rough settings please ed80 and d750 and whirlpool galaxy

[iwols]

hi all after a poor night last night with my c8 reverted back to ed80 and a d750 camera,going to concentrate on one object instead of  flipping around and m51(whirlpool)looks obtainable ,just wondered if anyone could give me some rough camera settings just to get me going again,using heq5 and stellarium thanks(in need of insperation) thanks guys  with an option of adding a 2.25 barlow

[MattJenko]

Just using the D750 at native focal length gives you 2"/pixel, which should be good, although you will need to crop, as the galaxy will appear very small and I imagine the edges of a full frame camera are going to suffer in an ED80 anyway. The barlow will spread the galaxy over more pixels (increase resolution) at the cost of increasing your imaging time to get the same level of brightness/image as the non-barlowed version.

Wouldn't some of the Cygnus nebula regions be a more fitting target for a full frame camera and a 600mm focal length 80mm refractor - assuming no reducer - although you will benefit from a flattener of some description?

[Marky1973]

Hi Iwols

My last effort with the Whirpool is detailed here:

https://markwalkerscreenwriting.wordpress.com/2016/04/05/m51-the-whirpool-galaxy-take-2/

I don't have a nikon, but this was 3 hours worth of 8 minute subs, plus the usual calibration frames (cropped). There may be more data in there for processing, but I am still working on that - but you do need a lot of data, and probably a lot more subs if you are not guiding and are limited in terms of sub length. This was with the ED80 and 0.85 reducer. ISO800 with CLS CCD Clip Filter.

I wold set up, figure out what the longest sub you can manage is and then take as many of them as you can! Nice clear night here (so far) so might have a go myself!