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Talk:LDR / HDR - Workflow case E

Hey, a few people have complained about the quality of the documentation, and I too am a bit confused, so I'd like to point out and ask some things:

Stack levels

"In the Group settings, Detection tab, select the detection as follows, One stack level and Use hard links for a stack:"

Are there any image quality issues if we do not?

I'm thinking of the problem where the blending border is not placed in the same area between two images when you compare the rendered -2, 0 and +2 layers. From what I understand, if APG places control points in different places in each layer then the blending border wont be in the same place, but if we set APG to only place CPs in one layer, and to hard-link the others, then the blending border will be identical. Is this correct?

Color correction by layers

"In the Group settings, Panorama tab, uncheck the color correction by layer and select the type of correction: Exposure (best suited mode to bring all the images into the same HDR space)."

Why do we not want color correction by layer?

This is the pano preview with color correction by layer: http://i.imgur.com/CxWpL.jpg

This is the pano preview without color correction by layer: http://i.imgur.com/xXPFY.jpg

Clearly the pano preview looks better with cc by layer enabled. The yellow anchor photo does not blend in with the others at all in the without screenshot . Why then does the wiki say to turn it off? Or maybe the rendered output is better without cc by layer and the preview is wrong? (I haven't had the time to test-render as this is quite a big pano).

--update I ran some tests, and when using cc by layers and exposure fusion, half of the photos in the middle row (49-36 in the screenshots) became very dark, completely ruining the pano. I don't know why, they all have the same parameters, and all have intact Exif. Unfortunately I already closed APG without saving, but here is a screenshot of the resulting HDR file where you can still clearly see the problem: http://i.imgur.com/ilWbo.jpg

The only way I could get APG to render a correct high dynamic range RGBE or EXR was when I turned color correction completely off. Please confirm whether this is really the only way to do it. http://i.imgur.com/bE19L.jpg

Fusion tool

The next section tells us about the fusion tool. Why? This is the LDR->HDR workflow, I thought the fusion tool could only produce LDR output, so why mention it here?

Output format HDR(RGBE)/EXR

Do not forget to choose the HDR Radiance output format (.hdr).

Why not EXR? Does APG only correctly support Radiance-RGBE? If it supports EXR too, the wiki should explain the difference and say that both are fine (up to the user) instead of dictating one with no explanation.

--update EXR files looked identical to the HDR ones, even after tonemapping them.