Stacking - workflow

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ChrisR
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Stacking - workflow

Post by ChrisR »

There's a detailed thread here http://photomacrography.net/forum/viewt ... 5735#35735
but I'm more than a little hazy about how to do things, and indeed what I'm looking at. That thread may also be a litttle dated now.

What I'm seeing is jpeg artifacts in the source images produced by my camera (D700, 12 bit lossless compressed, best Q jpeg, no sharpening ).
These 3 crops show part of what's just a red whisker.
Image
Left is one Raw frame from the stack
Center/right is from ZereneStacker, center is the same frame, Jpeg, and right is the output Pmap file.

The focus steps in the stack are close enough,, the adjacent frames don't look much different.
I think I may be losing something, though perhaps I'm just reaching the end of the kit's, and my, capabilities. Rigidness, exposure and lighting could be bettter.

I could produce Tiff files in the camera, (slow slow, I expect, and does anyone do that?)
or probably batch convert from Raw to Tiff in Photoshop CS4 ( :? never tried that),
or probably in Nikon Capture NX2, ( :? which I haven't used much at all.)

Someone will have been round these loops, I'm sure.
I would be grateful for any guidance.

rjlittlefield
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Post by rjlittlefield »

Chris, I suspect you're being misled by a peculiarity of Zerene Stacker's user interface.

The peculiarity is that most of the time, the source image window is not showing a "pure" form of the input, but rather it is showing a low-quality JPEG that has been produced internally to allow fast navigation between frames. If you look inside a project folder at the "previewimages" folder, those low-quality JPEGs are what you'll be seeing.

The only reliable way to see "pure" input using ZS is to fire up the retouching tool. When retouching, the source window shows low quality compressed preview images while you're navigating, then updates to show pure input when you release the mouse button and/or shift key. Of course the stacking process always uses the "pure" input internally, not the low-quality preview versions.

Images in the ZS output window are not compressed, by the way. That's why they take a lot longer to navigate between, and also why this one looks so much better than the "corresponding" input.

I'll bet that if you look at the camera's JPEGs using Photoshop, they look a lot better than what you're showing from the ZS screen. I have no experience with Nikons, but with my Canons, there's no obvious difference in resolution or banding between high quality JPEGs and raw conversions as done by Photoshop.

--Rik

ChrisR
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Post by ChrisR »

Ah, thanks that makes sense. I'll check those and report back.
I tried reshooting, Tiffs. Slightly more exposure, and a completely different looking output :roll: . Time wasn't much different, at about 38 seconds per frame.

rjlittlefield
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Post by rjlittlefield »

One other thing to know is that ZS image display ignores color profile. If your inputs are not sRGB, then what you see in ZS will be different from what you see in Photoshop. Typically a non-sRGB profile will be wide gamut, which means that the ZS windows are liable to show low contrast and color saturation. But profiles are copied from input to output image files, so the final output should look OK in Photoshop et.al.

--Rik

ChrisR
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Post by ChrisR »

Though you're right, I can'r see jpeg artefacts as such in the camera output files, the tiffs are smoother and easier to work with. Edxra exposere made a huge difference too, though :oops: .

Back on the workflow question, how DO you guys convert from Raw to Jpeg/Tiff? My PC is slow so it's probably faster to expose to tiff in the camera.

(The red fiber above is in the blue square in a post I'm about to put in the Equipment section)

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