Archived posting to the Leica Users Group, 2014/07/02
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Mark you don't have that right. Nothing 'half assed' about it. A DNG file is a true raw format file. The structure of the file is like a TIFF but with instructions. That is to say the RGB information is the same but the developing instructions are not actually applied, just recorded. So you can go back and change those instructions with no loss of info (the same as with other raw formats). You can choose to convert NEF (or other raw formats) to DNG if you want but you can't go the other way. At least I never heard of that. Cheers Geoff http://www.pbase.com/hoppyman On 3 July 2014 15:18, Mark Rabiner <mark at rabinergroup.com> wrote: > Though a "DNG is both a raw image format and a format that supports > "non-raw", or partly processed, images" > Nothing Raw about a Tiff. > A DNG can be converted to say a NEF which is the digital Nikon raw format. > A thing I needed to do when I first got my D40X. > They converted to full RAW. Not some half assed thing. > > > On 7/2/14 5:16 PM, "Geoff Hopkinson" <hopsternew at gmail.com> wrote: > > > Howard a DNG is essentially a TIFF with some more instructions. > > > > > > Cheers > > Geoff > > http://www.pbase.com/hoppyman > > > > > > On 3 July 2014 06:41, Howard Ritter <hlritter at bex.net> wrote: > > > >> This file-size difference is intrinsic to TIFF, which interpolates a > value > >> for all 3 colors, R-G-B, for each pixel. > >> > >> The X-Pro 1 has a 24-Mpx sensor, 8 million for each of R, G, and B (this > >> is simplified), each of which generates 1 byte of luminance > information. So > >> its raw (adjective, not acronym!) file size is 1 byte x 8 Mpx x 3 > colors--to > >> a first approximation, 24 MB. If JPEGed for storage, it is re-expanded > when > >> viewed. When the image is viewed or printed, software gives each R > >> photosite also a G and a B value by interpolation from adjacent G and B > >> photosites, and likewise for native G and B photosites. So the full > image > >> you see in Photoshop should have a file size of ~72MB. TIFF is simply > this > >> full file, with interpolated colors at each pixel. That's why it's > always > >> generally about 3 x the size of the stripped-down raw file. Differences > >> seen in practice may result from compression, which can save significant > >> storage capacity without loss of information (unlike JPEG). There may be > >> some housekeeping stuff that brings your TIFF file to 4 x your raw; > perhaps > >> the file also incorporates a separate raw image. > >> > >> I don't know how this relates to DNG, though. > >> > >> --howard > >> > >> > >> On Jul 2, 2014, at 1:58 PM, Ken Carney <kcarney1 at cox.net> wrote: > >> > >>> I hadn't really looked either. My X raw files are about 24-27 MB (not > >> sure what causes the size differential), opening to 94MB Tiff's. My > Canon > >> 5D MkII files are roughly the same raw size, but open to 120+ MB Tiff's. > >>> > >>> Ken > >> > >> _______________________________________________ > >> Leica Users Group. > >> See http://leica-users.org/mailman/listinfo/lug for more information > >> > > > > _______________________________________________ > > Leica Users Group. > > See http://leica-users.org/mailman/listinfo/lug for more information > > > > > -- > Mark William Rabiner > Photographer > http://gallery.leica-users.org/v/lugalrabs/ > > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information >