Archived posting to the Leica Users Group, 2012/12/09
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Herbert you have several items in there. Firstly if you use compressed DNG set in camera you give up almost nothing to gain the savings in file sizes. Some argue that you cannot see any difference at all. While it is technically lossy, this does not mean the change is significant and there is no futher loss on resaving, unlike where you save new versionsa as new JPGs.. Secondly on import in an Adobe raw processor (ACR or LR) truly LOSSLESS compression is applied. In recent program versions that is the default (and now only) process because there is no downside at all. If you open previously uncompressed on import DNGs and do some editing, for example a WB change that LOSSLESS compression is applied. Thirdly , whether you originally shot with your camera set for compressed or uncompressed DNGs, those files are further losslessly compressed by the Adobe program on import (or first editing and saving for earlier program versions). Cheers, Geoff http://www.pbase.com/hoppyman On 10 December 2012 06:39, Herbert Kanner <kanner at acm.org> wrote: > Hi LUGers, > > I'm looking for some enlightenment from anyone who knows. The question has > to do with the size of Leica DNG files. Back in August, 2010, I had a set > of DNGs all but one of which were 36.4 MB in size. All of those taken the > same afternoon at the same general location. Similarly, using Leica's > compression, in December, 2011, I found a set of DNGs taken the same day, > at 18.3 MB. > > Then, in November, 2011, there was a set taken the same day, where the > file sizes varied from 19.6 to 23.1 MB. Was this a result of a firmware > update in which Leica probably introduced LOSSLESS compression? To round up > the picture, I found a set in August, 2012, where the size range was 8.5 to > 10.3 MB, undoubtedly where I set "compressed DNG" on the camera. > > > > Herbert Kanner > kanner at acm.org > 650-326-8204 > > Question authority and the authorities will question you. > > > > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information >