136 replies to this topic

[mayhem13]

I hear lots of great things about the optics on these little SCTs. What is the reason for their sharpness? Are they really exceptionally sharp or is it just that people don't expect sharp images from such small scopes?

 

Maybe the smaller mirror and corrector lens are easier to get a smoother figure.  
 

Bill

I would imagine this has something to do with it. 

 

And here's a tip......flock the inside of the baffle tube.....the black plastic stock is shiny.....once flocked, the contrast increases considerably. It's not hard to do, just cut a piece to length the same as the inside circumference and roll it up.....place it in the tube and let the roll expand and done

[Echolight]

If you are not familiar with Ed Ting, he provides excellent reviews of equipment.

 

Here is his C5 review, he discusses reasonable mounts and the features of the C5

 

https://youtu.be/Iza...?feature=shared

 

The C5 is the classic travel scope....they even had one in space, as you can see in the review by Ed!

 

Since 'size' of an SCT OTA goes like the aperture cubed, c5 is considerably smaller than the c6, it might even be the sweet spot in small scopes.

 

Bob

Can't believe Ed indiscriminately said not to use a photo tripod and then immediately suggests a Porta II that puts the focuser on top and the finder on the bottom!

 

Here's a sturdily mounted one hand out the door on the mount grab and go that throws up a perfect star test, does 275x on the Moon, aaaannnnd gets around 2.3 degrees true field of view at 44x with a 20 Hyperwide. 

(It's got the secret sauce) 

 

Really hard to beat for a little scope that hits like a hammer and is really never too much trouble to take out.

Little 60-80mm apo refractors can't touch this for a bright high power image. 

https://youtu.be/otC...Ml5VuvJWKhNv8ZN

 

Should easily outdo a 90mm f10 achromat at high power. And be way smaller. Easier to look through.

 

My 130 f5 parabolic newt is it's optical equal. Maybe a skosh brighter, and a little wider. But taking it out is a clumsy two hand affair.

Edited by Echolight, 06 October 2023 - 07:22 PM.

[Bob Campbell]

Can't believe Ed indiscriminately said not to use a photo tripod and then immediately suggests a Porta II that puts the focuser on top and the finder on the bottom!

 

Ed is a contortionist in his spare time Looks like you have a cool setup. 

 

Bob

[RichA]

The C5 is a reflector so should not have any chromatic aberration with the exception of any that is possibly introduced from the corrector plate.  In my C5, I've never seen a hint of CA.

 

-Dan

No, most SCTs and Maks show little if any.  Back to the other point, the C5 has only one issue, it gets back-heavy fast if you put 2" gear on it. 

[Echolight]

Ed is a contortionist in his spare time Looks like you have a cool setup. 

 

Bob

Thanks! Yeah, it's fun. 

Lately, since the weather has been most ideal, and the mosquitos disappeared, I've been taking out fast larger aperture scopes for richfield in Cygnus.

But the little C5 never gets shelved. It's always at the ready. Love it for some quick weeknight high mag lunar views.

[Echolight]

For travel purposes it would definitely be a manual mount. If I want to do any AP with it it'll be from home and I'll put it on my usual go-to mount that I use with the newt. Thanks for the suggestion of mounts though I'll take a look at that AZ5

Most C5's are left hand mount.  In order to keep the focuser on the bottom and the finder on top.

 

The only currently available left side one arm alt/az manual mount that I know of is the ES Twilight I.

Although there are several other small alt/az heads that allow mounting on either side.

Edited by Echolight, 06 October 2023 - 07:38 PM.

[Echolight]

That's pretty high praise for the C6. I have looked at that one before as well, though I hadn't really considered it for grab n go purposes for some reason. I'm not buying right now, but I think you might have a point. Unless I see a C5 for really cheap when I'm actually in the market to buy, I'll probably get a C6 since I had also thought of getting the hyperstar attachment for it and using it at f/2 for wide field imaging. The potential with the C6 to have 3 or 4 different ways to use it is quite attractive. Thanks for the mount suggestions as well!

The C5 is like carrying a football. A C6 like a watermelon.

Right after I got my C5, I was intending to sell my C6. But in my excitement over the C5, I fumbled the giant C6  ....and now I don't think it would bring a fair return.

 

Even know it has a single crack, I might still try it with a Hyperstar some day. 

I've always thought if I was going to get into AP it would be with a C6 and a Hyperstar. I mean a Hyperstar for a C8 costs twice as much! And the C6 is like a rock on an AVX.

Edited by Echolight, 06 October 2023 - 07:48 PM.

[Bob Campbell]

I've always thought if I was going to get into AP it would be with a C6 and a Hyperstar. I mean a Hyperstar for a C8 costs twice as much! And the C6 is like a rock on an AVX.

That is the plan (EAA not AP) for my c6 down the road when I find an extra $500 under the couch cushions. For now I run it at f10 f6.3 f20. Pretty versatile.

 

Bob

[Echolight]

That is the plan (EAA not AP) for my c6 down the road when I find an extra $500 under the couch cushions. For now I run it at f10 f6.3 f20. Pretty versatile.

 

Bob

I would probably do EAA also. AP sounds like a full time job.

[Anony]

 

 

Should easily outdo a 90mm f10 achromat at high power. And be way smaller. Easier to look through.

 

Yep, C5 does out do it at high power... especially for CA prone targets (planets/lunar). I own both -- only reason I ever take the 90mm out is if I want to test something, or as a change of pace... or during winter when I don't want to wait for cool down.

 

And even then, as I bash through the doorways with my 90mm, I second-guess myself and wonder if it's worth the hassle... especially when I realize the best targets are near zenith. It's not exactly the most ergonomic scope.

 

C5 on the other hand is a cute little fat scope, and can handle most viewing positions well. I probably should get it a coat and wouldn't have to worry about cooldown so much.

[tdavis4785]

I use my C5 on an AZ-GTi. The point and track feature makes it quick and easy to use.

[Bob Campbell]

I would probably do EAA also. AP sounds like a full time job.

Exactly why I don't do AP

 

Bob

[Echolight]

Yep, C5 does out do it at high power... especially for CA prone targets (planets/lunar). I own both -- only reason I ever take the 90mm out is if I want to test something, or as a change of pace... or during winter when I don't want to wait for cool down.

 

And even then, as I bash through the doorways with my 90mm, I second-guess myself and wonder if it's worth the hassle... especially when I realize the best targets are near zenith. It's not exactly the most ergonomic scope.

 

C5 on the other hand is a cute little fat scope, and can handle most viewing positions well. I probably should get it a coat and wouldn't have to worry about cooldown so much.

Yep. The C5 is like having a telescope without having a telescope.

 

I don't think it takes much to acclimate. I've never noticed it being affected yet.

[RichA]

The C5 is like carrying a football. A C6 like a watermelon.

Right after I got my C5, I was intending to sell my C6. But in my excitement over the C5, I fumbled the giant C6  ....and now I don't think it would bring a fair return.

 

Even know it has a single crack, I might still try it with a Hyperstar some day. 

I've always thought if I was going to get into AP it would be with a C6 and a Hyperstar. I mean a Hyperstar for a C8 costs twice as much! And the C6 is like a rock on an AVX.

Make sure the screws holding the corrector aren't very tight so they don't flex  the glass, it should work fine.

[mclewis1]

...  Back to the other point, the C5 has only one issue, it gets back-heavy fast if you put 2" gear on it. 

There is one other area to consider if you go with 2" gear. Notice the focuser knob in Echolight's great pics ... you may have to watch for interference with your 2" gear, particularly if you mount it close to the rear cell surface on smaller scopes. 

 

On my C6 there was a problem with a WO SCT threaded diagonal in some orientations with the stock rubber covered knob (pulling the rubber knob off fixed that). I also have a short 2" visual back that pushes a barrel diagonal far enough back ... but I then have to remove the big threaded set screws when installing it ... I can't win  .

[Doug Culbertson]

Yep. The C5 is like having a telescope without having a telescope.

 

I don't think it takes much to acclimate. I've never noticed it being affected yet.

Well, I now have a C5 on the way. Since I didn’t want the StarSense stuff that comes with the Popular Science model, didn’t want the hassle of selling what I didn’t want, I bought the spotting model that comes with the nice little case. I will be using it on a 54mm ball camera mount on my Innorel RT80c tripod. Stick a zoom eyepiece on it and it’s one hand out the door. 
 

Any suggestions for a dew shield? 

[Bill Barlow]

AstroZap sells one for the C5 with a precut notch for the mounting rail.  That’s what I use with mine.  Several vendors carry them including AstroZap.  

 

Bill

[Echolight]

There is one other area to consider if you go with 2" gear. Notice the focuser knob in Echolight's great pics ... you may have to watch for interference with your 2" gear, particularly if you mount it close to the rear cell surface on smaller scopes. 

 

On my C6 there was a problem with a WO SCT threaded diagonal in some orientations with the stock rubber covered knob (pulling the rubber knob off fixed that). I also have a short 2" visual back that pushes a barrel diagonal far enough back ... but I then have to remove the big threaded set screws when installing it ... I can't win  .

I could trim the top off of the rubber knob and fit it on there.

Or fashion a small knurled edge wheel. 

 

But focusing hasn't been an issue.

The little C5 is shimmy free on the 26 pound capacity tripod (conservative by photo industry standards), and 90 pound capacity ball head.

 

---------------

 

As far as being back heavy as mentioned in another post.....

 

For starters, the rear cell that surrounds the primary mirror seems to be where most of the weight of the C5 is. 

Unlike other telescopes, the weight of the very compact C5 is very centrally located. So the combination of short length and centrally located mass, leads to a minimal moment arm.

 

And my Arca Swiss rail extends a bit past the Vixen dovetail that it is bolted to. Back to right about even with the back of the cell. So the back of my Arca-Swiss clamp is a bit behind the back of the Vixen dovetail.

 

Once balanced, the C5 is the only telescope I have that is never affected when changing out 25 ounce eyepieces. The altitude never needs be tightened... Although the ball on my ball head is aspheric, and does provide a slight amount of resistance even when the tensioner is fully loose.

[Echolight]

Well, I now have a C5 on the way. Since I didn’t want the StarSense stuff that comes with the Popular Science model, didn’t want the hassle of selling what I didn’t want, I bought the spotting model that comes with the nice little case. I will be using it on a 54mm ball camera mount on my Innorel RT80c tripod. Stick a zoom eyepiece on it and it’s one hand out the door. 
 

Any suggestions for a dew shield? 

You'll probably need an elevating center column for clearance if side mounted, using the ball head in portrait mode as an alt/az.

 

I'm using a 140mm Arca-Swiss plate with about a 2 inch long slot on each end bolted to the two holes on the back half of the Vixen dovetail.

I believe it is this one that comes with two 1/4-20 screws.

https://www.amazon.c...0/dp/B0087G0NYM

[Doug Culbertson]

You'll probably need an elevating center column for clearance if side mounted, using the ball head in portrait mode as an alt/az.

 

I'm using a 140mm Arca-Swiss plate with about a 2 inch long slot on each end bolted to the two holes on the back half of the Vixen dovetail.

I believe it is this one that comes with two 1/4-20 screws.

https://www.amazon.c...0/dp/B0087G0NYM

Thanks. I do have a SkyWatcher column for their AZ GTi and other mounts. I also have a 100mm Arca-Swiss plate bolted to the bottom of the 6" dovetail on myAT60ED shown below, but I like the look of that 140mm. Wiat I am considering trying is to attach this saddle to an Arca-Swiss plate and just use the Vixen dovetails on both the C5 and the AT60ED. https://www.amazon.c...1?ie=UTF8&psc=1

 

FWIW, I returned the Artcise ball head in the photo below and bought a 54mm Neewer ball because the panoramic scale on the Artcise didn't make sense. 

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[Echolight]

Thanks. I do have a SkyWatcher column for their AZ GTi and other mounts. I also have a 100mm Arca-Swiss plate bolted to the bottom of the 6" dovetail on myAT60ED shown below, but I like the look of that 140mm. Wiat I am considering trying is to attach this saddle to an Arca-Swiss plate and just use the Vixen dovetails on both the C5 and the AT60ED. https://www.amazon.c...1?ie=UTF8&psc=1

 

FWIW, I returned the Artcise ball head in the photo below and bought a 54mm Neewer ball because the panoramic scale on the Artcise didn't make sense. 

That will give plenty of clearance!

And is probably more stable than an elevating column.

Since it is back heavy. And usually mounted a bit forward. The C5 needs very little adjustment when viewing at different elevations.

 

I've seen others on here attach a clamp like that to a ball head. So certainly it should be doable.

[Bob Campbell]

Thanks. I do have a SkyWatcher column for their AZ GTi and other mounts. I also have a 100mm Arca-Swiss plate bolted to the bottom of the 6" dovetail on myAT60ED shown below, but I like the look of that 140mm. Wiat I am considering trying is to attach this saddle to an Arca-Swiss plate and just use the Vixen dovetails on both the C5 and the AT60ED. https://www.amazon.c...1?ie=UTF8&psc=1

 

FWIW, I returned the Artcise ball head in the photo below and bought a 54mm Neewer ball because the panoramic scale on the Artcise didn't make sense. 

Pretty, functional, and economical. Couldn't be better!

 

Bob

[CHASLX200]

No, most SCTs and Maks show little if any.  Back to the other point, the C5 has only one issue, it gets back-heavy fast if you put 2" gear on it. 

What good does 2" stuff do on a C5?  Seems you can't get the whole FOV of 2" stuff.  Just makes the OTA flop down.

[CHASLX200]

C5 works fine on my GP mount.

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[CHASLX200]

I'm not sure if it's basically the same optics - but I just picked up a used Celestron 5se on Friday (for $500, FB Marketplace). Same focal length, Starbright coatings, etc, but Celestron lists its diameter at 125mm (instead of 127mm like the C5).

Only used it on Jupiter, Saturn, and the Moon so far... but I gotta say, I was pretty blown away by its sharpness at higher powers. I pushed it a bit beyond its theoretical limit (250x) to 266x, and still had really nice, sharp views of J & S. I'm thrilled with the purchase so far!

If you luck into a freaky sharp C5 then 350x is easy on some objects.