Consider JPG to be 8-bit for practical purposes. It technically supports 12-bit but most apps don't, so that's probably out. This is very broad & ultimately you're going to have to make the call yourself… getting the best bitmap possible in order to discard the original. This question is similar, but outdated as well as a slightly different use case - uploading duplicates at non-specified quality vs. Is there a reason for me to keep the images in NEF instead of converting them?.Should I just optimize for best images instead of closest to in-camera rendering? How can I do that without checking image-by-image that I like the result?.Logically speaking, wouldn't I want to convert to 16-bit JPEG or even HEIF/HEIC to get better quality at lower sizes? (NX-D only offers standard JPEG.).Is it just that I have gotten used to seeing the MacOS rendering of the images over the years, but the NX-D rendering is more accurate to what it must have been on the camera screen?.I was thinking the best option would be to batch-convert with Capture NX-D, but it seems to mess with the colors compared to the standard NEF preview in MacOS (some problems I've noticed are less vivid colors, lost detail, lighter shadows, and temperature changes). I'd like to batch convert them to a bitmap format to save space, and I want them to look as close as possible to what the image would have looked like on my camera screen at the time (as I was probably optimizing for that). It's been 8+ years without me touching them, so I don't see a reason to assume I will ever process and edit them. I have ~9k NEF photos from a Nikon D5000 that are currently taking up ~100GB.

Batch convert nef to jpg free