Average, Median, Sigma Clip or other?

Michael,

Absolutely no problem with asking! I use AIP4Win V2 .... although I do not use Maxim for reduction, I am almost certain it does have a sigma-sum combine option.

Cheers Anthony.
Do you usually use AIP4WIN for most of you processing or is it just used to combine the images before working on the resultant image in Photoshop?

FWIW, what I'm doing at the moment is combining the images in Maxim, applying DDP without sharpening in Maxim and then working on the resultant image in Photoshop.

Regards,

Cheers Anthony.
Do you usually use AIP4WIN for most of you processing or is it just used to combine the images before working on the resultant image in Photoshop?

Hi Michael,

The reduction involving darks, flats and flat-darks is accomplished using CCDSoft and the wonderful interface they have where one can specify complete folders to be reduced (it is very quick and easy).

I will then go into AIP4Win and oversample my images to 200% of the original size for registration and stacking with a correction for atmosheric extinction. I will then proceed with deconvolution of my luminance layer. Finally I will pursue DDP and followed by a min-max operation for pixels with negative ADU's or ADU's above 65,535. All of this leads to my master Lum, master Red, master Green and master Blue files.

Now is time for Photoshop where I will load the four master files using FITS Liberator as an intermediary to convert my 32-bit FITS files into PS files. The real processing begins within PS and involves background normalization, levels, curves etc etc etc.

Interesting thread and a topic I have thought about a lot. In the end I dump them all out and see which one does the biz. 9/10 I find an average combine works best. Thanks Anthony for the detailed info which I too found very useful.

FWIW heres my processing steps for a lum image (generally)

Images Plus, dark, flat and bias calibrate each image. With average combine for the calibration frames.
Translation and rotation (and scale if required, rarely)
Combine

DDP
Star size reduction
Levels and curves.
Perhaps a bit of adaptive contrast
Deconvolution (usually Lucy-Richardson)

Then to PS

Some minor adjustments. Clone out the odd bad pixel that escapes the darks. Obviously do the LRGB stuff if applicable. Output.

The to Neat Image Pro

Back to PS. Resize a copy and output as JPG (High) for web.

Obviously it can vary from image to image but most of the time it works out like that.

Images Plus, dark, flat and bias calibrate each image. With average combine for the calibration frames.

Dave - I know flats aren't 'subtracted - I think they are divided. Anthony will know...

Then again, perhaps Images Plus knows exactly what to do with them...

Thanks for sharing the flow though.

Cheers
Dave

Dave - I know flats aren't 'subtracted - I think they are divided. Anthony will know...

I don't think I said they were subtracted? Flats are divided. Anyway IP worries about all that. All you need do is point it at the darks flats and bias frames and it worries about the rest.