Magic Lantern Forum

Using Magic Lantern => Post-processing Workflow => Topic started by: AvarageJoe43 on January 16, 2015, 04:18:12 PM

Title: Dual-ISO : lots of artifacts in bright areas
Post by: AvarageJoe43 on January 16, 2015, 04:18:12 PM
Hello,

I'm having an issue with Dual-iso feature. Main problem is artifacts in bright areas and the image itself looks too grainy.  I've attached DNG files. Can I salvage it ?

Workflow:
1. MLRawViewer 1.3.3
2. cr2hdr.lrplugin (LightRoom)
3. After effects ACR (or Photoshop ACR)

Thank you in advance

http://www.filedropper.com/m14-1625000312  - not processed

http://www.filedropper.com/m14-1625000312-dualiso - processed

Title: Re: Dual-ISO : lots of artifacts in bright areas
Post by: dmilligan on January 16, 2015, 10:26:03 PM
Other than being extremely underexposed, I don't really see much wrong. Because it's so underexposed, you're pretty much only getting data from the brighter exposure (the darker exposure is just noise, so nothing can be recovered from it), so the "artifacts" and loss of resolution are to be expected. You can play with some of the interpolation options for cr2hdr, but I don't think there's much you can do. Next time make sure you ETTR (and only use dual-ISO if necessary).
Title: Re: Dual-ISO : lots of artifacts in bright areas
Post by: garry23 on January 17, 2015, 03:15:45 PM
@avarageJoe43

As hinted in the reply, from my experience Dual-ISO and A-ETTR are well matched bedfellows.

This short post may help you http://photography.grayheron.net/2014/07/consolidation-series-part-2.html