Question about RAW and DNG and TIF file formats. I have a Pentax K100D. I use Paint Shop Pro software. At the moment Paint cannot open the Pentax 100D RAW PEF files, (it can do *ist files however so I expect it in the future) so I have been saving as TIF's (using Pentax's Photo Lab) then playing with them. I can also save as DNG (using Pentax's Photo Browser) then open in Paint. RAW files are about 10.2 mb; DNG are about 11.4 mb; 16 bit TIF are about 34+ mb and 8 bit TIF's are about 17+ mb. First question is why do the TIF get up to 3x the size and where does that data come from? Second question, how much different is the DNG file from the RAW file? And last which of the two TIF or DNG would be the better for editing? Have mostly been doing highest quality jpegs but decided I wanted to have the negative, so to speak, so will be keeping RAW's and editing in something else. Thanks for any and all information.