Processing problems

[malc-c]

For those who have not been following my issue setting my mount up for use with EQMOD, I've been having alignment and tracking problems when using EQMOD, but as last night was such an opportunity to do some imaging into the small hours and not have to worry about work the following morning I thought I would have a go at M31.

Cutting a long story short using APT I managed to take around a dozen images at 800ISO with an 80 second exposure, and 5 darks before the battery discharged. This was also the 1st time I had attached the light pollution clip filter in the Canon 400D, and the results on the screen looked good.

However when I came to process them in DSS the resulting image comes out with a pink - red background, and any attempt to adjust this using the sliders makes the final image worse than a single 5min exposure (although there is more trailing in the 5min exposure).

If I can sort out a place to upload the images (65mb rar file containg jpg images) would some of you processing gurus take a look and see what you can do ?

[Shibby]

The pink/red is likely down to camera noise and remaining LP. It probably only looks "worse" because you'll be stretching the levels in the image.

After stacking the image, you can fix the colour balance in post-processing (no need to use DSS sliders). Alternatively, try using RGB background calibration when stacking.

[malc-c]

I've uploaded the jpgs (raws are too large). Would love to see if something constructive could be done with them

http://micro-heli.co.uk/M31jpg.rar

[Black Knight]

Had a go at stacking your jpgs. Didn't get a pinky-red background, although there is a bit if a reddish gradient. There is a fair bit of noise, but this is probably just from the jpgs themselves. I'm not a processing guru so I didn't try any post-processing in Photoshop.

Have you tried AndyUK's DSS settings? They might help you out a bit - they have done for me . They are in this thread, towards the end of the first page:

http://stargazerslounge.com/imaging-image-processing-help-techniques/150121-dss-problem-ngc7000.html

Try re-registering and re-stacking with these settings and see if it makes a difference.

[malc-c]

Thanks,

Followed those settings and yes I can now get a darker background, but the images looks so false.

Is there any way to stack the individual images in PS or something that doesn't do all that artifact processing ?

[PhoenixRising]

You really need to be shooting in RAW+JPEG. Then stacking the raws into DSS and processing the resulting tiff from there. Jpegs just lose too much information.

[malc-c]

Thanks for the tip. I'll try this with the raw images tomorrow after work. In the meantime I've just done this by stacking layers in PS and then tweaking with the curves. Came out blue when uploaded, but I guess that's just playing with the RGB levels