Galaxy imaging: Nexstar 8 SE OTA opinions

[Ishan Mair]

I have a HEQ5 Pro which I use with a Skywatcher 130PDS and Canon 1100D DSLR. My interest has always been in imaging the galaxies. I could get an used celestron Nexstar 8 SE OTA only. What do you experienced imagers say? Can HEQ5 handle that beast and its focal length?

[michael.h.f.wilkinson]

Not really, I would think. Imagers with a lot more experience than I have say an EQ6 is out of its comfort zone beyond 1000mm focal length. Even with focal reducer you are looking at some 1280mm focal length. This requires a very sturdy and accurate mount.

[ollypenrice]

While FL is a good shorthand for estimating the likelihood of success a detailed assessment needs to look at the pixel scale. Your sig camera with this scope and focal reducer would be imaging at about 1.6 arcseconds per pixel. Without reducer you'd be at about an arcsecond. I wouldn't describe it as out of the question assuming good guiding but nor would I call it a doddle and you do need the seeing as well as the guiding for it to be worthwhile. Lots of UK imagers say that 2"PP is a nice place to be and you'd be below that. This means, if they are right, that you'd get the same real resolution and a wider field from a shorter FL. DSLRs also thrive on fast F ratios because they are time limited by thermal noise. How dark is your sky?

Olly

[Ishan Mair]

Thanks guys.

I too doubt the capability of my HEQ5 after the last night. Its a lemon.  5 arc-sec jitters were common last night - Why? I'm clueless.

Olly, at home, sky is quite polluted. Can just see Pleiades with naked eye. But I have access to a friend's farm in the country. That's quite a good sky. MW shows some good dark lanes there. Also, it seems you calculated the image scale with 130PDS instead of C8 OTA. My calculations give me about 0.8"PP with reducer. I didn't try to check without reducer looking at this number. Its just not worth it with my not-so-great HEQ5 mount. 

So I guess I'd drop that idea for imaging because it needs bigger mount and ccd with large pixels.  Now I believe what I read yesterday: Lack of money is the root of all evil.