Here is my file for which LMMSE performs better with the AsShot WB compared to RT’s auto-WB: http://filebin.net/zndesgrh1e
Well, in fact the temperature/tint corrections finally boil down to RAW multipliers… so setting the multipliers directly is just another way of doing the manual WB correction, if I’m not wrong.
As far as I can see, with proper WB multipliers I’m getting nice results with LMMSE on linear values. But I’ve not experimented much so far.
Can you share these proper WB multipliers ?.
@ilias_giarimis: For this specific image, AsShot multipliers are OK. I’ve played with RT some time ago, disabling the auto-WB computation and replacing the auto-WB multipliers with the AsShot ones, and results where practically the same as in PhotoFlow, and definitely less noisy than the default RT processing.
I’m searching on my disk to see if I still have the examples.
OK … it is again wrong auto_wb because it wrongly tries to handle the yellow which fills the frame. The AsShot is a correct WB here. But I think this is an exception ?. I find more shots where the as shot WB is
So the problem is to find an algorithm which does not fail that easily, I had some links for more robust algorithms … I will try to find them again …
I’m still of the idea that the WB a user would choose is as good as, if not better, the output of any auto-WB algorithm.
Unless the user sets intentionally the WB far off for artistic purposes…
Ideally you’d set the WB locally…
This is not very difficult, but still it is more practical to have a global WB before the demosaicing and then local corrections after demosaicing but before converting from the camera colorspace to the working colorspace… particularly because at this stage it is already possible to construct luminosity masks and/or hue masks.
… or unless he shoots with UniWB technique or he forgot to change to a correct WB or the in camera auto WB fails etc
Thanks, is it possible to provide very overexposed shots (say +5EV so that all channels at all the frame are clipped) at ISO100. To detect any non linearities at highlights …
This is complicated with the way RT is organized. Going back and forth from RAW to RGB perplexes things regarding white level and chanell scaling, I remember Anders had difficulties adapting …
Thanks a lot for all your input. I am definitely less worried now. I thought, I had been using wrong settings for previous NEF-images. Actually, the extreme illumination in this particular case, challenges the software probably causing artifacts.
I would very much like to help you with overexposed shots for further investigation. However, the shot was taken at a building illumination event and there is no option to reproduce the scenario.
No need to replicate the same illumination, any normal illumination is fine although for this case I would prefer tungsten …
Hi Ilias, I found a tungsten light in cellar. D700, ISO 100, +5EV directly shot into tungsten light, not completely clipped 
OK thanks, downloaded both …
No surprises here … but I detect differences from body to body … according to claudio’s D700 the WL would be safer to set at a bit lower (i.e. 15650 insted of 15750) . But this is not the reason for our artefacts (as we can see by increasing raw linear correction at 1.01 …). I also detected a small green inbalance but setting green equalization at 3 things get worse
I’ll come back later with screenshots …
@heckflosse Ingo, can you try to change the pre_WB calculation ? I think Anders left a switch (-1) to disable the calculation and use AsShot intead …
Ilias, I’ll try 
