Iris Nebula - Reprocessed

[Gina]

Had a go at reprocessing my Iris Nebula data. ISO1600, 60s, 12C (no cooling) with 51 lights, 15 darks, 151 flats. DSS chose 40 out of the 51 lights. Saved without adjustment as 16 bit TIFF and then processed in PS with numerous goes with curves and levels, noise reduction, colour balance and contrast etc. Severely cropped as the image was right near the bottom of the frame. Saved as PNG. Had to really struggle to get anything out of this - it needs another go with more and longer subs with cooling to bring out any serious data from this dim object.

[squeaky]

That looks like a really tough target.

Question: Do you crop first, or last?

[Gina]

That looks like a really tough target.

Question: Do you crop first, or last?

I usually crop first so that I can see what I'm doing better - slightly faster processing too. I crop then Fit on Screen from the View menu. But this time I used curves a few times to make the image appear first. You're right - this target is far from easy.

[squeaky]

Yeah, I crop first too, again because it can help speed processing.

I've found that in some cases, while fit to screen size can be useful... so can going to 400% to get a really good feel for noise and for sharpness. Some of the processes might, for example, stretch the histogram but may also add noise. Looking in "tight" can give you the means to trial stretching a bit less, or a bit more to get "some" improvement without adding so much noise - OR losing too much detail.

If I actually knew what the heck I was doing I wouldn't need to do so much "By God and by guess" processing

[Gina]

Yeah, I crop first too, again because it can help speed processing.

I've found that in some cases, while fit to screen size can be useful... so can going to 400% to get a really good feel for noise and for sharpness. Some of the processes might, for example, stretch the histogram but may also add noise. Looking in "tight" can give you the means to trial stretching a bit less, or a bit more to get "some" improvement without adding so much noise - OR losing too much detail.

Yes, I do that sometimes too

If I actually knew what the heck I was doing I wouldn't need to do so much "By God and by guess" processing

He he.. Yes, I've been like that at times But it can be good - you learn by trying things - see what works

[urho1952]

I support like

[Quatermass]

This was quite tricky needed a really good dark night to get more detail lifted out. I found with this and several other nebula that using a luminance layer when I was done really help bringing things out a bit more here is the tutorial for the method.

http://youtu.be/qYd7loeEXnA

[Gina]

I've play that video later Mark - thank you

I think the Iris Nebula wants a lot more and longer subs. The data I have is very faint and I had to work hard to tease anything out. In turn of course we want some clear skies!

[Quatermass]

Yes clear skies would be very nice please in fact a summer of some kind would be nice as well

[Gina]

It would indeed! Glug, glug, up periscope