I shoot always raw (Sony .arw) with my A7RII but after a year there is so much disk space allocated.

A single uncompressed file uses approx. 80mb, so I decided to use the compressed format because there seems to be no big disadvantage.

Is there a software which could do batch conversions from uncompressed to compressed format?


1 Answer 1


It won't be an identical file to your cameras compressed option, but the free Adobe app called DNG Converter will compress it. The new file type will be .DNG, but it is still raw. DNG was proposed as a new universal standard, which didn't quite happen, but many raw editors likely will work with the DNG files. Experiment with just one file first.

Source and reading material: https://www.google.com/search?&q=adobe+dng+converter

  • \$\begingroup\$ and this might be even better than using the original compressed raws, as the sony raw compression is lossy \$\endgroup\$
    – szulat
    Aug 19, 2019 at 8:44
  • \$\begingroup\$ Thank you very much I overlooked this format. Do you also know a tool which can es used to crop DNG files? \$\endgroup\$
    – stacker
    Aug 19, 2019 at 12:16
  • \$\begingroup\$ Adobe's idea was that all raw software should support DNG as a universal solution. And most do, but you should test your raw software on one DNG conversion first, before fully committing. en.wikipedia.org/wiki/… \$\endgroup\$
    – WayneF
    Aug 19, 2019 at 13:10

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