Stephan's Quintet, size matters!

[DaveS]

A couple of images of Stephan's Quintet with telescopes of very different sizes and budgets.

Firstly 12 hours LRGB (6 hours Lum, 2 hours each RGB) with my ODK 12, 0.3M f/6.8 at a nominal 0.46"/px from my back garden on the Dorset coast.

 

Secondly, 6 minutes RGB with the Liverpool Telescope, 2.0M f/10 at a plate scale of 0.30"/px from a mountain on La Palma.

*sigh*

[Nik271]

The Liverpool wins but not by as much as the 7 fold difference in aperture suggest. It shows that the limiting factor is mostly the atmospheric seeing. The image scale being similar the Liverpool is expected to be about  50 times faster which is compensated by the 6hrs/6mins ratio of integration times. So my take on this is that the seeing in LaPalma is much better than in the UK. Had you taken your scope to LaPalma probably the images would be much closer. Astrobiscuit tried exactly this some time ago and discovered his  8 inch reflector is not big enough, but something a bit larger will be very competitive.

[vlaiv]

Very nice example that shows how F/10 - or "slower" telescope can be much faster than F/6.8 - or "faster" one.

Btw, resolution aside, I think that as far as "depth" goes - images are comparable. Same objects can be identified in both images to the roughly the same SNR.

[rl]

Personally I think that's quite a good advert for the ODK...