Hi all, quick question regarding Filmic’s middle grey slider. Correct me if I’m wrong, but as far as I understand it, the middle grey slider is somewhat analogous to the exposure module, but for it’s position in the pipeline. Exposure needs to be set earlier in the pipeline, so that subsequent modules work right.
That said, is there any downside to using it for final minor exposure adjustments? Since the arrival of diffuse and sharpen, I’ve often used several instances of the module in my edits. I frequently edit on a slower but portable computer. If I have 2-3 instances of diffuse/sharpen, denoise profiled, color balance rgb, tone equalizer… and I modify the exposure module, it takes quite a while until the image is updated. I assume that’s because the change in the exposure module has to be fed to all the modules that come after. If I do it via the middle grey slider in filmic, the change happens almost instantly.
TLDR: Exposure for main exposure adjustments, filmic middle grey for final minor exposure changes once edit is finished for performance reasons. Pros/cons?
no there’s no downside if the result is ok for you. It depends on your edit: if you made much use of parametric masks, changing exposure later might have some side effects - so using the slider in filmic late in the pipe might be the more comfortable way to do late corrections.
Hadn’t thought of parametric masks, but it’s also helpful there. I guess my question was filmic middle grey slider vs additional exposure module moved right before filmic in the pipeline. Are they the same?
I am not 100% sure but I think DT caches by default the current module when using opencl and so when you are changing it in filmic as part of a filmic edit maybe it is faster whereas going to exposure fires the whole pipeline?? Or maybe this has nothing to do with it…I think if you have the memory you can cache the whole process in opencl…all this is conjecture on my part and just based on some settings that I have seen in darktablerc config file…Someone more knowledgeable can likely comment
EDIT:
This was the passage I had read but as I said it might not be relevant
opencl_synch_cache
This parameter, if set to “true”, will force darktable to fetch image buffers from your GPU after each module and store them in its pixelpipe cache. This is a resource consuming operation, but can make sense depending on your GPU (including if the GPU is rather slow). In this case darktable might in fact save some time when module parameters have changed, as it can go back to some cached intermediate state and reprocess only part of the pixelpipe. In many cases this parameter should be set to “active module” (the default), which will only cache the input of the currently focused module.