What order is your workflow in PP?

[swag72]

Correct me if I'm wrong, but I think that the following need to be applied during PP to process your image. I guess what I'm interested in is in what order do you do these? Is there a better way round to do the? ie levels before curves, saturation at the end?

Levels

Curves

Colour balance

Saturation

Sharpening

NR

If I've missed anything then please add it. As a total newb, I'm bound to have missed loads!! If you can say what order you process in, that would be really helpful.

[Photosbykev]

I would put noise reduction 1st so that you aren't processing the noise during the workflow.

After saturation I would save a newly named tiff with layers, this is then your master reference file.

Any sharpening should be done after resizing for whatever media you intend to display the image on i.e the web, paper etc.

[Psychobilly]

Its often an iterative process.. especially the levels and curves bit.. and to some extent saturation changes as well..

Billy...

[roundycat]

It is always an iterative process!

Levels, three iterations, sometimes four; depends on the exposure level.

Curves, Often at least three iterations; initially to neutralise colour balance/bias.

Dupe layer, Threshold, star layer. Use R channel in NB.

Dupe background, set to Overlay, apply High Pass - carefully.

Adjust HP layer and flatten.

Neat Image. Don't do it at the beginning as you cannot see the noise. The filter result needs very careful examination before you approve it.

Final colour tweaks in Curves?

Unsharp Mask sharpening - apply very carefully.

Send to the printer.

All this is after standard calibration, alignment and combination in Maxim. Combination usually using Median or SD Mask output which will get rid of a lot of the noise.

Dennis

[swag72]

Excellent, thanks for those pointers.

[ollypenrice]

Very interesting to get this insight in the flow of others. I am with Dennis though there are a couple of new ones in there for me. I have never used High Pass, for instance.

I would stress doing colour balance as a part of levels and curves after the first two or three stretches and cutbacks. I try to ensure that the top left of the histogram of each colour ligns up, which means not cutting back the black point too aggressively. Remember that this cutting back is a noise reduction technique.

Olly

[roundycat]

just a rider to Olly's comments. Setting colour balance/bias is clearly very important but I do it by measuring the colour using the cursor and Info Palette or colour samplers and the Info Palette automatic extension.

Watching the histogram by definition ignores the actual picture that you are fine tuning, that's what you should be watching! Also if you try to adjust colour too early you may find you have adjusted it to completely the wrong colour because you could not see it properly.

There is a fine line to be drawn between watching the colour in the picture as it 'develops' and measuring the colour. Your eyes can be very deceiving.

Dennis

[dlp]

I've found High Pass quite useful, usually with a big gaussian blur (40px on a 1600px wide image), and I use soft light as the blending method, adjusting transparency as necessary.

Incidentally, I learned when doing PS for press to always do sharpening before levels as you might blow out the highlights with the sharpening.

David

[SteveP]

Swag

This is my process for 'vanilla' RGB. It's very much in line with others

'Pre-processing'

Calibration

Align

Stack

Remove hot pixels

Processing combined images

Remove colour bias (using levels & curves)

Remove Gradients

Levels & curves iterations (several!) - enhance dim and mid tones especially

Smooth dim regions

Sharpen bright regions

Apply Hue & Saturation (only if needed)

Final minor adjustmentss in Levels & Curves

Flatten

Save!!

HTH

Steve

[Psychobilly]

I would "save as" quite often and especially if you have reached a point where you might want to try different approaches to the processing.. I never trust the undo's...

[ollypenrice]

just a rider to Olly's comments. Setting colour balance/bias is clearly very important but I do it by measuring the colour using the cursor and Info Palette or colour samplers and the Info Palette automatic extension.

Watching the histogram by definition ignores the actual picture that you are fine tuning, that's what you should be watching! Also if you try to adjust colour too early you may find you have adjusted it to completely the wrong colour because you could not see it properly.

There is a fine line to be drawn between watching the colour in the picture as it 'develops' and measuring the colour. Your eyes can be very deceiving.

Dennis

Very fair point, Dennis, but what are you looking for in your measurement of samples? Is it the background sky value you are looking at? Equal RGB distribution?

I ditto Peter on lots of Save As. I just add suffixes P (for processed) 1, 2 etc.

Olly

[dlp]

My 'Save As' = take snapshot in history pane, and just press Ctrl-s now and then! That also has the benefit of being easily able to clone something back in using the history brush.

David

[roundycat]

Olly, the whole business of measuring colour on something where you don't know the colour is a bit hit and miss, that goes without saying. The thing is most galaxies have a neutral background, if you can call a deep blue neutral! If the flats work you can usually set somewhere near the proper colour by measurement. What you (I!) can't do is to reliably set the colour by eye when the overall brightness/colour of the pictures vary and when you go from processing in daylight or at dusk to full blooded nighttime when the room lighting plays a big part. The Info Palette helps to overcome all these variables.

Overall I tend to try and make my current picture look a bit like the best I have ever done.

Dennis

[Digz]

I would "save as" quite often and especially if you have reached a point where you might want to try different approaches to the processing.. I never trust the undo's...

Another alternative if using Photoshop is to make sure each curve / levels iteration is on its own adjustment layer (each one can be labelled to clearly define what it is) that way they can be switched on and off and if over done they are easily editable.

Also, when duplicating layers to run, say, a high pass sharpening routine you can turn this new layer into a smart object which means when the high pass filter has been applied you can actually go back and edit the amount etc.

HTH.

[msinclairinork]

Sorry to butt in...

I don't use levels, just curves(so far) because I was under the impression not to use levels if there is a thin line across the bottom..which 99.99999% of the time (for me) there is. Also I find them to be to harsh?

I like just doing little iterations in curves. It for me, gives me more control over the hole image ie high-lights/mid tone's etc

Is this good/bad?

Thanks,

Michael

[ollypenrice]

Bad, I think!

If you do an aggressive first couple of curves you lift the bottom (dark) part very steeply and then, near the top, bend it over hard and let the line stay straight as it heads for the top right hand corner. (I am assuming the bottom left is the dark part but Ps can reverse that as some prefer.)

After each of these initial aggressive curves go into Levels. Now you will see the foot of the peak has widened (good, this is the opening up of the data that you want in an astro image). And it has also moved to the right. Much of the thin line to the left of the foot of the peak is noise and can be cut back, but not too much because some of it is still data.

Olly

[roundycat]

On the other hand...

If you move the top right of the curve to the left or the bottom left of the curve to the right you are using the same basic algorithm as for shifting the black or white points in Levels.

I always have a quick look at the histogram in Levels before I do, usually, two or three Gamma only stretches using Levels. Once the data is being drawn out (look at the picture now!), then I switch to Curves for the finer control.

If you make a simple gamma shift using Curves (move the centre to the left) you can get a very similar result to that obtainable from Levels (move the gamma slider to the left to a value of 2). It is only similar, not the same. These subtle nuances are what you need to get a grip on with both these tools.

Dennis

[dlp]

I think as long as you keep your eye on the histogram for clipping (and for both tools you can turn on visualisation of that) and combing, I don't think it matters which you use.

Perceived wisdom in doing photos for print was that levels was the sledgehammer and curves the scalpel.

David

[themos]

If you're hardcore like me (yeah. right) you find a G6 star in the image and then white balance on that.

[msinclairinork]

cheers for the reply guys.

Michael