Vintage Celestron C90 Astro Telescope
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- Опубліковано 26 лис 2022
- If you've looked at my channel you'll know I like Maksutovs and old scopes, as well as more modern kit. In this video I look at my latest old scope, a Celestron C90 Astro from the 1970s. These scopes are fairly scarce and I couldn't find another video on YT, so here goes. Thanks for watching.
- Наука та технологія
I have a 40mm .965 japan made meade MA eyepiece, best way to get a bright low power image out of that scope. It is in NOS condition. It has a very narrow apparent field around 30 deg, but it uses the maximum possible field in .965.
There was also a wide angle 18mm .965, i think it was Koenig, it had a dome top, and might have come with later versions in the 80s
I’ve found a 0.965 to 1.25” hybrid diagonal to give me more options. They seem to quite difficult to buy these days.
The noted solar eclipse observer Fred Espenak used an orange tube C90 spotter on an eq mount for his world travels with outstanding photo results.
ya those were cute small scopes good for land viewing too
Thats Sweet,Youve Got Me Liking These Little Things😂Im Curious To See How It Is Optically.I Still Love Mine,From Not Sure How Many Years Ago Now,lol..A Few..Ive Paired Mine With The Exos Nano Eq3 Mount,For A Totally Powerless Grab and Go Set Up,Its Perfect For That Thing.Great Video,I Look Forward To An Update,God Bless and Clear Skies❤️🙏🏼🔭✨🌏
Thanks, It is a nice thing! l’ll add an update when I’ve used it more. I could do with finding an LAR (unlikely I know) or a hybrid diagonal but until then I’ll try a camera at prime focus. The 18mm has given sharp lunar views.
Definitely something I'd try for planetary imaging first. Mars being in opposition might be a good candidate, especially if you can get an adapter that works with the rest of your photography kit!
Yes, I'll give it a try if I get some steady seeing (and an adapter!)
I've got three of these wonderful little scopes. They are heavy though, so the fork mount, wedge, and tripod are a definite improvement over the spotting scope model.
Yes they are solid scopes, built to last!
@@JenhamsAstro Yes, these are sweet little rigs to use. I noticed you didn't have the counterweight which mounts opposite the single tine fork. The scope won't balance on the mount without it. The counterweights stack if you have more accessories (which I do).
@@rodneyhelt9215 You’re right, mine didn’t come with the weights.
@@JenhamsAstro The weights are easily misplaced or lost when not in use. Celestron provided the same weights with their C5's and C8's, so I have options when I need one. The original C90 orange-tube model is extremely ruggedly built which makes it a perfect public outreach scope, especially for school outings. The kids can't destroy it!
@@rodneyhelt9215 Is it possible to replace the C90 with a different scope on the mount?
I've seen them and didn't realize that they focused like that.You can probably still get .965" eyepieces but they tend to be narrow field of view and low quality.I think that all .965 eyepieces would be second hand as I don't think that any are made now?You can get adapters for 1.25" but sometimes .965 telescopes won't focus with the adapters.
Hi Kevan. Yes, I’ve got a Baader adapter but my C90 won’t focus using it and 1.25” kit which is frustrating. To be fair the standard 18mm 0.965” EP is sharp, but not great in terms of eye relief or FOV. New video imminent with my attempt at AP with the scope! Graham
@@JenhamsAstro try buying a cheap .965 to 1.25 adapter, the Baader one is too pricey to potentially destroy, and sawing off a 1/4 of it and see if that works.Better still enjoy the quirkiness of using .965"eyepieces and telescopes in a 1.25"(occasionally 2" too) world! Apparently they did make some high quality 965"eyepieces.
Pop it on an old Tasco StarGuide - Baby Nexstar mount
Where are you acquiring these old telescopes from Graham? You always did have a soft spot for the C90.
Yes, I am a big fan! In this case I placed a wanted ad on Astrobuysell and was fortunate enough to find an owner with a spare scope.
You've had quite a few telescopes over the years. Ever think of doing a video on your favourites and what makes them so?
That’s a good idea, I’ll have a think about it. I’ve sold a lot of scopes as well as buying them, and made a few mistakes in doing so. Maybe a personal top 10?
@@JenhamsAstro Sure! Maybe lay out the kind of conditions you view/capture under first for context to understand how each scope fits with your lifestyle?
I’ve had one of these scopes for many years and recently pulled it out again. I’m missing the part that screws into the star diagonal on the outside. It holds the .965” 18mm Kellner Lens and/or the Extender. They slide into this black metal part for viewing. Does anyone know where I can get this part?
Sorry I don't have a good source other than looking for a replacement diagonal on eBay etc.
I own one of these telescopes. I bought it new in 1983.
Do you still use it? So far I'm happy with the quality of the views but the 0.965" accesories are not ideal, and it seems that hybrid diagonals are hard to come by.
@@JenhamsAstro I use it a bit, but I have many scopes! Recently, I renovated the interior by adding flocking paper inside the eyepiece tube and blackening some shiny areas. I feel this improved the contrast. I found a hybrid diagonal so I can use my 1.25” eyepieces. I wish there were a finer focusser. The telescope has a solid build and I believe mine was “made in USA” before they moved manufacturing to China. The instructions I have for the Barlow are quite different. I need to look into your method.
@@JenhamsAstrobest to just use a 1.25 diagonal and one of those .965 to 1.25 cup adapters. Though a hybrid diagonal might have a tad less vignetting if trying to use 32 and 40 plossls.
China didn't come into play until much later, but the synta and bosma 90mm maks which look nothing like the old c90 did come along before celestron SCT production moved to China in the mid 2000s. The c90 of this style was never made in china.
Celestrons c90 spotter was made by bosma prior to the 2004ish synta buyout, and then a few years later they switched to the synta mak, same as skywatcher and orion maks, which in my opinion and many others' is an improvement.
Many would go as far to say the synta 90mm mak (unless you get a bad one) is a better performer than the old c90. (Not counting the old 500mm fl telephoto lens/spotting scope 90mm mak that synta made in the 80s).
If it's a synchronous motor set up for USA 110V, it'll also expect to run at 60Hz, not 50Hz so the tracking will not be as accurate.
Hi David. Yes it is expecting 60Hz. I haven’t decided whether to buy a transformer or not. Based on my (240V) C5 I expect the C90 will get more use on another mount than on its fork, so I may go down that path. The C90 also has some friction somewhere in the base when I turn it, which I think would require a puller tool to disassemble and resolve.
Pretty good for a Questar clone.
The motor wouldn’t even be that accurate now that the net is not regulated for clocks anymore. The cycles are all over the place.
You bought this in the UK or EU?
There is probably a thing such as a cycle correcting PSU. Never looked though.
@@Frisenette I bought it second hand in the UK, although it’s a US model.
Great video. 😀
I have qouestion.
I get to me my first telescope but i do not now how to zoom.
If you can help me i will be really thankful.
You normally use different eyepieces to give different magnification. Alternatively there are some zoom eyepieces available, often providing a 8 to 24mm range of focal length.
@@JenhamsAstro thank you so much
Anyone interested in buying one? We have one we’re ready to get rid of.
I probably shouldn't add another old scope to the herd but I can't resist asking for a few details! If you have an original Large Accessory Ring to allow use of 1.25" eyepieces then that would be tempting - these are very hard to find in the UK.