carstenw Posted October 5, 2009 Share #41 Posted October 5, 2009 Advertisement (gone after registration) Hmm, doesn't seem to work for me. I select an image, 10.3MB standard Leica DNG, change the White Balance to Fluorescent (which it is not!), and then try to update. Nothing... LR 2.5. Doesn't matter if I am in thumbnail view, full view or edit mode. EDIT: don't mind me, I am just being incompetent. The 10.3MB is actually 10.3MP, and the size has gone down. Thanks for the tip! Link to post Share on other sites More sharing options...
Advertisement Posted October 5, 2009 Posted October 5, 2009 Hi carstenw, Take a look here M9 - compressed / uncompressed DNG - who's using what?. I'm sure you'll find what you were looking for!
lars_bergquist Posted October 5, 2009 Share #42 Posted October 5, 2009 Does storing in 8 bits or 16 bits has a chance of provoking an allergic reaction or worse? If not, I'm not sure your comparison is really pertinent. It is pertinent only if you think evidence is more valuable than off the cuff opinion. This is of course eminently true in the field of medicine. In that of photography it is seldom a matter of life and death. Some of us do nevertheless retain a soft spot for evidence. I am of course old-fashioned/obsolete/paleozoic. Imagine, I can remember when there were no TV commercials! The reason why I feel evidence is more valuable is that it relates better to reality -- but reality is just another obsolete notion, unmentionable in some academic circles. The dour old man from the Age of Evidence Link to post Share on other sites More sharing options...
t024484 Posted October 5, 2009 Share #43 Posted October 5, 2009 It is quite obvious to me that the compressed picture has more noise than the uncompressed version. Look at the crop of the lamp in both versions, and look at the noise on the surface, but even more, see how much sharper the edge of the lamp is. Compressing 16.384 levels to less then 256 ( because of the black level offset) and then back again, leads to adding noise to the picture. With this compression algorithm that Leica is using, it leads to roughly 1/2 stop more noise at low ISO values, but is completely vanishing at high ISO values. So If you shoot at 2500 ISO, the compression noise will be invisible, but not in this very example. Hans Link to post Share on other sites More sharing options...
hoppyman Posted October 5, 2009 Share #44 Posted October 5, 2009 Hmm, doesn't seem to work for me. I select an image, 10.3MB standard Leica DNG, change the White Balance to Fluorescent (which it is not!), and then try to update. Nothing... LR 2.5. Doesn't matter if I am in thumbnail view, full view or edit mode. EDIT: don't mind me, I am just being incompetent. The 10.3MB is actually 10.3MP, and the size has gone down. Thanks for the tip! Excellent! It drove me crazy for a while. I first found this function in ACR then the particular preference disappeared with an update. I could never find where it wennt from Adobe. I did get it working again there too. In any event, it is a big space saver. Link to post Share on other sites More sharing options...
robsteve Posted October 6, 2009 Share #45 Posted October 6, 2009 OK this could get messy! If you process a DNG in LR selecting the Adobe M9 18 Sep profile then open it in C1 you cannot choose any profile other than 'embedded'. I think this is similar to what I was experiencing with my DMR files that were compressed with the Adobe DNG converter. Robert Link to post Share on other sites More sharing options...
CheshireCat Posted September 5, 2014 Share #46 Posted September 5, 2014 Resuming this thread after 5 years I am a bit disappointed about the test images not being available for download anymore Would someone please provide the same (or different) pair of test images for me to test how well they can survive postprocessing ? I will share my findings. If you want to provide a new pair, my preference would be an ETTR landscape with smooth gradients in highlights (clouds, sunset, or similar), ISO 160. Thanks ! Link to post Share on other sites More sharing options...
dresser Posted December 7, 2015 Share #47 Posted December 7, 2015 Advertisement (gone after registration) I've actually just sent an email to Leica support to ask about this to see if there was anything Leica M9-specific about the compressed vs uncompressed debate. Before sending that email, I googled the DNG specification and found article about DNG on wikipedia suggesting there are lossless and lossy types of compression. The article references this discussion on lossy vs lossless compression which concludes that there is virtually no distinguishable difference between compressed and uncompressed files. BTW that article was based on tests with a Nikon D750, but I'm sure the conclusion would be exactly the same for an M9. Link to post Share on other sites More sharing options...
tobey bilek Posted December 10, 2015 Share #48 Posted December 10, 2015 compression is data loss, no way around it. No way to recreate what is gone just like JPEG. Storage is very cheap. 2 guesses what I use. Never tested. Link to post Share on other sites More sharing options...
pop Posted December 11, 2015 Share #49 Posted December 11, 2015 compression is data loss, no way around it. No way to recreate what is gone just like JPEG. This is simply not true. There are compression schemes which do lose data and then there are schemes which do not. The former are called "lossy compression", the latter "lossless". Link to post Share on other sites More sharing options...
rapids41 Posted December 11, 2015 Share #50 Posted December 11, 2015 I have done a few quick tests comparing uncompressed DNG and lossy compression in Lightroom. I have not seen any difference. So now I am converting every compressed DNG from my M9 with lossy compression in Lightroom and saving a lot of disk space. Link to post Share on other sites More sharing options...
pico Posted December 19, 2015 Share #51 Posted December 19, 2015 compression is data loss, no way around it. Fortunately there are many loss-less compression methods for our purposes, and the link shows only a partial list. Aside: photoshop .psd is compressed, and in TIFF we can specify LZW which is effective. Link to post Share on other sites More sharing options...
pluo Posted December 20, 2015 Share #52 Posted December 20, 2015 The question is very simple: "Is M9 DNG compression lossy or lossless?" Over years of discussion in this thread, I do not see anyone gave a yes-or-no answer. Link to post Share on other sites More sharing options...
pop Posted December 20, 2015 Share #53 Posted December 20, 2015 The technical data sheet says this: DNG™ (raw data), choice of uncompressed or slightly compressed (by non-linear reduction of color depth), 2 JPEG compression levels. Hence, you lose some colour information but - as far as I know - no one has yet demonstrated that the difference was visible. Link to post Share on other sites More sharing options...
may1029 Posted December 23, 2015 Share #54 Posted December 23, 2015 32g SD card, therefore I use uncompressed raw files. Do not want to lose any information this gorgeous CCD generated, even the difference may be invisible. Link to post Share on other sites More sharing options...
sblutter Posted December 25, 2015 Share #55 Posted December 25, 2015 I use jpg's for 'snapshots', family etc. For serious (hopefully!) work that may be printed, uncompressed. Why not? Hard drives are now massive Link to post Share on other sites More sharing options...
Tom Johnston Posted December 30, 2015 Share #56 Posted December 30, 2015 I posted this reply to the thread on B&W, and in the spirit of sharing info on this thread submit some of my working method. My usual practice is to shoot raw, DNG only (uncompressed), and convert to b&w in C-1 or PS, but recently I decided to include "jpeg fine" b&w in my set up. I was inspired to do so because of a series of images I was going after. I was excited by the out of camera jpegs which needed little tweaking. A few days later I decided to have a look at the DNG files and convert to b&w; to my surprise I found more detail especially in the higher values. I'm most pleased with C-1 (9) as my raw converter with additional adjustments in PS (CC2015). I posted some of the b&w images from my M9 and a few color images from another camera on my website for anyone who would like to have a look. http://www.arttaj.com/moving-waterorwater-water-everywhere/ Link to post Share on other sites More sharing options...
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