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Something for nothing: Celestron C90

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#26 jrbarnett

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Posted 18 January 2012 - 04:18 PM

Welcome Rahul.

Now that I've had it out for three sessions, overall I remain impressed with the value and performance for the money. One downside that has come to light is less than perfect baffling and/or tube blackening. When observing the belt region in Orion, for example, and placing any of the intense blue-white sword stars just outside of the FOV, you get some arced glare in the field of view. I suspect that the interior of the OTA itself is not matte black enough. At some future point I may play around with flocking or repainting the interior to see if it eliminates this condition. Other than that, it's been a nice performer.

Regards,

Jim

#27 michalh

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Posted 18 January 2012 - 09:29 PM

First light! I had a brief 1/2 hour of thin clouds (about as good as it gets here in the winter) and was very pleased. Nice views of Jupiter's bands despite looking through the clouds with the 32mm eyepiece, then dropped in my 13mm Nagler. High power views are noticeably dimmer than in my 8", but not bad. Can't wait for better viewing conditions. Before sunset I made a solar film filter utilizing a DVD stack cover and watched sunspots. Also tried the bino-viewer and had no problem reaching focus with it in a 90 degree diagonal. I can tell this is going to be a favorite with me; heck, the thing is so inexpensive I don't feel paranoid about leaving it out to reach equilibrium while I'm staying warm in the house. I left the 8" home last vacation because I just didn't feel safe leaving it in the van. This little guy will go everywhere with me.

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#28 jrbarnett

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Posted 18 January 2012 - 11:26 PM

Looking good!

:grin:

- Jim

#29 mattyfatz

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Posted 19 January 2012 - 11:12 AM

Well Jim ....
It appears you got a heck of a deal. I haven't seen them being sold for $160 anywhere.... Not that I need another scope mind you.. Just looking around
:undecided: :undecided: :ohmy:

#30 jrbarnett

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Posted 19 January 2012 - 11:22 AM

Still available bundled with the tripod for $160:

http://www.opticspla...-with-trip.html

Seriously, can you afford NOT to have a $160 3.5" scope with a lifetime limited warranty? :grin:

- Jim

#31 michalh

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Posted 19 January 2012 - 12:55 PM

When I think of the kids who received a suspect refractor for Christmas and could have gotten this...ugh. It seems like a great beginner scope since the objects most starters like to look at are bright - Moon, planets, daytime objects. Very lightweight and durable as well. And yes, it is still available this morning; widely available if you don't care about getting another tripod.

#32 Johnny G

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Posted 25 January 2012 - 05:38 PM

I want to get a compression visual back for my C90 if anybody has any thoughts on where to find one let me know.

Thanks, John

#33 jrbarnett

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Posted 25 January 2012 - 06:51 PM

John:

Here's how I would go about it.

First, I would buy one of these:

http://www.adorama.com/ONMTSCTR.html

That should allow you to use a standard SCT visual back and accessories.

I would then get one of these:

http://www.opticspla...ct-adapter.html

Shorter is probably better.

Lastly I would add a 2" to 1.25" compression adapter like this one:

http://agenaastro.co...ce-adapter.html

Presto, for $100, you've added a 1.25" compression rear to your $150 scope. :grin:

It's probably cheaper just to buy a spare diagonal nosepiece and use the one that gets chewed to ribbons with the MCT and use the pristine one for scopes with a rear compression fitting. Or even simpler; buy a second diagonal - a sacrificial one for the MCT with its pointy little set screws.

Regards,

Jim

#34 Johnny G

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Posted 26 January 2012 - 06:14 PM

Hi Jim,

Are you sure that Orion adapter will fit on the C90

john

#35 jrbarnett

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Posted 26 January 2012 - 07:28 PM

"The adapter ring threads into the rear cell of any Orion Maksutov-Cassegrain telescope and provides male SCT threads just like those on the rear cells of Orion, Celestron, and Meade Schmidt-Cassegrain telescopes. The threads are compatible with all thread-on SCT accessories, including visual backs, 2" SCT diagonals, and common SCT camera adapters."

http://www.telescope.../40/p/52067.uts

That's what Orion says. By "any" Orion MCT I assume that includes Orion's 90mm MCT.

If you look closely at the rear of the Orion 90mm MCT you'll see that the visual back is the same as the one on our C90s.

Orion:

http://www.telescope...c/14/p/9820.uts

C90:

http://images1.optic...pe-52268-03.jpg

So I'm 99% sure it will work. Celestron is owned by Synta and all of Orion's MCTs are manufactured by Synta.

Regards,

Jim

#36 jrbarnett

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Posted 26 January 2012 - 07:30 PM

Y'all must be buying up the C90 + tripod bundles. The price has gone up from $159 to $179.

http://www.opticspla...-with-trip.html

That's still a better deal than the OTA without the tripod which is still $209 at the same site.

Regards,

Jim

#37 Johnny G

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Posted 26 January 2012 - 10:05 PM

I'll give it a shot I think it should be fine. Thanks Jim.
John

#38 Tony Gee

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Posted 26 January 2012 - 10:47 PM

Thanks Jim.

Just ordered one: Celestron 39-100x90mm Maksutov Angled Spotting Scope w/Tripod 52268-OP - $174.95. Even though it was a few bucks more than $160.00, I couldn't resist the offer. It even comes with 2 eyepieces and the image erect 45 deg. diagonal.

Tony

#39 jrbarnett

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Posted 26 January 2012 - 11:10 PM

Tony:

I think you'll be pleased. I had mine out before our current rainy spell over a few consecutive nights and it is a fine scope. M81, M82 and M1 were quite nice even under suburban skies. The Trapezium was excellent as was Jupiter. Even the stubby little 8x20 finder works adequately. The only negative I think you'll want to address is the lack of a dew shade. Not so much for dew suppression (though depending on your location that might matter) but to prevent stray light from illuminating the interior tube walls and putting arcs in the field of view. The interior isn't perfectly flat black and a bright light source off axis, just out of the field of view (like Jupiter or the Moon) will generate some stray reflections in the eyepiece. Other than that the scope performs similarly to an 80-85mm refractor.

Enjoy!

Regards,

Jim

#40 Starlon

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Posted 27 January 2012 - 12:03 AM

Just picked up this little gem: http://www.celestron...-telescope.html Fantastic.. :jump:

I still cannot believe it..! The deal - and, you'll have to read what this thing can do. I almost ordered another - they are discontinuing it. For $179 you get the whole package. Still can't believe it!! So cool & can do so much.

#41 XyrcesFenol

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Posted 27 January 2012 - 05:11 AM

I have a C90 and wants to know if someone tried to upgrade the diagonal from the supplied prism to a real star diagonal.

Does it make sense to go for a William optics 1.25 Dielectric diagonal?

This could of course be inside my head, or due to better seeing that night, but:
If I remove the 45 degree std prism and instead just put the ocular straight in the tube everything is of course reverse and upside down, but I experience much better contrast on the moon, persieved sharpness and more pin point stars. Moons of Jupiter feels better too. Some very tiny yellow coloring is also gone.

Happy to hear your thoughts.
Per-Erik

#42 n1toga

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Posted 27 January 2012 - 06:02 AM

Just picked up this little gem: http://www.celestron...-telescope.html Fantastic.. :jump:

I still cannot believe it..! The deal - and, you'll have to read what this thing can do. I almost ordered another - they are discontinuing it. For $179 you get the whole package. Still can't believe it!! So cool & can do so much.

Yeah Tell me about it, pulled the trigger on the same package about a week back thanks all to Jim....but have to wait till march to put my eyes on it as it has to be hand carried to India from the States.
Rahul

My devious plan is to try and plug my Nexstar SLT controller into the mount and see if it'll go-to....muhhuahhahahahaha!

#43 Binojunky

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Posted 27 January 2012 - 06:17 AM

I tried both a Williams diagonal and a very nice Celestron diagonal, I ended up keeping the Celestron diagonal in the case with the C90, its an older made in Japan one from Vixen, at one time you could also get it with the Orion logo one it. Televue used to sell it as well with the Ranger.
Its cylindrical in style and matches the tube shape nicely, down the road I will pick up a good quality 45 degree one as well for daytime use, Dave.

#44 esldude

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Posted 27 January 2012 - 08:43 AM

Yes, I am using an old Orion diagonal. It definitely is a clear improvement over the prism. I save the prism for terrestrial daytime use.

#45 jrbarnett

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Posted 27 January 2012 - 12:59 PM

Any standard 1.25" star diagonal will work with the scope. I use a prism diagonal in mine (a Vixen). Many Celestron SCTs ship with 1.25" prism diagonals that buyers promptly replace. You should be able to pick one of those up used really, really cheaply.

Regards,

Jim

#46 jrbarnett

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Posted 27 January 2012 - 01:06 PM

That is nifty. Typically I don't like tabletop mounts, but that one (surveillance mode) sounds fun. Also, at $179 I would buy the one you list over the Celestron bundle. The Celestron bundle is now $179 too (was just $159 previously). Since I wouldn't use the tripod in the Celestron bundle or mount in the Skywatcher bundle very much, but the Skywatcher mount offers some fun features that the Celestron photo tripod does not, I'd probably go for the Skywatcher version at this point.

I also like the Skywatcher OTA better. It has less extraneous metal on it, and comes with a star diagonal rather than a correct image diagonal. The only downside is that it has just a 2-year warranty whereas the C90 has a lifetime warranty.

I've never used warranty service on any scope I've ever owned. I have returned scopes to dealers during the first 30-days for refund or exchange though. Most issues are obvious on receipt of the scope. Defects in materials an workmanship cropping up after 2 years are rare; usually it's ordinary wear an tear that triggers late-in-life issues.

Regards,

Jim

#47 Starlon

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Posted 28 January 2012 - 12:17 AM

Just picked up this little gem: http://www.celestron...-telescope.html Fantastic.. :jump:

I still cannot believe it..! The deal - and, you'll have to read what this thing can do. I almost ordered another - they are discontinuing it. For $179 you get the whole package. Still can't believe it!! So cool & can do so much.

Yeah Tell me about it, pulled the trigger on the same package about a week back thanks all to Jim....but have to wait till march to put my eyes on it as it has to be hand carried to India from the States.
Rahul

My devious plan is to try and plug my Nexstar SLT controller into the mount and see if it'll go-to....muhhuahhahahahaha!


Oh hey, they have them in stock: http://www.acephotod...sp?id=964844490

I got mine through Amazon - for Ace. Anyone else..? Go to either place.. also I think 1 or 2 other places I found. Get a 'spare', lol. You probably can cash-in when they are ALL gone..! :o

#48 Starlon

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Posted 28 January 2012 - 12:31 AM

Actually, you can undo the table top base & set the multi-mount on a tripod. It uses a 3/8 bolt. Then you have a motorized alt/az on a regular tripod. It comes with 3 Plossl ep's. Not too shabby a deal. I ought'a get paid for hyping it.. :grin:

#49 Starlon

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Posted 28 January 2012 - 07:36 PM

To XyrcesFenol ..yes - definitely. I use this: http://www.astronomi...product_id/AT1D

#50 darth panda

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Posted 06 February 2012 - 05:10 PM

Do you need an LAR to use that diagonal with this scope?






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