Saturday, April 13, 2013

DNGMonochrome 0.9.71 beta released

It's a bit of an intermediate release, not planned, and mainly fixes some problems with the algorithm.

  • Fixes the 'maze' artifact on M8 and M9 conversions. This problem showed mainly on M8 photos and in brighter red areas of M9 photos. On the M8, the artifact was visible at 200% magnification with sharpening set to at least 20%. Incorporating the BayerGreenSplit value in the algorithm solved the issue. On the new M and the Canon conversions, the artifact didn't show (the BayerGreenSplit value on the M is 50 - for the M8 and M9 it's 500 - and on the supported Canons the value isn't registered at all when converting CR2 files to DNG).
  • Fixes the few artifacts left when using the 'sharper' setting. Due to the implementation of the BayerGreenSplit value, the 'sharper' setting has less effect now on M8 and M9 photos (compared to previous versions). These artifacts were only visible at 300 to 400% magnification, mostly on highlighted edges.
  • Fixes several smaller bugs that might have had a negative impact on the RAW and RGB conversions.

A note in general when using Lightroom: when importing monochrome DNGs, Lightroom will default to the settings of your color DNG. For sharpening, this default setting might be too high. DNGMonochrome concentrates on sharpness and resolution, and the produced DNGs need less sharpening than the Lightroom color versions do. Make sure to cast an eye on this setting if you think the DNG looks gritty, too noisy or too sharp.

You can download the new version of DNGMonochrome here.


  1. Hello, I've been trying to solve this problem myself for a while now and I'm stuck. I can't figure out how to use the BayerGreenSplit value prior to the demosaic, mainly because it has no units. If you could point me in the right direction or give me an idea of what to do, I'd really appreciate it. Thanks for your time.

    1. Hey Eddie,

      I haven't really solved the issue of the value itself. Someone I've been talking to has pointed me to some info on the subject, which seems to indicate that Adobe dropped it. Apparently 'bigger than 0' now just means there's divergence, but the value itself doesn't seem to have a purpose.

      If it still has, I think it's probably only useful to Adobe itself, in their handling of it in ACR / Lightroom. My idea now is that the value has been more useful for camera makers in conjunction with Lightroom, than for people like you and me trying to interpolate those photos (since we don't have access to the Adobe code that handles the value).

      If you send me an email at I can elaborate a little bit on the subject and how I tried to solve it.