CPC vs HEQ5

[riklaunim]

I'm thinking about getting something bigger - 8" SCT (or maybe 9,25") and I don't know which setup to choose (planetary and DS imaging):

1. CPC 800 (alt/az)

2. SCT 8" on equatorial mount (like HEQ5)

CPC can also use a wedge. It has GoTo, autoguiding port, PEC, and other goodies. HEQ5 has autoguiding port, PEC, and can have GoTo from a laptop via EQDIR (Syntrek). CPC is more mobile, while HEQ5 is not so mobile.

[SteveL]

A CPC8 on a wedge is not more mobile than an EQ5.... trust me! A CPC9.25 would be even worse.

Also, unless you are going to spend really silly money on a wedge to stop the whole top heavy thing wobling around like crazy, the EQ5 will be the better platform for imaging.

ALso, you can put any OTA you want the EQ mounts, sell the OTA get another... with the CPC, what you have is what you get, and changing the OTA means changing the whole setup.

And yes, I did have a NS8GPS (CPC forerunner) on a Celestron wedge, and now have a EQ6... no contest, and wish I had made the move earlier.

[brianb]

I agree.

If you need a luggable / fast set up scope & are happy for it to be altaz the CPC scopes are fine. My CPC1100 is manageable. But the tube & mount assembly is only manageable because it plonks down onto a level top ... one man fixing the mount onto an already installed wedge doesn't bear thinking about, and having the wedge pre-attached to the mount is going to make it a brute to cart around.

If DSO imaging is a priority, a GEM is definitely the way to go. The HEQ5 would probably be OK with an 8" SCT OTA but I'd be much happier with an EQ6 or CGEM.

[brantuk]

The 800 is a beautiful bit of kit, superb optics, all singing all dancing etc, but I do struggle at my limits to get it on a wedge - and the wedge is crazy expensive for what it is (as stated above). So if you choose this (alt/az) one it gives lovely views, you just gotta be fit to manage it - don't know how the others cope with 925 and 1100's.

A half decent EQ mount is gonna be great for AP and you can put whatever OTA you choose on it - and upgrading OTA's is easier. You'll get more bang for the buck. Me - I'd have one of each if the pennies weren't pinching.

Cheers

[ollypenrice]

I too ditched the wedge and fork mount (on a Meade 10 inch SCT) and put the OTA on a GEM, an EQ6. I found the fork mount a great thing in alt az for visual but horrible on a wedge. The wedge was murder to polar align because altering one screw changed everything else as well and it took forever. It looks okay as a system until you try to use it!

Be aware that imaging at that kind of focal length on deep sky requires very good tracking indeed and is right at the limit of what's possible on cheaper mounts. For my money a Meade 127 or SW 120 refractor would beat an 8 inch SCT on deep sky and work sweetly on an EQ mount with its okay-but-not-premium tracking.

The whole imaging experience would, in my view, be nicer. What you lose on image scale you recoup on sharpness and contrast. However, the SCT will win on the planets etc.

As for PEC being a goodie, well yes for visual but few people use it when autoguiding.

Most (though not all) feel that one set of commands works best.

Remember to budget for a Crayford focuser if you do go SCT because trying to focus with a moving mirror is another screaming nightmare.

I am aware that not everyone will agree with the above but it is based on experience with Meade 10inch SCT, Meade 'superwedge' (Huh!) and Meade 127 triplet/HEQ6.

Olly

PS I have been told to step away from the coffee when I get going on imaging with an SCT! I think this is a remarkably calm post, positively Zen, is it not??

[brianb]

Be aware that imaging at that kind of focal length on deep sky requires very good tracking indeed and is right at the limit of what's possible on cheaper mounts. For my money a Meade 127 or SW 120 refractor would beat an 8 inch SCT on deep sky and work sweetly on an EQ mount with its okay-but-not-premium tracking.

The whole imaging experience would, in my view, be nicer. What you lose on image scale you recoup on sharpness and contrast. However, the SCT will win on the planets etc.

I agree ... in fact I think that, for DSO imaging, an even smaller scope would work better ... the 600mm f/7.5 ED80 is about the right size for an EQ6. IMO.

And yes, Olly, your post is remarkably calm ... you can have that breakfast coffee now

[BlueAstra]

I faced a similar choice when I wanted to upgrade from a starter scope. I loved the idea of a cpc, but was aware of the issues with imaging. After advice from here I went for an EQ6 and never regretted it. For an OTA I went for a C8 SCT, bought as an Nexstar 8se since it was the same price as the OTA alone (!?). This also gives me a grab and go option.

[Whippy]

I agree ... in fact I think that, for DSO imaging, an even smaller scope would work better ... the 600mm f/7.5 ED80 is about the right size for an EQ6. IMO.

I've been using my ED80 for imaging in conjunction with the ZS66 for guiding a lot recently and it's the easiest setup I've used so far. Windproof, easy to balance (only one counterweight too), no worries about flexture, just bolt it all together and go. The ED120 sits great on an EQ6 only when the wind isn't an issue.

Tony..