RT displayed images on Retina Mac fuzzy?

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.

Is there a way to fix this?

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What you’re experiencing is a cocktail of confusion on several levels:

  1. 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.
  2. RawTherapee’s sharpening and noise reduction tools only affect the preview at a zoom level of 100% or more.
  3. 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.


Speaking of which, I would like to see two screenshots from you:

  1. A screenshot of your system settings where you control DPI and scaling, that seems to be in the Apple menu > System Preferences > Displays.
  2. An uncropped screenshot of your whole screen with RawTherapee maximized using the settings from the same DPI/scaling settings.

Hi Morgan,

Sure, happy to help. Totally understand that if the hardware is not available, it’s difficult to test.

I took another image off the Internet, a JPG, to remove the “cooking the raw” piece of it. You can find the original image here: https://i.kinja-img.com/gawker-media/image/upload/t_original/b0mr8r0pi47ydytwgb1y.jpg

My computer’s display settings (admittedly not telling much):

This basically says 2560x1600. The screen is scaled 2x as is the default for all Macs.

The RT full screen image:

The Apple Photos full screen image, for comparison:

And then, zooming in on the two above images, you can see the difference:



as Morgan wrote, RT has basically no support for hidpi at the moment, unfortunately… :frowning:
darktable should work though!