I'm finally able to revisit this thread...
To reiterate, it appears there is some mojo that other tools have that RT lacks when it comes to dealing with extreme highlights. While each tool has a different default render profile, it appears RT posterizes the output in extreme highlight areas, and this is virtually impossible to get rid of. Here are some samples, each 1:1 zoom to the same area in the image
1. RT: note the posterized yellow bands:
2. Aperture
3. Capture One
4. LR 4
As you can see, the RT render has a distinct yellow/green cast and the transitions between these deep yellow areas and the white blown regions in the clouds looks posterized (for lack of a better term). As you can see below in the image from RT showing only the green channel, the yellow/green areas in the clouds appear to be directly correlated to the blown areas in the green channel:
Here is the same RT image with highlight alert turned on:
For reference, here is a screenshot of the RAW histogram:
I have also posted the CR2:
http://ppmax.duckdns.org/public.php?service=files&t=2580a5573701cb3ea9b53ea234f1b7d6To combat this effect I have tried everything:
Highlight reconstruction (all modes); luminance recovery *kinda* works but it's virtually impossible to get rid of the yellow/green cast and the banding
Highlight compression (several different values)
Lab adjustments (reduce a and/or b)
White point
RGB curves (lowering green channel output, and/or bumping blue and red channels)
CL curves (see above)
Different demosaic algorithms
...etc
It appears RT has a strange behavior (bug?) when it comes to rendering images that have blown or nearly blown highlights.
Any clues about how to fix, or what may be causing this? Clearly, from the images posted above, RT's render is the strange one of the 4 tools...
thx much--
PP