Compare photos (with zooming function) on the new lighttable-expose function
Many users ask for improvment on comparing photos functions on darktable. For example, comparing the sharpness on macro photos or some near photos of animals quickly. I just discovered the new expose view on lighttable and this new view is certainly the perfect view to implement that. Actually we have to go on darkroom, make snapshot of one photo and go to the other to compare, or quickly switch on a photo to the other with ALT+Z or CTRL+ALT+Z function. Not the best and quick way to do it.
The function I propose would be the possibility to zooming (to 100% max) on a point of photo and have the other photos zooming automatically the same way on the same part. Of course, sometimes the point we would see on a photo is not totally on the same part of the image. So an option to move the part where we zoom on each photo separately should also be added. Of course, the frame size of each photo keep remains the same. It's inside we zoom on a part. Maybe this function should be limited on 3 or photos max, to keep memory and CPU usage great and also have sufficient space to have decent images sizes.
If a developer want to implement that, it would be great.