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GXR P10 vs. CX4 vs. CX3 vs. CX2

Hi. DNG is a lossless raw image format based on TIFF. It is open and was introduced by Adobe. The abbreviation stands for Digital Negative.

Peter
 
DNG is almost universal and an open standard developed by Adobe but only seemigly used by Ricoh and Pentax and a few others - mostly low volume manufacturers. Adobe publicise their DNG specification which can be downloaded from their site for those that would like to see what information is packaged into a RAW file in addition to the raw pixel data off the sensor.

RAW is not as basically raw as many might imagine and the multitude RAW file versions are simply caused by differing interpretations by camera manufacturers of what extra information from camera/lens settings they wish to add to their sensor data. For example lens corrections can be incorporated there. The result is that the great mass of camera manufacturers have their own RAW file formats and quite often several of them.

Adobe obligingly make and distribute freely a DNG conversion program for almost every known format which technically translates the mutitudinal RAW file types back to a common base. But this program might not necessarily pick up every last little bit of information that was in the proprietary raw file. Obviously the DNG converter cannot "translate" across information into DNG where the DNG specification has not allowed a slot to receive it. Most obvious are individual lens software optimisations. Therefore a heavily corrected lens that looks perfect when processed out of a native RAW file format might not look quite as pretty when processed from a translated DNG file. But of course many RAW file processing programs would not be able to do any better without some serious help from the camera/lens manufacturer.

Ricoh have a nice touch in their GXR where those that know just how can adjust their MF lens characteristics in camera and store them in a Box/Mode file. Presumably these corrections are made before the DNG file is stored. If other camera manufacturers had any sense then they might do the same thing and use DNG. But is seems that by doing their own thing the various manufacturers can increasingly lock in their loyal acolytes to not only the lens that only works on their mount but its performance is also strongly linked to using their RAW file format as well.

I hardly classify myself as an expert of RAW file formats so if anyone can help or correct me then feel free to do so.

Tom
 
Even Adobe can be slack in producing colour profiles for those that use the DNG RAW file format as the GR "Red's" debacle showed.

Tom
 
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