Celestron C90 Review

[@Deltan1967]

I bought my C90 as a spotting scope for taking to the range, and also for taking pictures of the abundant and varied wildlife here in Australia. This 'scope performs these tasks admirably. It's only now that I am working out that I can use this for taking pictures of the planets too? Awesome. I understand that from an Astronomer's perspective that the C90 leaves a lot to be desired, but from my perspective, this gets me better results than some very expensive glass I've seen around on dedicated spotters.

[@EarthtoSpaceScience]

It is one of the very best “bang for your buck” telescopes out there. For the price it performs amazing. Obviously you can spend $3,000 and get a much better telescope, just like anything else. But for the price it does well. You can certainly get nice views of the planets with it when the atmosphere is steady.

[@anvikshiki]

Enjoy your videos, Steve. This c90 was actually my first scope, and I used it to learn how to do planetary photography for a year and a half before upgrading. Of course the aperture limits its resolving power. But, when I put it on top of an AVX, and added a 2.5x Powermate with a cut filter, an ADC and an ASI224mc onto it, the focal length helped to produce some images of the planets that were surprisingly decent. Of course I grew tired of the limitations and eventually got an SCT 9.25 and am now searching for a first refractor for deep sky. But I have to say the c90 was a highly usable scope to learn on, so I'm kind of grateful I started on it. Thanks again for all your videos, and especially the one on the Baader flip mirror, ehich I love using!

[@billtracy8865]

Thank you for a good honest review. Great coverage of both faults and positive features.

[@Gazereths1234]

The Omegon II mini Dobsonian mount works reasonably well with this for about £50, great for tabletop/windowsill work. I don't like using it on a photography tripod. Mini dob works nice and you can still use the 45 prism when sitting at a windowsill for near to the horizon objects, though a 90 degree is really a must as well for closer to zenith.

[@naishkiter10]

I’m trying to decide between this scope or the Celestron Ultima 100mm for city viewing.. any input or perhaps another choice would be greatly appreciated.

[@EarthtoSpaceScience]

I don’t have any experience with the other scope you mentioned. The C90 is super portable but limited in aperture. An 80mm refractor with ED glass will outperform it but will also be longer and less portable. If you can swing a C5, which is about the same length but larger diameter that will perform nicely for you. The 100mm one might do nicely as well. Larger aperture will of course almost always do better but then becomes less portable and then maybe you don’t want to use it so it is never an easy decision. I’ve gone through a lot of different scopes because of that and keep trying our new ones (selling the old ones).

[@jameswilkinson259]

Hi Steve, good information! Question: Do you know if the dovetail rail is removable?

[@jimfischer4703]

Thank you

[@charleshetrick3152]

Looking at this for spotting 1/4” holes at 600 yards at the shooting range. I’d assume adding a 12 or even 7 mm eye piece would be a good plan?

[@EarthtoSpaceScience]

7mm is about the limit this scope can handle and may be a little beyond it. You will need brighter conditions for it to work well since the exit pupil of the eyepiece with that focal length scope will be less than 0.5 mm and so the image could be too dim if indoors. Will work better out doors in sunshine though. What might work really well is an 8-24 zoom lens so you can adjust to the magnification for conditions.

[@alexj9111]

Just ordered a C90 Mak online, but just read a review about it having a major alignment problem. I dont know if I should cancel the order, or just take my chances? Thanks.

[@EarthtoSpaceScience]

I don't think that is common, but unlike an SCT, you can't easily fix it if you have one and basically have to return it if the collimation is way off. Make sure you can easily return the scope from wherever you buy it (that is true for any scope purchase, really). Normally they are pretty good, but with the lower-priced telescopes like the C90 there is going to be a little less quality control than on the more expensive telescope.

[@alexj9111]

@@EarthtoSpaceScience Thanks.

[@Thestripper1]

0:57 I know this is difficult to answer or to show in a video but, what can I expect to see with my eye when looking through the telescope at saturn for example? Will that view have/or feel like it has higher resolution than these photographs?

[@EarthtoSpaceScience]

Views of planets vary enormously over time. If the telescope isn’t fully equilibrated with the outside temperature, heat plumes in the scope will interfere with the image. If the air outside isn’t steady, you will also get a wobbly image that doesn’t look great. If the planet is anywhere near the horizon it won’t look great. The quality of the eyepieces will make a difference too. That telescope can give really nice views of Saturn. But, you might take it out 20 times to look at Saturn and it will look like trash 10 times, ok 5 times, pretty good 4 times and great once. Just the way it is with the atmosphere unless you live in an area with very steady air. Also, it depends how far a planet is from opposition. During the weeks each year when Jupiter or Saturn are near opposition (directly opposite the sun from our perspective and highest in the sky at midnight) we are also closer to them than at other times of the year and so they appear much larger and so the views are much better. Both Saturn and Jupiter were at opposition during the late summer I think and are pretty far past at this point so the views now aren’t as good as they were a few months ago. Plus, the atmosphere is usually much less steady during the winter than during the summer. The views will be best again during late summer and fall 2023. But, you can still get nice views now when the air is steady. The bottom line is don’t take one look and decide it is useless. The more often you look the more often you catch good views.

[@Thestripper1]

@@EarthtoSpaceScience Thanks. My question was really more what can I expect to experience with my eye, rather than taking photos. There's so many astro photographers that I don't feel a need to take any pictures to impress anyone. Such pictures can be found by a simple google search. I am interested in observing and experiencing that so my question was really if those pictures are comparable to what you see looking through the telescope or are those multiple exposure enchanced and what not?

[@krash3x]

@@Thestripper1 No it’s not. These images are done by stacking. This increases the color saturation, brightness, and contrast to compensate for a lower aperture size.

[@alexj9111]

I can't decide on getting the celestron C90, or a cheaper smaller spotting scope with 75 times magnification. Would a spotting scope enable me to see the planets just as well?, or would the celestron be the better choice?

[@PafMedic]

Ive Had This Little Scope As A Grab and Go For Over A Year,and Yes,Even Tho They Are A Bit Smaller,This Little Thing Has Beautiful Optics,and Ill Compare It Up To My 6se,I Love This Thing,Comes With A Robust Think Its A 32mm Plossl EP,And Yeah,Youll Need A 90 deg Diagonal For Celestial Viewing,And Its Great For Solar System,and Brighter Deep Sky Imaging With Either Your Canon Or A Cheaper Planetary Camera..He Didnt Show What This Can Do,Go To Jenhams Astro,Thats Who I Watched When I Was Deciding For This,He Has Both Celestial,and Terristial Reviews,Deep Sky Objecs,Best Ive Seen On This,And Till This Video,I Thought I Had Watched Them All,And He’s Right About EP,It Just Comes With 1,I Dont Have Any Videos,😂😂I Havent Had A Clear Sky In Over A Year,I Gave Up Months Ago,lol..Good Luck To You,Clear Skies,If I Can Answer Any Questions I’d Be More Than Happy Too.❤️🙏🏻✨🔭🌏

[@alexj9111]

@@PafMedic Thanks, i'll consider getting one. Cant wait for a clear night.😁

[@PafMedic]

@@alexj9111 ,Sweet,And Im Not Sure What They Are Now,But Prices In The Astro World Has Sky Rocketed Since Covid,Pouring Here Still Im In NWPA

[@Ask_to_ask]

hi sir please help me, i need to choose between.. sky watcher 102 mak , 90 mak and c90.. iam not talking about the price, but i just want to know which one have the best quality. I heard the c90 had a glaring funnel ( The baffle tube is shiny ) that couse contrast issues. did sky watcher scope also had the same glaring problem ? hope you understand my english. and pls let me know which one you prefer. tqvm

[@EarthtoSpaceScience]

Yes, the c90 has some reflection issues though you can solve those by adding some flocking to the tube. Bigger is usually going to be better in terms of image for the same type of scope, and so the 102 is going to show more detail on planets and gather a little more light overall. Of course you give up a little portability. The difference between the 102 and 90 isn’t nearly as much as between the 102 and 127, however.

[@Ask_to_ask]

@@EarthtoSpaceScience tq sir

[@PafMedic]

@@Ask_to_ask ,Light Is Bouncing Around Inside Of The Scope.A Paper Type..Called Flocking Paper With Help With This,Kind Of Like A Cardboard Tube Down Over Your Scope,Lined With Felt Or Something Like That,Or Just Buy A Dew Shield For And Its Gone.

[@Ask_to_ask]

@@PafMedic thx

[@Meme-ke6xx]

Is the Amazon Basics 60-Inch Lightweight Tripod with Bag compatible with the Celestron C90 because I’m afraid of buying the wrong mount and if it’s not compatible which ones would you recommend that are under $100

[@EarthtoSpaceScience]

It should mount on any photo tripod with a 1/4” bolt but I don’t know how stable that tripod will be. It will probably be fine for terrestrial use, at a gun range, or for lower power astronomy use, but typically those types of tripods aren’t smooth enough to use at high powers since once you get above 150x stars and planets zip across the eyepiece pretty fast and it can be hard to keep them in the eyepiece without slow motion controls or a really smooth pan head of some type. Also, some of these can shake a lot when used with the legs extended at high powers. Again, I’ve never used one of these so I can’t really say and it depends on what your use case is.

[@Meme-ke6xx]

@@EarthtoSpaceScience oh okay I see what you mean thank you for replying

[@kishascape]

@@Meme-ke6xx is fine tripod. I use SunPak model that’s basically similar, they all come from same factory. Is good for spotting scope use.

[@starsandnightvision]

Would this work well with a Night Vision camera attached to it?

[@EarthtoSpaceScience]

I don’t think it would be a good option because it is a long focal length. Night vision cameras works better with shorter focal length scopes under f/7.

[@kishascape]

The f stop is about right for spotting scope actually. It pulls brighter image than 80mm refractor spotting scope and no chromatic aberrations either. IDK why astronomy people are always so out of touch.

[@bigg9042]

to much hate about a good scope

[@EarthtoSpaceScience]

I like it as a quick look and travel scope. It does great in that role since you can carry it around super easy, goes in a backpack without thinking much about it, and produces pretty nice images. It is great for those 5-10 minute viewing sessions before work in the morning when you don’t have time to bring out a bigger scope.

[@Sarimae23]

@@EarthtoSpaceScience its lightweight, thats what i need for an LCM mount :)

[@EarthtoSpaceScience]

​@@Sarimae23 I continue to take this scope with me everywhere. It is super easy to just take a good compact photo/video tripod and toss this scope in your backpack or small carry on bag.

[@Sarimae23]

@@EarthtoSpaceScience maybe i can get one for 80 bucks toimorrew.. sounds like a steal

[@PafMedic]

@@Sarimae23 ,Not In Todays Market

[@stevejosrph6065]

Your Review was not good at all you only compaired it to others that's not a review its a comparison ... We didn't expect it to be as good as the better models that's obvious we just wanted a simple review ....

[@EarthtoSpaceScience]

I’ll try to do a better job next to around.

[@PafMedic]

I Might Be Able To Help You,If Your Still Around,Ive Had This For A Good 2 Years Now.For Viewing and Imaging,All Celestial.