$200 10" Coulter Dob VS $10,000 Astro Physics ultimate APO refractor - Ultimate Telescope Smackdown! 

Coulter's 10" and the 13,1" equivalent I think have the best Dobson construction, you can sit very comfortable and look through the eyepiece.

I own an astrophysics gt130 and had occasion on one steady night to compare its views of Jupiter with two skywatcher dobs the cost about a grand each. One was 10 in the other was 12 in. They have been upgraded with moonlight focusers and better bearings. The gt130 was putting out terrific views. They cleaned the clock of my 5-in refractor. Better banding detail and richer colors. But the truth is you don't get a refractor to have Superior detail to an 8 or 10 in or 12 in dob. You get it because spending time with a top-notch refractor is totally awesome. You adjust your observing program to the aperture that you take to the field. When you are new to observing you might think a view of m13 and Hercules at 256 x is the cats meow. But after you've been at it for some years you may develop an appreciation for something like NGC 6712 in the Milky Way at 20 x.

I call B.S. on the the Dob having a double image. You need a parabolic corrector for that t fast scope. My 8” dob is crystal clear with amazing detail even with cheap eyepieces. Also collimation helps. If that’s all you get with a premium 120 APO, you just saved me the trouble. Thanks. This Apo craze is like extreme Apple products.

I've had my 130 AP next to a WO 132 looking at Jupiter, I can see a real difference on planet details. AP was little bit better. But a 140 Tec was the same. Live in Utah.

I didn't know these Coulters even existed I guess you don't want these to get wet. Thanks for the video.

The early Coulters (pre Dob) had superb optics. I had one I bought in 1977. I was a 14.25: f/5. The optics was rated -+1/25 wave and I believe it was. I build the rest of the OTA around the Coulter primary and secondary. Novak spider and sec. holder, Novak mirror cell. The tube was a Parks fiberglass. The mount was a Cave Astrola which may have been one of the last ones as Mr. Cave had health problems with competition from Meade delivering the final blow. I had a view of Saturn through it which I have not forgotten to this day.

Those old coulters are something else haha, I have an old 8" f/4.5... complete with futuristic plumbing parts focuser and cutting edge particle board duct tape mirror cell 😂. I rescued it out of the trash! In near perfect shape too, just very dusty . At first, yeah crap optics... but after some tinkering it came to life. The secondary is collimatable somewhat.. after loosening and prying on the spider bar and the mirror tilt, i managed to get it dead on and tightened back down. I also drilled some holes in the "mirror cell" and redid the duct tape and felt pads and it actually drastically improved the image. It takes about a million years to cool and I definitely wouldn't say it rivals my APOs, but it still performs admirably|on the moon and planets, up passed 200x. Using a stop down mask sharpens thing up even more.

that first minute view of the lake and mountains... stunning!

When Newtonian mirrors are made, if they are not cooled properly, they can develop fractal stresses (basically, cracks that you don't see) which have the effect of giving your mirror two or more planes. To ship a mirror with this defect indicates very bad quality control. I know because I had such a mirror, from the late 1960s. It delivered 3 images. If you looked at Jupiter there was the "bright" image and two ghosts. The stresses were invisible to the eye and to the touch but they looked like canyons on a Foucault tester. I would suggest that you get that Coulter mirror to a Foucault tester as fast as you can. If it has this cooling defect it is not salvageable. This is the only time I've seen multiple images from a well collimated Newtonian. It wasn't in the eyepieces (which are Pentax and don't do that). I've provided a link to the Foucault test posted on Cloudy Nights. To find a Foucault tester look for an amateur telescope maker club (or a regular astronomy club) near you. Anyhow Coulter was not known, as it became "big" in the 1980s, for highest quality manufacturing. It is quite possible that it shipped a mirror with a similar defect. www.cloudynights.com/topic/507619-cave-or-not-cave-that-is-the-question/?p=6712955

Can you do a review on the astronomy chair used in the vid?

Another entertaining video. Keep them coming. Thumbs up Vlad. I have watched all of them, even if some material seems redundant and repetitious for me I still manage to gleen something worthwhile. =)

Very cool. Just saw the video on filters too that was great as well.

Vlad, I got a kick out of how you use your Losmandy G11 like I do. I don't use the GOTO functions at all, mainly because I've never figured out how to get Gemini 1 to work. I just polar align, turn it on, push it to where I want it to go and let it track. I've recently upgraded my mount to Gemini 2 and I hope it is more user friendly. My 5" APO is an f/7 Stellarvue and I really like it.

I love your videos but this one is an epic fail. A 10 inch dobsonian is a fine astronomical instrument but the one you tested is a POS!

I did enjoy your video, but I don't believe it was a fair comparison. For detail a good refractor will always beat a Dobsonian scope for image quality regardless of the price. I have this scope and a newer Celestron 8" SCT, and there is also no comparison there. That Dob is approximately 40 years old. I bought one new back in 1982, and I still have it as I mentioned. The ones from that time frame were blue colored like yours, the ones they made around the mid 1980s were red if I recall correctly. The tube is mad of Sono tube which is what they use to form cement pillars and are very sturdy. New they were $299.00. The focal ration is F4.5, which I am guessing is faster than the refractor you had in your video, so that would probably explain the difference in image definition, but I am guessing since I don't know the specs on your refractor. You said several times that you can not collimate that scope. That is incorrect. The are five screws on the bottom door that mounts the mirror. Two hold the door in place when you load your mirror, and three screws on the bottom door in a roughly triangular pattern are what you use to collimate the mirror. There should also be fuzzy circular piece of material on the edge of the mirror, that you line up with the same sort of spot on the inner surface of the door. Once you line up the spot on the mirror with the spot on the door, you can adjust those three screws to adjust collimation. I know its not as easy to collimate as there is no little collimation circle on the mirror like todays mirrors, but I don't believe any Newtonian reflector had those circles back in the day. I still have my instruction manual that came with mine that describes the collimation process. I would be happy to send you a copy of the manual if you are interested. Keep the good stuff coming. I enjoy them very much.

With all the scopes and accessories you have.... How do you NOT own a phone adapter? 😂😂 Awesome video however. Fun comparison.

Could be a cooling issue with the dobsonian, my 14inch takes quite a long time to cool

do you think your conclusions would be the same if you compared the refractor to a comparable size sct or mak?

I know you said the secondary mirror couldn't be columnated, but what about the primary mirror? My first ever scope (Apertura 8D8) should arrive next week! I'm so excited!!! Hope it produces clearer images than the $200 scope you just got, lol BTW, you mentioned in one of your other video you live in the NW, anywhere close to Seattle? Like your videos btw :)

The views of the moon you showed were not well done. Do your homework and try harder next time. Beautiful location though. Could have been much better.

Could you compare a modern 10 inch Dob say an Orion, or Apertura to the Astro Physics? I have a 10" Zhumell (GSO) and it performs much better than the Coulter.

Just grabbed that dob for $100

Actually the timex keeps better time than a rolex

Ok like am gonna, like actually like check it out.

Only just a minuscule difference really.

Collimation makes all the difference. Is sad its "not" collimate it