Originally Posted by Kris Deering
When I was helping Jim and Pat on the last big update to the tone mapping I was experimenting a lot with different things that showed there were limitations in highlights due to the "padding" used on the upper end to eliminate the chance for clipping/artifacts. I discussed with them the idea of doing a true "dynamic" tone map that enabled the user to adjust how aggressive to be when it came to the "pad" allowing the end user to vary a setting that would give more highlight pop at the expense of some possible artifacts (think of how a dynamic iris works and how more aggressive modes can sometimes show an artifact but give better results with blacks). DPad is exactly that. I've found that a level of 3 gives the best combination of highlight intensity with VERY little artifacts associated with it. 4 is also good and would give less artifacts at the expense of some highlight pop. 2 will likely show too many artifacts for most. 6 is about the same as what the DLev value of 8 was before, which is still quite good but I imagine once people have a taste of 3 or 4 they won't go back to 6.
As for the "adaptive feature", I reported some artifacts I was seeing to Pat to look at and they came to the conclusion that there is no way to eliminate them unless the Lumagen moved to an adaptive PER FRAME adjustment. This is now on by default and the default level is limited to a single adjustment per frame so that artifacts should be few and far between, if at all. There is a menu code that allows for further tweaking of this setting to be more aggressive, but I will leave that to Jim to decide if he wants to share that at this time. I haven't seen any artifacts with the default setting and it does help with the new dynamic modes, but moving to the next setting up (two adjustments per frame) does cause some very minor flickering at times depending on the scene (very similar to a quick flicker from a gamma adjustment in a dynamic contrast system).
So for this build end users shouldn't have to adjust any of their settings from before except that I would recommend they switch DPad to 3 or 4 to give better highlight results when watching content. Enjoy!
Originally Posted by Kris Deering
Here is some info on the new DPAD function. I generally use a level of 3, but 4 is quite good as well and will probably have less of a chance of artifacts:
DPad=1 generally slightly below peak so will see more clipping, but will be
brighter (IN MY TESTING THERE ARE TOO MANY CLIPPING ARTIFACTS WITH THIS OR A LEVEL OF 2)
DPad=3 generally at scene peak or slightly higher (OCCASIONAL ARTIFACTS IN VERY DIFFICULT MATERIAL)
DPad=4 generally slightly higher than scene peak up to a reasonable amount (ARTIFACTS ARE RARE)
of pad depending on scene
DPad=6 closest to current Dlev of 8 (IF YOU LIKED WHAT YOU HAD BEFORE THIS UPDATE, USE THIS)
DPad=8 more pad then current with Dlev of 8
I am updating my Setup & Calibration Tips document with the new DTM Pad, and wanted to be sure I have interpreted correctly what you posted above about the DPad settings. In the below, I am trying to explain what happens with highlight intensity, color saturation, contrast, and artifacts at each level of adjustment. I totally made up 5 and 7, since I did not find any posts about those levels.
Thanks for your continued efforts in improving DTM. I plan on sharing this information once I have finished editing.
▪ Below are explanations of what you may see as you adjust the DPad levels as explained by Kris Deering in this post and this post. The differences may be hard to see due to the per-frame adjustments made by the Adaptive feature.
• Level 1: Greatest highlight intensity, least color saturation and contrast, with too many artifacts. This is generally slightly below peak, so clipped whites may appear more often, especially in darker/mid brightness scenes with highlights.
• Level 2: Increase highlight intensity, decreased color saturation and contrast, but will likely show too many artifacts.
• Level 3: The best combination of highlight intensity (pop), a slight loss of color saturation and contrast, with minimal artifacts. The artifacts would only be occasional in very difficult material. This is generally at scene peak or slightly higher.
• Level 4: Reduced highlight intensity, increased color saturation and contrast with extremely rare artifacts. This is generally slightly higher than scene peak up to a reasonable amount of pad.
• Level 5: Reduced highlight intensity, increased color saturation and contrast with no artifacts.
• Level 6: Reduced highlight intensity, increased color saturation and contrast with no artifacts. It is about the same as what the Dynamic Level value of 8 was in the prior releases, which is still quite good.
• Level 7: Reduced highlight intensity, increased color saturation and contrast with no artifacts.
• Level 8: Least highlight intensity, greatest color saturation and contrast, with no artifacts.