Motion blur the X-track in HDRx

[Dr. Sassi]

Nice set up, simple and clear.

I was just going through my own HDRX stuff searching for a fast movement there...(Instead of working on my shots). That clears it, again very nice, I love its simplicity.

OK, I'm convinced. )

Thanks for that, Les.

Hi Doc, here is a post I made on the subject in 2012, where I show clearly that the HDRX mode is two exposures.
You can reproduce by shooting a laser pointer doing circles on a surface.

http://www.reduser.net/forum/showthread.php?85324-HDR-0/page2

see my post #15 , has example images.

 

[Dr. Sassi]

Mark, you're right, I'm wrong in my interpretation of the manual. Sorry about the time it took.

 

[Christoffer Glans]

Haven't tried Mamba FX. When we were experimenting it occurred to me that someone could make a tool that did image analysis on both tracks then intelligently composited them. Ideally it would do the time realignment first and offer an "on time" X track for VFX work that was "centered" within the blurred A track. Obviously not all motion could be solved cleanly, but I would expect AI to handle most footage well enough to be unnoticeable. Based on Mark's notes, perhaps Mamba FX has this well enough sorted to make HDRx much less of a PITA - which would rock.

Cheers - #19

The best thing would be if Red could give this a little more love. I feel they almost "abandon" this after release. I believe they they can absolutely create something that is more smart than just a luma key mix as it is now.
I've mentioned to blackmagic about this for their Resolve, it can already handle HDRx, but even though the alignment in time is off by a fraction, post motion blur would definitely enhance the quality. Remember, most of the motion blur will blend together with the motion blur by the A-track, so it won't be as many artifacts as when doing it on a regular image at high shutter. But tests need to be done.

 

[Mark L. Pederson]

Haven't tried Mamba FX. When we were experimenting it occurred to me that someone could make a tool that did image analysis on both tracks then intelligently composited them. Ideally it would do the time realignment first and offer an "on time" X track for VFX work that was "centered" within the blurred A track. Obviously not all motion could be solved cleanly, but I would expect AI to handle most footage well enough to be unnoticeable. Based on Mark's notes, perhaps Mamba FX has this well enough sorted to make HDRx much less of a PITA - which would rock.

Cheers - #19

This is exactly what Mamba FX does.

EVAL is free and they just released MAC version. Mamba FX is very R3D friendly - since it's core code is Mistika and SGO and Peter Jackson and Park Road Post really pushed the development of the tools and support for R3D in the app for all the Hobbit films. It's one of the best kept secrets in VFX. Compare price and features to Nuke and you will understand.

Since I'm going on vacation for the next two weeks - maybe a Reduser or two (Gavin ???) can post a little HDRx in Mamba demo / turtorial

 

[Adam Johnson]

Thanks Mark, would LOVE for a little HDRx Mamba tutorial!!!

 

[Sam Sheppard]

Hi guys

I know the SGO guy who does the tutorials and he's literally just boarding a plane for a much deserved holiday. He said that he'll get a tutorial up when he gets back.

I've done quite a bit of work on HDRx (at least when it first came out, less so now) so I can say that the Mistika toolset (same as Mamba) gives you more options than most systems. Part of the reason is that the Mistika tools treat the 2 tracks more like stereo pairs for stereo 3D. Because of that it's very easy to add extra processes before the HDRx Merge in order to smooth out the transition - Optical Motion Blurs being an obvious one. HDRx can come with a lot of issues, particularly when combined with a rolling shutter. Motion Blur moving in the opposite direction to motion being a particular favourite that I save only my very best profanity for. For things like that I need Optical Flow tools to work 'between' frames.

To be fair though - 95% of the time I just throw away the HDRx and just debayer one track 'properly'. A Linear Light debayer will usually give you most of the exposure range that you're looking for without the motion artifacts. You can do that using tools like the ACES EXR export in REDCineX or the REDParams '16bit HDR' mode in Mamba. Note the difference between HDR and HDRx here though - HDR is extending the dynamic range using all of the information within the R3D file with no gamma, HDRx is using multiple exposures and blending between them.

Lots of ways to skin the cat. I choose shot to shot depending on what will get the best results. Apart from some very challenging material in India I mostly find that I don't need to use HDRx unless the DOP has had a REALLY bad day at the office.