I just learned that Nikon’s RAW file format uses lossy compression on most of their camera models, except for a few where you can choose between lossless compressed, lossy compressed and uncompressed. My very dear D40x offers no such option so I’m stuck with lossy, which brought me to ask myself, “what then is the point of RAW in the first place?” The compression is being referred to as “visually lossless”, so that although there is information lost you should not be able to notice.
So I did a read-up, which revealed that not only have more Nikon-savvy people than myself already looked into the matter, but their conclusion seems to be that it’s not as bad as it might seem.
Jeffrey Friedl writes about this in his blog entry “A Qualitative Analysis of NEF Compression”, where he puts lossy and uncompressed RAW to a rather thorough test which shows that you need to try very hard indeed to spot the difference. Lossy compressed RAW still offers a dynamic range far superior to FINE JPEG, leaving plenty room for adjustment and editing.
Besides, I mostly perfectly happy shooting in FINE JPEG anyway, like most hobby and home photographers, so I would say that the issue is really 99.9% irrelevant to the vast majority, including myself.
Other links that may be relevant:
- http://regex.info/blog/photo-tech/nef-compression (as linked above)