This auction is for a 1988 Celestron (Torrance, CA, USA) C90 and C5 black cast aluminum 5x24/8x20 finder scope mounting brackets system. It will come complete with all (3) original #10-24 brass setscrews for aligning the finder; these screws being the desirable, nylon-tip variants, which will protect the paint on your vintage finder. Also included for your convenience, the original, (2) chrome-plated brass #8-32 philips dome screws for mounting these brackets to your vintage, USA-years C90 or C5.
Now, this finder bracket assembly is very special in that it is the rare elongated model. Almost always these finder brackets have (2) perfectly circular holes for mounting to the C90/C5 optical tube. As such, in these variants, they will ONLY work on the C90/C5 models of pre-1999 years; they cannot mount to a Meade 4-inch schmidt or the 97 Series Spotters because although they share literally the same finder and same cast aluminum bracket mount, their bolt patterns are not the same.
A vintage Meade small cassegrain has a finder bracket bolt pattern with a 0.90-inch spread.
A vintage Celestron small cassegrain has a finder bracket bolt pattern with a 1.08-inch spread.
In most cases, this means a Meade 5x24/5x21 finder bracket cannot mount to any Celestron C90 or C5. And a Celestron 5x24/8x20 finder bracket cannot mount to any Meade 97 Series maksutov or 102mm schmidt.
But because the base holes on this Celestron small finder bracket mount are oval in form, they IT CAN cross over to a Meade; yes!
This bracket will hold ANY finder scope in the 20mm to 24mm aperture size; this includes both the orange and black Celestron (Vixen and Carton Optical of Japan) 5x24 finders and the 8x20 black finders (Taiwan, Korea, and China). It will also hold the older Meade Model 541 5x24 finders (2045) and the rarer 5x21 finders (97 Series maksutovs).
The Meade ETX-dedicated 8x21 erect image finder should work no issue with this bracket system. However, the Meade Model 825 8x25 right angle finder will not work because it is a tight fit and the finder is barely long enough to contact the necessary area within the rings. That finder will only work in a single bracket mount.
The Takahashi 5x25 finder will not fit; it is too wide.
For steady results, a small, rubber O-ring is usually needed to keep alignment spot on during transportation. You can also use electrical tape or a rubber band on the end of your finder-in-use; a safe option which will not harm the paint on the finder.
These black-colored aluminum brackets were stock on ALL C90 Spotters (1984-1999), which would have been the black gloss and Rubber Armored models, and with the very rare 4th generation C5 Astro (1985) and later on, all 5th generation C5 models (1992-1999).
If going for absolute stock in color is not a concern, these finder brackets will fit ALL C5s from 1971-1999 and ALL C90 Spotters from 1978-1999.
To the experienced C90 collector, they will remember there are (3) generations of the black cast aluminum 8x20/5x24 aluminum finder brackets; those that came with brass set screws, then the brass setscrews with the malachite-colored nylon tips, and finally the post-1995 brackets, which are the exact same color and texture, but came with domed, black nylon setscrews. Both of these bracket variants came on both corresponding years C90s and C5s.
The 5x24 brackets will not work on any Meade ETX-90, 105, or 125 because their finder scope brackets mounting pattern will not match. ETX finders mount via a single tiny allen bolt on the rear face of the mirror housing.
Also, this bracket mount will not work with any of the Chinese-sourced C90s because they used a Vixen-style dovetail quick-release saddle for their finders. It will not work with any Celestron Nexstar 5 because for virtually the same reasons (or in the case of the 1st gen Nexstar 5, it has a different bolt pattern for the non-quick release red dot finder base).
And, again, because this is the rarer, elongated holes model 5x24 finder bracket mount, it will fit to the following Meade small cassegrains:
* 1022
* 107D
* 1037
* 2040
* 2045
* 2045S
* 2045D
* 97E
* 97D
* 97ER
To the avid Meade collector: these brackets will not fully color match your vintage Meade telescope because though they came with black, dual brackets also, the paint on their brackets was always smooth and never came in spackle texture. To the inexperienced, however, these will appear stock.
Bolt pattern at narrowest using #8-32 hardware: 0.87-inch separation
Bolt pattern at widest using #8-32 hardware: 1.20-inch separation.
Inside diameter of the rings are 1.10-inches. If using a non-Celestron brand 5x to 8x finder, make sure its tube diameter WILL BE SMALLER than this measurement.
It is important to remember that this finder bracket system is a LOW-PROFILE model; meaning it will position the finder scope only slightly above the optical tube. This idea works with cassegrains (and some refractors) because your face will be positioned behind the end of the telescope in which the actual telescope tube will not interfere with clearance for your eyes to meet the finder scope eyepiece. However, if you use this bracket system on a reflector, if you are using a non-angled finder scope, your cheek bones will bump into the optical tube and your eye will not be able to reach the finder scope eyepiece.
Made of solid cast aluminum with brass setscrews.
Weighs 1.3 ounces with setscrews
Weighs 0.7 ounces without setscrews
This auction ad was completely, organically written by Veradale Mobile Observatory, not an A.I. software device; an actual honest-to-goodness, real human with over 20 years experience with now over 1000 telescopes made from today and all the way back to 1948.
Packed with great care.