I’ve been a long-time Lightroom user, recently looking at whether I should be moving to Lightroom CC, or Apple Photos or RawTherapee. I use all this software on a MacBook Pro with 2560x1600 resolution.
Loading up a Nikon NEF file in RawTherapee, I’m finding that the images displayed by RT is fuzzy at all zoom levels compared to the same image at the same zoom level in the other apps. Is this normal?
Take the below image for example. This is a piece of towel rendered in RawTherapee:
The same NEF file, same piece of towel at a very similar zoom in Apple Photos:
The latter image is clearly much more clear. Playing with sharpening doesn’t help. It’s not the processing of the image but the actual rendering to the screen that’s not taking advantage of the full screen resolution. You can confirm this by zooming into the above images and seeing larger blocks in the RT version. The first time I saw the RT version, I thought my eyes had gone bad. But it’s just the rendering that’s in RawTherapee.
What you’re experiencing is a cocktail of confusion on several levels:
Don’t do this test using raw images. A raw image cannot just be shown, it must first be cooked. It’s like a refrigerator full of raw stuff and a recipe, it’s not a ready meal. Lightroom’s interpretation of a raw image is different to RawTherapee’s interpretation, Lightroom does a bunch of stuff to the image by default including sharpening which RawTherapee does not do by default. That’s why you should perform this test using a non-raw file.
RawTherapee’s sharpening and noise reduction tools only affect the preview at a zoom level of 100% or more.
RawTherapee is not HiDPI-ready, i.e. none of us developers have HiDPI screens and so it probably doesn’t perform optimally on such screens. When I simulate a HiDPI screen using scaling, everything in RawTherapee including the thumbnails and main preview are also upscaled.
Scale=1