Hey, what is the best way to share unedited raw files without having to actually upload every .raw image... Can't they be edited off of jpg previews or something? Most cap out at 2gb. I have 5gb of photos my client wants to be able to edit from raw form but I have the photos as I took them...
@WobertC that is exactly right. A smart preview is a lossy compressed dng file that has also been scaled down to have a maximum of 2540 pixels on the long side. You can export any raw file to a dng with lossy compression from Lightroom Classic. I think if you do not scale but only check the lossy compression, it will even retain the Bayer mosaic.
For example I just tried with a Z7 NEF file that was originally 76.8 MB (14 bits using lossless compression in camera). The image is 8256x5504 pixels. It is a ISO 25600 image of an owl before dawn so lots of noise which is hard to compress.
Plain lossless compressed DNG (camera raw 12.4 compatibility with medium preview): 64.7 MB
Lossy compressed DNG: 47.4 MB
Lossy compressed and scaled to 2540 pixels (smart preview): 3.6 MB
So you can gain about a factor of 2 in this case with just lossy compression. Going to smart preview gains a factor of 20.
A much less noisy image of a sunset (so simple subject) taken at ISO 100 with the same camera was 54.2 MB in the NEF
normal dng: 43.1 MB
lossy full size dng: 11.6 MB
smart preview: 1 MB
So subject matter matters. Here we have a factor of 5 gain from just lossy compression which is not noticable in this image at all. Going to smart preview gains you a factor of about 50. So in general, just lossy compression on the dng can gain you between a factor of 2 and 5 in size.