habsburg8
scholastic sledgehammer
Reged: 07/07/05
Posts: 946
|
|
To date, these Sears 90mm f/16 telescopes have surfaced. The upper limit of telescopes imported and sold by Sears is still unknown, but may be in the 400-600 range.
(1) #990112 (John S. of Oregon)
(2) #990141 (Richard D. of Colorado)
(3) #990152 (John S. of Oregon)
(4) #990180 (Doug D. of Louisiana)
(5) #990270 (Robert F. of Connecticut)
(6) #990318 (Karl S. of Washington)
(7) #990320 (Michael W. of Illinois)
(8) #990370 (Michael W. of Illinois)
(9) #990381 (Brad M. of Washington)
(10) #990383 (Michael W. of Illinois)
(11) #990... (Richard A. of Oklahoma)
The remaining scopes are either in the hands of dedicated amateur astronomers (who don't know or care about their rarity and value), average citizens who bought one or received one as a kid, or hidden in basements and attics collecting layers of dust.
As time goes on more and more of these instruments will be reaching the marketplace. Previous owners are aging and their former scopes are now showing up at estate sales and auctions. Based on past statistics, about 2 or 3 new examples per year will become available for purchase. Since most everyone is now on the lookout for one, any and all existing scopes will disappear from the marketplace quite quickly.
Edited by habsburg8 (10/20/09 08:56 PM)
|
habsburg8
scholastic sledgehammer
Reged: 07/07/05
Posts: 946
|
|
Last night I had my Sears #6345 90mm f/16 refractor (serial number 990152) out under the stars. Here in Oregon there was a scattering of high clouds, but I still got some amazing views of deep-sky objects. The view of Messier 35 and its companion cluster was the best in my lifetime through the Sears 90mm, and I have looked at this beautiful open cluster in Gemini countless thousands of times.
It had an almost 3-D effect in the Sears refractor. Star images were absolutely tack sharp and were etched against a jet black sky background. The stars almost appeared to jump out of the eyepiece at the observer.
The only comparable view that I had was in Roland Christen's original 5" f/13 apochromatic or triplet objective lens (his "Stellafane Winner" from the early 1980s), but the Sears 90mm gave a better overall performance. This custom NASA glass from decades ago is the only optical material that approaches the Sears 90mm lens in clarity of image.
Edited by habsburg8 (10/20/09 08:38 PM)
|
woodsman
Pooh-Bah
Reged: 03/12/08
Posts: 1356
Loc: Colorado Springs, CO
|
|
John,
What about scopes that may have been taken out of the country or up North to Canada. I would imagine that there were Sears Roebuck stores up there in Canada or perhaps some on the border where people traveled down and purchased them. What do you think about that possibility. Rich
--------------------
artisticwoods
C-14 Orange Tube, C-8, C-5, C-90 Astro Model, C8 Schmidt Camera 8" f1.5, C5.5 Schmidt Camera f1.65, SPI 42mm f/19 Refractor, Sears 90mm f/15.56 Ref, Sears 80mm f/15 Ref, Scope 60mm f/11.7, Sears 50mm f/12
Unitron Model 140 75mm/1200mm, Unitron model 128 60mm/900mm
|
woodsman
Pooh-Bah
Reged: 03/12/08
Posts: 1356
Loc: Colorado Springs, CO
|
|
John,
Have you ever done any research as to why the 90mm was only available through Sears? Since Astro Optical seems to have never produced any of these scopes for insertion into their catalogs, it would seem that Sears made certain that they were the only outlet available to get these scopes. If there were 400-600 produced, how do you think that would compare to the Unitron 152? Would you imagine that Unitron produced something approaching that number of scopes in their 4 inch model? 
--------------------
artisticwoods
C-14 Orange Tube, C-8, C-5, C-90 Astro Model, C8 Schmidt Camera 8" f1.5, C5.5 Schmidt Camera f1.65, SPI 42mm f/19 Refractor, Sears 90mm f/15.56 Ref, Sears 80mm f/15 Ref, Scope 60mm f/11.7, Sears 50mm f/12
Unitron Model 140 75mm/1200mm, Unitron model 128 60mm/900mm
|
AlienFirstClass
Pooh-Bah
Reged: 02/13/09
Posts: 1149
|
|
Quote:
To date, these Sears 90mm f/16 telescopes have surfaced. The upper limit of telescopes imported and sold by Sears is still unknown, but may be in the 400-600 range.
(1) #990112 (John S. of Oregon)
(2) #990141 (Richard D. of Colorado)
(3) #990152 (John S. of Oregon)
(4) #990180 (Doug D. of Louisiana)
(5) #990270 (Robert F. of Connecticut)
(6) #990318 (Karl S. of Washington)
(7) #990320 (Michael W. of Illinois)
(8) #990370 (Michael W. of Illinois)
(9) #990381 (Brad M. of Washington)
(10) #990383 (Michael W. of Illinois)
(11) #990... (Richard A. of Oklahoma)
The remaining scopes are either in the hands of dedicated amateur astronomers (who don't know or care about their rarity and value), average citizens who bought one or received one as a kid, or hidden in basements and attics collecting layers of dust.
As time goes on more and more of these instruments will be reaching the marketplace. Previous owners are aging and their former scopes are now showing up at estate sales and auctions. Based on past statistics, about 2 or 3 new examples per year will become available for purchase. Since most everyone is now on the lookout for one, any and all existing scopes will disappear from the marketplace quite quickly.
...or the landfill.
Considering what I have seen senselessly destroyed in the past, one has to accept the fact that some of these scopes are really gone.
|
akman1955
Pooh-Bah
Reged: 09/07/09
Posts: 1081
Loc: Alaska, USA
|
|
 I sure do not have one and they seem too be very rare  hope you find more,John
--------------------
classic scopes unitrons/tasco/sears/san & strieffe...Too much!
|
habsburg8
scholastic sledgehammer
Reged: 07/07/05
Posts: 946
|
|
The photograph shows a picture of one of my Sears #6345 90mm equatorial refractors, serial #990152. It is not quite as good optically as my other scope marked serial #990112, but still is superb by any standards.
The heavy metal pier was purchased from an ad on Craigslist. The previous owner had his circa 1962 #10TE Tasco 3-inch f/16 Solarama mounted on it. Since the mounting bases with azimuth circles are identical on both the Sears #6345 and Tasco's #10TE, I simply switched the placement of the two scopes. It has worked out wonderfully and offers a very stable platform for the bigger 90mm refractor.
(The motor drive unit has been removed from the mounting and is being used as an upgrade on one of my Tasco #20TE 4-inch refractors.)
|
habsburg8
scholastic sledgehammer
Reged: 07/07/05
Posts: 946
|
|
A pair of replacement cradle rings from Parallax Instruments is highly recommended. They are an EXACT fit on the upper declination housing and remove the risk of scratching the tube. The original rings are a design flaw in the #6345 instrument, since they are so thin and flimsy. They also promote deep scratches and gouges in the white enamel finish. The pair of rings shown in my photograph of the #6345 make using this rare telescope much more enjoyable.
|
akman1955
Pooh-Bah
Reged: 09/07/09
Posts: 1081
Loc: Alaska, USA
|
|
 Very nice sear's telescope. From the look's of it I would say they didn't build very many. As expensive in price for the time's. What year's did they make this model and who made optic's. John
--------------------
classic scopes unitrons/tasco/sears/san & strieffe...Too much!
|
habsburg8
scholastic sledgehammer
Reged: 07/07/05
Posts: 946
|
|
This telescope was sold only during the years 1970-72. It was listed originally in the Sears, Roebuck & Co. catalog as #6345 for $499.95. By 1972, the remaining stock was sold off for a price of $299.95.
The custom refractor was made in Japan by Royal Astro Optical Industries Co. Ltd. There is some uncertainly as to the actual number of telescopes produced by that company; a former employee said around 600, but currently the highest serial number to emerge in the sequence has been #990383.
The main objective lens was probably made in-house by Royal Astro, but Horiguchi Optical Co. could have been the supplier.
|
habsburg8
scholastic sledgehammer
Reged: 07/07/05
Posts: 946
|
|
Richard:
Simpson-Sears located in Canada also sold many of these 90mm refractors. However, I think that the vast majority ended up in the United States with the greatest concentration occuring in California and the West Coast.
P.S.--Could you please provide our group with a high-resolution shot of your focuser plate? Make sure that the serial number can be easily read by everyone. I am trying to record all of these plate images for a Sears archive. Or please send it to me as an e-mail attachment.
|
woodsman
Pooh-Bah
Reged: 03/12/08
Posts: 1356
Loc: Colorado Springs, CO
|
|
Thanks for the info, I will do that sometime this weekend. Rich
--------------------
artisticwoods
C-14 Orange Tube, C-8, C-5, C-90 Astro Model, C8 Schmidt Camera 8" f1.5, C5.5 Schmidt Camera f1.65, SPI 42mm f/19 Refractor, Sears 90mm f/15.56 Ref, Sears 80mm f/15 Ref, Scope 60mm f/11.7, Sears 50mm f/12
Unitron Model 140 75mm/1200mm, Unitron model 128 60mm/900mm
|
habsburg8
scholastic sledgehammer
Reged: 07/07/05
Posts: 946
|
|
In previous discussions about the Sears 90mm refractor (circa 1970-72) some fairly extravagant claims have been made about its optical performance. The Model #6345 has been reported in the past to be superior to "Unitrons, other Royal refractors, and in some cases to Zeiss instrumentation."
Last night at home in the Willamette Valley of Oregon I put one of my Sears 90mm f/16 refractors, serial number 990152, through a series of stringent tests. Critical observations of both deep-sky objects and individual stars were made using a good selection of quality vintage oculars. The set consisted of these eyepieces: Nagler 7mm 'Circle R'; 10mm Clave Plossl; 13mm Tele Vue 'Circle R' Plossl--the best of that optical design in my collection; and a 40mm Tele Vue 'Circle R' Plossl.
After observing closely the set of test objects with the Sears 90mm achromatic refractor telescope, this is the conclusion that I finally reached:
YES, THE SEARS IS JUST ABOUT THE BEST THAT THE AMATEUR ASTRONOMER CAN GET OPTICALLY IN THE 90MM APERTURE CLASS. I STAND FIRMLY BY ANY PAST CLAIMS THAT MAY HAVE BEEN MADE ABOUT ITS STUNNING OPTICAL PERFORMANCE.
Tests were made with the first quarter moon setting in the western sky. It was relatively cold for this part of Oregon, with the temperature hovering around 37 or 38 degrees. There was some atmospheric turbulence, which did affect the steadiness of the star images when viewed through the main instrument. Toward the early morning hours fog moved into the area, blotting out the night sky.
The first photograph shows the Sears refractor used for the star testing and deep-sky observations in the late autumn night sky. It has been upgraded with a pair of cradle rings from Parallax Instruments, which help to prevent tube scratches (these are a perfect fit on the mounting head). There is also an added interchangeable adapter from another Royal Astro telescope. This minor upgrade allows the easy use of favorite 1.25-inch eyepieces and accessories.
|
habsburg8
scholastic sledgehammer
Reged: 07/07/05
Posts: 946
|
|
Another photograph of the Sears 90mm telescope used for critical deep-sky and star testing, serial number 990152.
|
habsburg8
scholastic sledgehammer
Reged: 07/07/05
Posts: 946
|
|
Before the evaluation begins, potential buyers of these rare classic instruments from Sears, Roebuck & Co. should be made aware of the following four important points:
*The optical quality, which is excellent or better, is very consistent from one telescope to another, but some are standout performers. I have never looked through a bad one.
*The images take a long time to settle down or reach thermal equilibrium when there is a large temperature differential. This undoubtedly is caused by the large amount of metal used in the Sears 90mm construction; the lens cell is oversized plus the main optical tube is solid steel. This can be annoying on occasions.
*The cradle rings need to be upgraded to thicker and better machined ones. I prefer those made by Parallax Instruments, since the dimensions are virtually identical and they fit directly onto the mounting head without any sort of modification.
*The wooden tripod needs to be replaced with either a heavier version or 'discarded' completely in favor of a tall metal pier.
|
habsburg8
scholastic sledgehammer
Reged: 07/07/05
Posts: 946
|
|
Now here's the deep-sky and star test evaluation:
Because of the long focal length and corresponding large image scale, the Sears 90mm performs wonderfully at low power. Star images are tack sharp across a beautifully flat field. Not a trace of chromatic aberration can be detected except on the brightest bluish-white objects. Image quality is very similar to my vintage Asahi Pentax 60mm alt-azimuth refractor, but of course the images are much brighter in the Sears 90mm scope.
**First test: Gamma Andromedae--An exquisite pair!!! No other words can describe the view of this double star through the Sears 90mm using the Clave 10mm and Tele Vue 13mm Plossls. Image quality is very similar to the renowned R61-D, albeit with much brighter and a tad sharper images.
**Second test: Gamma Arietis--A superb pair of pure white orbs! Textbook Airy disks and diffraction rings in the 7mm Nagler. The view of this double star system is very similar to one that I once had through a Unitron 4-inch f/15 refractor with great optics.
***Third test: Double Cluster in Perseus--Pinpoint stars strewn across an optically perfect field (Tele Vue 40mm Plossl). The sharpness of star images and clarity mimics that through a 94mm f/7 VERNONscope & Co. Brandon apochromatic refractor.
**Fourth test: Capella--Brilliant beacon of yellowish-white light! Very sharp and intense in the 7mm Nagler. At times this view of Auriga's brightest star reminds me of that through one of my other scopes, a Mayflower 76.2mm f/16 with superb optics by SYW.
The Sears 90mm has many advantages over other scopes in its aperture class. It is the best in the series of telescopes exported by Royal Astro Optical Industries Co., Ltd. The Tasco #7TE and #7TE-5 are good optical performers, but are limited by their small lens sizes of 2.4-inches. The Tasco #10TE 76.2mm f/16 has acceptable optics but the mounting is ill-designed. Sears' 76.2mm f/16 Discoverer has the same optical system and a slightly better designed mounting, but is still limited in aperture. Tasco's #20T can have good optics, but these are huge instruments that are really suitable for a home observatory. Unitron's 4-inch f/15 models are an alternative, but can be expensive.
IN MY OPINION, OTHER THAN UNITRON AND SWIFT THE SEARS 90MM IS THE BEST TELESCOPE IMPORTED FROM JAPAN DURING THE PAST ERA OF TELESCOPE SALES. IT IS THE BEST ALL-AROUND COMPROMISE BETWEEN APERTURE AND PORTABILITY, AND OF COURSE THE OPTICAL QUALITY IS SUPERB AND THE MECHANICAL DESIGN SOUND. IF YOU GREW UP WANTING A TASCO 7TE-5 AND LIKE THAT STYLE OF INSTRUMENT, THEN THE SEARS 90MM IS DEFINITELY FOR YOU.
|
Previous
Index
Next
Threaded
Edit
Reply
Quote
[Re: 