IC434 - separating Alnitak

[MarkS]

found it, you have to be x1 scale.

Oh yes, I've hit that before - anything that involves selecting or adding points on image will only work at 1:1 scale.

[Ivor]

Starting to get the the stretching correct in Iris however saving it is presenting a problem, the save function in the file menu and button don't appear to save the visualised image?

Tutorial on the Iris don't mention anything so I must be missing obvious step?

Another hint please?

[MarkS]

If you save as a BMP then you get exactly as it appears on the screen.
If you save as a TIF then first set the threshold sliders to 0 and 32767 and then multiply image by a constant "mult n" and maybe add an offset "offset n" so it looks right on the screen before saving.

Mark

[Ivor]

After a number of emails with Mark (thanks again) and much plotting in Excel to work out how asinh works I got it straight in my head and I think I can do it correctly in FITS liberator now.

After various processing in PS this is the end result of

RGB 8 -  x 10mins Ha - 11 x 10mins

Stacked in AA5
FLT110 ST8300M

[MarkS]

That's looking really good Ivor.  The structure in the nebulosity behind the horsehead has come out really well.

I'm not too sure about the colour however - maybe it's a lack of blue - I'm not quite sure.

You have succeeded in getting Altinak under control.

Overall it's a very good result.  Well done

Mark