M31 Headache

[Pluto]

Hi all After waiting months to get my gear sorted i managed to take 5x500sec subs of M31.I know the galaxy isn't

in the center but i was happy that i got something on the screen.The only problem Ive got is stacking them and processing the images,i spent 7 hours yesterday without any luck.i know I'm not going to be genius at it in a day but some sort of reward would have been nice instead of a headache.Can someone have ago at these pictures to see if they are any good,and post them back so at least Ive got an idea what they should look like,so then i can attempt to have ago to get the same sort of results. the pictures are on UK Astronomers site under plpluto.

please remember this was my first attempt. THANKS

[SteveL]

downloading them now, will have a play later today and post the results

[Ant]

I can download tonight and have a play.

Ant

[Grant]

Heres a quick link to the files: http://ukastronomers.com/plPluto/action/files/show/6/pagenum/1/commentpage/1

Just downloading now...

[SteveL]

You picked a hell of a first object to image and process

I think your focus is just a touch out in the centre (ignore the outer area, the WO66 tends to do that to objects without the field flattener). Also ignore the odd dark patch just below left of M31, thats me being a bit over zealous with the gradient removal. By the way, you have some great star colours in this image.

[steppenwolf]

I too had a look at this image and confirm the focus is a little soft. Unfortunately, my RGB conversion came out very blue, probably as I am calibrated for my SXVF CCD which has different offsets etc. I dropped one frame as it was way out of line with the others but it was clear that there was some nice data there within the other images.

For your first shot you've done well as this is not a trivial object to image as there is a difficult balance to be found between capturing the dust lanes without burning out the core! Focus is always problematical but well worth taking the time on - my best advice here is to set the focus on a bright star before slewing to the 'main event' as this will ensure that the focus is pretty much spot on.

Keep 'em coming, you have made a good start.

[Pluto]

Thanks All for your help and advice,time to get the laptop out and reproduce what SteveL has managed. hopefully in this life time

Just a couple of questions

When you take the pictures in maxim dl do you convert them to colour before you stack them in deepskystacker

or can you do that in photoshop or deepskystacker.

SteveL is it worth getting that William Optics 0.8x Reducer / Flattener for the APO66 as well as the CLS filter for the QHY8

Thanks again

[steppenwolf]

Always convert to RGB before you stack otherwise you will destroy the Bayer Matrix encoding.

As you have MaximDL, why don't you stack the images in Maxim? - it has a very powerful stacking tool. Maxim simply calls this 'combine' and you will find the feature under the 'Process' tab.

[SteveL]

DeepSkyStacker has a debayer option for the QHY8 (its under the RAW/FITS DDP Settings), so no need to debayer them before feeding them into DSS, it will be done before stacking for you. I find that my images tend to be a bit low in the blue channel, and so use red balance 1/blue balance 1.5 in the FITS options in DSS, and that evens stuff up a bit.

WO field flattener (the Mk II version, specially for the WO66)... for larger format CCDs, its an essential addition. I get flat field right out to the edge of FOV on my WO66 + FF + QHY8.

CLS filter - depends on your local light pollution. Your images didnt show too much (or any!) light pollution, so buying a CLS may be over kill.

Where you autoguiding when you took these images?

[Pluto]

Yes i was autoguiding with the qhy5 with my Celestron C6 at f10. I was using maxim dl software to guide.

I was trying to get 12x300 sec subs but half way through pic 5 i lost the guiding due to clouds.