Of this batch of photos, 90% of them fall within 29-36 MB but that’s still a much wider range. I’m actually surprised at your quoted range being so narrow, as I find scene complexity can make a significant difference. The 43 MB example had almost the entire frame covered in very fine netting. The 22 MB example was mostly dark with a couple of large blown out lights. I derived those numbers from my April 2019 photos which were mostly taken of all manner of subjects in Singapore (instead of mostly aircraft any other time). My 24 MP DNGs range from ~22-43 MB, averaging at 33.2 MB. I would be very interested to know what size DNG you would get if you converted an X3D file using Adobe’s DNG Converter application - it’s free and I don’t think it needs an Adobe account. Or perhaps they’re just being incredibly inefficient in recording the sensor data. My suspicion with the sizes you have shown is they are trying to demosaic the data in-camera, which means it’s not really RAW but a linear DNG. I have no idea what wild scheme Sigma have come up with, but it is not something that can be blamed on the DNG format. By design they should be approximately the same size. In the end, I have ~24 million red, green, or blue values stuffed in one file or the other. That wrapper should describe the sensor characteristics in order to understand the data. The whole point of DNG was to provide a generic wrapper around the sensor data. The reason my PEF and DNG are so close in size is because the same data is included in the files. I stand by my assertion that DNG does not mean larger file sizes than native. The concerns over Linear DNG size and “keeping originals” are two separate things. Linear DNGs obviously carry a massive penalty of size but they cannot be said to be “originals”. The original version delivers excellent results, combining demosaicing and denoising into. Where before you had 12 bits of red or green or blue you now have all three - 36 bits per pixel, three times the data, and therefore approximately three times the file size.ĭNGs that come from the camera, or DNGs which are converted processing-free from PEF/NEF/CR2 etc (such as by using Adobe DNG Converter, or Lightroom), do not carry any real penalties in size. DxO has announced DxO PureRAW 2, the latest version of its impressive app for pre-processing RAW images. They contain 24 million full colour pixels as a result of the demosaic process and other corrections. These are no longer “sensor dumps” which contain, say, 24 million pixels, each of which is red, green, or blue. ![]() Linear DNGs exported from PureRAW or PhotoLab will approximately triple in size because they contain triple the data. This also explains why DNG has “no better quality” than a native RAW - because the quality is identical. This should come as no surprise as they hold the same amount of sensor data, which is by far the largest contributor to file size. A PEF and DNG are very close in file size for any given shot. My Pentax is set to record DNG - a decision I made many years ago when upgrading to a camera that could write them in approximately the same time as a native PEF file. ![]() I’m not sure where DNG gets this reputation for enormous file sizes.
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