Originally posted by falconeye But what are my options to get a smaller than 70MB file per K20D image? These 70MB are already compressed (lossless, LZW/ZIP).
I'd turn that around and ask another question: why do you need such a file? Why isn't having the processed RAW file good enough - why do you need a full resolution / losslessly compressed RGB version too? Usually, the only reason we need RGB versions of images would be to post online, to take to a third party printer, or to otherwise share with someone else. It's pretty rare that any of these applications would actually require a full resolution / losslessly compressed version of your images. Any images that are going to printed poster size, sure - but presumably you aren't doing that all that often, so it's shouldn't be a big issue to have 70MB versions of those few. And that's assuming 70MB really is the best you that can be done with TIFF lossless compression - have you tried all the different methods of TIFF compression - LZW versus packbits etc? Also, my understanding is that the PNG format offers one of the most efficient lossless compression schemes in the RGB world, so if your printer or client can work with PNG (not that common, but worth a shot), that might yield slightly better file sizes.
Still, I would assume tht the majority of your shots don't need to ever to saved in a full resolution / losslessly comrpessed RGB state. Assuming you've got a RAW processing program that remembers your RAW processing settings for each file (and if you don't, I'd say run, don't walk...), you would only need RGB versions of images you plan to share to share with others, and for most purpose, a reduced resolution JPEG should really be fine, shouldn't it?
Quote: - JPG (8 Bit only, bad 8x8 block artifacts if you use levels afterwards!)
Why wouldn't you be doing levels after converting to JPEG when you are shooting RAW? Ideally, you would be doing most of what you need to the original RAW data, and only certain operations would require work post-conversion. For files that you plan to process this way, then yes you might want a full resolution output file since the RAW file itself would no longer contain all the data necessary to regenerate the output as necessary. But since you're done editing at that point, again, JPEG should really be fine "most" of the time.