When camera captures DNG they are approximately 75mb in size. When update files in Adobe lightroom or transfer as DNG files shrink to ~45mb in size. Why is that?
The Leica S/S2 can shoot either a compressed or uncompressed DNG file. If you shoot an uncompressed DNG file it will be around 75mb in size. If you shoot compressed, that’s around 45mb. By default, Lightroom does not change the file size of a DNG, what you are probably seeing are files that you shot compressed.
Well,
I’m shooting uncompressed DNG files. They are 75 mb in size. If I import them in catalog as copy, size remained as 75mb. If I import as copy DNG or after files in catalog and I select update DNG metadata and preview or export to DNG files shrink to 45mb. Both versions of lightroom . 4.4 and 5 betaMy files also come in at 45MB and I am shooting uncompressed. I checked to make sure I was shooting uncompressed by looking at how many images a 32G card would hold which is roughly 400 images. If I then changed to compressed then it shows I can capture close to 600 images. As another comparison, I looked at the images I import from my Nikon 800 that I only shoot in raw but convert to DNGs on import and they show a little less than 45MB. I guess I’m not understanding something here. Can anybody explain?
If I shooting compressed what I never do, files ~45mb. But uncompressed 75mb. Only after Lightroom conversions or metadata & preview updated size shrunken to 45-47. The same situation with M9 DNG. From 18.3 to 8-9.
I believe I figured this out with the help of Tim Grey. I imported the same image into LR4 once using Copy and then once using Copy as DNG – it was shot uncompressed. Sure enough the file sizes were different (72MB vs 39MB) yet both had the same pixel dimensions (7512 x 4992). Additionally, if you opened each image in PS6 the file size in PS6 was exactly the same for both images. Apparently, when you import using Copy as DNG it uses a lossless compression. It certainly reduces the storage requirements but I for one will use Copy even though there should be no data loss on repeated openings of lossless compressed files. Call me paranoid!
So here is the problem. If Lightroom as well as Adobe dng convertor used compress format what is happens with different type of files when convert them to dng? Also you really can’t do metadata & preview update because files get converted to compress format. So how can save changes to dng except catalog?
You must be logged in to reply to this topic.