CPC 9.25 or Edge 800 HD AVX Mount

[daveangie0110]

Hi All

I am torn between two upgrade options for the replacement of my Nexstar 6SE, the dilemma i have is that i do 95% of my viewing from my small light polluted garden and the other problem is that i have only got good views to the south and south west, and very very limited views to the north.

I do planetary imaging using my ZWO camera and DSLR, and i am slowly getting into imaging some deep space objects i know i am limited to about 25 / 30 secs exposures due to my mount.

I like the fact that the CPC has built in GPS and will be quicker to set up over the Edge, but where i have very limited views to the north will i still be able to Polar align the Edge.

So will very limited views of the sky would it be better to go for a CPC or the Edge HD.

Thanks

[brantuk]

If you plan to do more dso imaging I would opt for the Edge ota on the AVX mount - but you'd need to get the "matched" reducer - your existing one won't work. The downside of the CPC is that it has a long focal length and it tracks in alt/az (two planes) - I would pick a whole other scope with a faster f-ratio myself (eg refractor).

Equatorial tracking (single plane) is available within the CPC electronics/software, but you need an equatorial wedge to polar align it for dso's. So there's a bit more setting up to do. Otherwise it's fine for planetary imaging. Hth

[PeterCPC]

I moved away from the CPC to AVX to do DSO imaging - its better suited.

Peter

[daveangie0110]

Out of these two which one would be better.

ED80 on a HEQ5 pro mount

C11 on a AVX mount.

If I went for the C11 could I still use my focal reducer on the C11 and my C6 OTA on either mount.

[Chris]

Out of these two which one would be better.

ED80 on a HEQ5 pro mount

C11 on a AVX mount.

If I went for the C11 could I still use my focal reducer on the C11 and my C6 OTA on either mount.

The first option would be much better for DSO imaging, and the second option would be better for planetary imaging and visual. 

I do think the C11 would be under mounted on the AVX though, I wouldn't go above the C9.25 on the AVX for visual if it was me. 

[brantuk]

The ED80 would be no problem on either of the two mounts - even with imaging and guiding accessories added on. But I think you've just been looking at the prices of reducers for the Edge ota's lol. Not cheap at all!

I agree with Chris - the C11 is 27.5lbs putting it right on the limit for those two mounts (30lbs carrying capacity) - I wouldn't use anything less than an NEQ6 Pro mount for that ota - it's carrying capacity is 40lbs plus counterweights.

[ollypenrice]

From a DS imaging point of view; Scopes with long focal lengths are not suitable for cameras with very small pixels. (Eg SCTs and DSLRs...)You end up trying to resolve tiny details far below what the atmosphere and the tracking will be likely to allow. I'm not at home so I don't have my handy tool for working out arcsecs per pixel available. However, weight on the mount will only be a small part of the problem if you are trying to autoguide at some fraction of an arcsecond per pixel and trying to do that unguided would be a waste of time. We would use a long focal length to make a small target fill the frame and show more detail. But if you cannot catch that detail because you are not tracking accurately enough what is the point of using a long focal length in the first place? None that I can see. You don't get the long FL detail because it is blurred out by the tracking errors. You would be likely to get the same real resolution plus a wider field of view by choosing a more realistic focal length - a considerably shorter one. The fewer arcsecs per pixel the better your tracking has to be. By the time you are at or below 1 arcsec per pixel it has to be very, very good indeed.

Olly

[Chris]

As you don't have your handy tool Olly, I can say he would be well below 1"/pixel with his DLSR and C8 or C9.25. 

I was at .97"/pixel with the C8 reduced, plus the chunky old school pixels of the 8MP Canon 350D.

[daveangie0110]

So it's better to get something like a ED80 on a HEQ5 pro mount, and can I use my 6" OTA on the HEQ5 mount if so what sort of images would I expect to get.