Komodo-X - highlight recovery

[Patrick Tresch]

Hello,

I would like to speak about a problem with the highlight recovery from Komodo-X (and probably also other RED cameras which have this recovery feature).

This feature is really cool and you gain more than 1 stop of highlight recovery on the expenses of color accuracy but retaining white details. Really useful for bright skies with white clouds for example.

BUT...

The recovery isn't perfect as it's going from color highlights, to no infos present (dead zone) in the picture, to white recovered highlights infos. It passes through a type of dead zone which breaks the smoothness of the recovery. If you want to test it out you can make a shot well overexposed and close down the lens by 4 stops, then in post, push the curves to gain details close to the breaking point of the highlights and also push saturation. You will easily see it on your RGB waveform. It's effectively pixel-peeping but I was curious to see what effect it hand on the recovered highlights.

Would it be possible to have a better RAW processing to get closer to a smooth transition?

Thanks

Patrick Tresch

 

[Adam Langdon]

I would treat it as one does with Highlight Recovery on BRAW files from Blackmagic. Sometimes it works well, other times it makes it look worse.

 

[Patrick Tresch]

What do you mean by sometimes? Depending on what? How would you treat it?

Pat

 

[Adam Langdon]

What do you mean by sometimes? Depending on what? How would you treat it?

Pat

using your own judgement. There's times when the HR option creates an obvious orb in the sky or blob and sometimes it just looks right. I edit/color in Davinci Resolve and find Highlight Recovery to usually work, but not always.

 

[James Sielaff]

Calling it "highlight recovery" is one of the more misleading naming conventions.

it isn't good for recovering, but does do well with softening the clipping point or adding details to clipped regions, but it doesn't help in pulling the exposure back in grading. it is just a grey blob with all the tonal richness straight out of SNES game play.


Great for holding faint details in the extreme highlights. like burnt out backlight on hair, or objects outside of a mostly blown window. it just gives those whispy highlights a sense of being more organic and analog. But they aren't there to be pulled back. their almost worse at recovery than without. "Highlight-X" or HLX might be a better term. not sure what Red officially calls it.

I'd be curious if someone has figured out an elegant solution for using it as a recovery option, but for me it is a lot of meticulous and annoying grading and roto style hacks to make it barely work sometimes. so i just don't count the extra HLX stop if i intend to pull anything back or have anything near clipping on a face - like action films where the character might be sweating and parts of the face are reflective enough to clip or be near clipping, i'd shoot with the intent of turning off HLX in post... which is counter intuitive...but not.

 

[Patrick Tresch]

Well what I call highlight recovery is what RED does by recovering clipped data with some sort of computing debayer magic.
I understand that there are various highlight recovery like the X track when shooting HDRX (with a number of Stops wich are shutter fraction of the base shutter) like on DSMC1+2
And there is also the Extende Highlights from the Raptor wich is, I assume, close to what HDRX is : second recorded track but with better integration (?)

 

[James Sielaff]

yeah, i'm just saying that Red's highlight recovery is not really recoverable in the traditional sense. so the naming convention is misleading.

HDRX and such are obviously different.

there are things you can do to make the grey blob work better, and hopefully A.I. will become a viable factor in that, but everything I can think of is labor intensive and hacky at best.

with Red's recovered data, it s best to just leave it up there in the highlights just before clipping and not try to bring back into lower values.

it also can look weird on people's faces when there are odd grey artifacts in high contrast lighting.

but you know all this, I'm just basically agreeing with you: yeah it looks bad and hopefully there is a havk for it that isn't super intense on hours and work required to fix it.

fortunately it is rare that anyone using lighting needs to fix it, but i have run into situations where i assumed i wasn't clipping because of the highlight recovery info being present on the monitor. it wasn't the worst thing, but not my favorite either. especially on Komodo, where DR is stretched a little more thinly than their other cameras. (yeah i know 12+ stops is plenty)

 

[Phil Holland]

Actual information.

RED has 3 major iterations of Color Science. Prior to IPP2, you managed clipped highlight color and tint via a feature called DRX. In IPP2, as you reach over exposure, it's now built in to taper off to desaturated white. When more than moderated over exposure occurs, it's possible to see more luminance detail than color. Ideally, like on any digital system, you don't over expose that much. Watch those RAW Meters and Exposure Tools.

The feature in IPP2 is called Highlight Extension, though wasn't broadly discussed outside of Graeme explaining the method long ago, and no DRX is involved anymore, which is a great thing. There's a host of other features of IPP2 that have improved via the demosaic, dimensional qualities, image noise, level of detail, color, etc. But you can investigate what previous versions of the color science offer in some 3rd party programs.

Now Extended Highlights, found specifically in V-Raptor [X] 8K VV as of this moment, is somewhat similar to the sudo-HDR approach of the previous HDRx. HDRx would record two streams back to back at half the max frame rates, and likely half the max data rates. The other track you could customize the exposure protection from 1-6 stops, then in post you would apply digital blend via SDK or manually to create your final image.

The newer iteration and method is now called Extended Highlights, which happens in camera and in post now. The global shutter of the sensor helps a lot in improving how this feature works. Additionally, there's a new method via temporal interpolation to make it all happen much better as well with moderate motion in frame. In my tests and measurements, Extended Highlights produces exactly 21 stops of Total Captured Dynamic Range. This is essentially a 6 stop over exposure protection with some of those stops allocated for the new digital blend area of overlap.

I showed some really impressive results on clipped sources with and without the "EH" on earlier in the year in my big old dynamic range test for RVRX. It works well when utilized correctly. If familiar with a stills workflow, you can moderately think of this as using a bracketed additional single exposure and blending to HDR.

 

[James Sielaff]

Thanks Phil, that is good to know. it may be Blackmagic Design that is responsible for getting us all to call it "highlight recovery".


blackmagic design highlight recovery

 

[James Sielaff]

I showed some really impressive results on clipped sources with and without the "EH" on earlier in the year in my big old dynamic range test for RVRX. It works well when utilized correctly. If familiar with a stills workflow, you can moderately think of this as using a bracketed additional single exposure and blending to HDR.

agreed, but we're just talking about the exception, and not the "correct" way.

i prefer having it vs not, and when it is filling in subtle details in the highlights, it is great usually. but it is not good for recovery, or whatever people seem to call it. it's good for what it is.

 

[Phil Holland]

Honestly, no digital camera looks good overexposed and clipping highlights Heck, some film stocks also aren't exactly wonderful in that regard either.