Query about DNG conversion

[Gene]

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I just got an M8, which I'm enjoying immensely, and am learning to use it, and I hope some of the other forum members will be able to answer a few questions as I go along. My question at the moment has to do with DNG files. I have Adobe's DNG converter, which I've used previously to convert D2 RAW files to DNG. For some reason at one point I found I couldn't get Capture One to recognized some M8 DNG files (I think because I had used Camera Raw to do a batch name change on them). So I tried running them through the Adobe DNG converter to see if that would restore them to a form Capture One would recognize, which worked. But what I'm curious about is that the converted DNGs (now labeled .dng in lower case) are only half the size of the originals. I've tried examining them both under high magnification in Capture One and I can't see any visible difference in the files.

 

Does anybody know what the conversion actually does to cut the size so, and if it has any deleterious effect? If it doesn't, it might helpfully cut down on the amount of storage space needed. But I hesitate to lose anything that might affect picture quality.

 

-Gene

[stunsworth]

Hi Eugene, they're losslessly compressed - a bit like Zipping them.

[Paul_S]

Eugene, as Steve said, the DNG Converter compresses the files, using a lossless algorithm. So no information gets lost. Note that some raw converters do not read compressed DNG. In my experience, Capture One 3.x does not, but 4 (beta1) does. Do you use Capture One 4 beta?