Left side - the result of downscaling the image from 1800px (height) to 1200px in the Mac OS Image Preview utility. Right side - the same downscaling in Photoshop (Menu: Image->Image Size...) You can see significant visual distortions of the photoshop version. How can I avoid this weird behavior?
UPDATE: OK, I've figured out that it happens only when scaling PSD, when I save unscaled image as PNG, and then re-open and downscale it in photoshop, it works perfectly! What's wrong with scaling in PSD?