope, i ever saw...
Chas P.
Spoon
> The ceilings were low and dusty with spider webs everywhere. In the summer the
> temperature would soar because there was no airconditioning. There were times
> when totally unqualified people were making lenses. I've talked to at least one
Hey! That sounds just like where I do optics work. Everytime I confront
the owner about it he just stands there staring back at me from the
mirror. Maybe I'll just quit to spite the ugly cuss. <g>
--Mike Spooner
sp...@PageAmerica.net
--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG
Rod B.
had no recollection of it having any color. Oh, it was there all right, but
I did not really notice it until the recent tests mentioned in an earlier
post. As a matter of fact, I can't recall anyone back when (the early 70's)
even bringing up the issue when viewing through it, and that included many
Newtonian users. It's sad in a way that I couldn't see the image quality as
I did back then, focusing instead on all of the technical issues that I've
come to understand.
Rod B.
Alan French wrote in message ...
jerry warner
particulates/impurities, ocassional stress lines ... and
many I dealt with were rough cast so you had to put a
semi polish on them to test them for internal flaws.
It was the lack of consistency that bothered me but again these
(as I understood it) were WWII surplus blanks (or older in
some cases), so it was about what one would expect. Later
quite by accident I stumbled on another surplus supplier (C&H Sales) and
although they lacked the stock Jaegers had, what they did have was
superior, I thought, and none of it catalogued for
general consumption. I made some incredible deals with C&H
in crown and flint (matched) blanks up to 8 inches and most of
these I passed on to European customers. And C&H was just glad to get
rid of their 'orphans'. (If you recall, Roland, it was
at the tailend of this period we corresponded and you sent me a
large spherometer base, which I still have. It was because of these
large blanks and some large lens assemblies I was getting,
I wanted a larger spherometer. I've always kept that spherometer
for sentimental reasons, Roland, because it came from you. Ed
and I were very glad to receive it and you did us a real favor).
-Jerry
Chris1011
for sentimental reasons, Roland, because it came from you. Ed
and I were very glad to receive it and you did us a real favor).
-Jerry>>
Hey, a voice out of my past.
Well, good for you that you were able to help others to get optical supplies,
and I'm glad that my spherometer helped you make lenses.
Roland Christen
JAB
<AnMU9.110214$hK4.8...@bgtnsc05-news.ops.worldnet.att.net>, "Rod B."
<blue...@nospamworldnet.att.net> wrote:
> One interesting aspect of my old Jaegers, which was a 6" f/10, was
> that I had no recollection of it having any color....(snip)... I
> can't recall anyone back when (the early 70's) even bringing up the
> issue when viewing through it, and that included many Newtonian
> users.....
Little doubt that the appearance of Roland's triplets (and Al's
Petzvals) substantially "upgraded" our expectations since those good
old days. Still, I often recall that Henry Paul's favorite telescope
was a Jaeger's 6" f/10 ( and HP must have had almost as many scopes,
refractors and reflectors, as Todd Gross). Assuming that Paul
hand-picked his lens, I wonder is there something special about the 6"
f/10 formula.
--
John
(to reply directly, change 'refuse' to 'fuse' and 'com' to 'net')
Chris1011
Special?? In what way??
Even the most rudimentary knowledge of optics allows anyone to design a 6" F10
achromat using just about any crown and flint glasses, and the result will be
just about the same. In fact an expert designer cannot much improve the color
correction over what a beginner can manage. The color error will be there just
like the coma will be there in any given size Newtonian mirror.
You can move the color around the spectrum, for instance to lower the error in
blue, but this will automatically increase the error at the other end in the
red. You have only so much wavelength range that will be in focus, and where in
the wavelength range you choose that focus to be is sometimes called
"optimizing", but this does not in any way reduce the overall color error,
neither does it increase the wavelength range that will be in critical focus.
It seems to be an eternal hope and wish that somehow a better achromat can be
designed if only the design is "optimized" or some special glass is used. The
only way to get meaningful color correction and to extend the wavelength range
that is in critical focus is to use expensive abnormal dispersion glass (ED
glass and Fluorite fall into this category). Crown and flints that lie along
the Abbe normal line will not do the trick. Any glass that lies substantially
off the Abbe normal line will be an order of magnitude more expensive than
normal crown and flint. There really is no way around this.
Roland Christen