HDRx footage...

[Gunleik Groven]

Really don't want to get involved in this again, but there is a huge difference between two exposures (say 1/50th and 1/200th of a sec at the same F-stop) and two different metadatasettings (say 200 and 800 iso on RED RAW).

The first example extends the DR by two stops, the second - on MX you don't even change the noise charracteristics and levels, you just change the visibility of it.

In other words: You basically change nothing but levels. And it has nothing to do with even easy HDR.

(On the M OTOH, there are good arguments to lower the ISO and pick up the image with a curve to avoid noise.
On the MX you don't even get that extra bonus by doing "ISO messing")

Ouch.

Back into my rabbithole again....

 

[Uli Plank]

I second this. You can feed a single raw image with high latitude into Photomatix and have it tonemapped (16 bit TIFF or the like). The sky will look just as awful as in the helicopter shot… (Well, I think I could tweak it a bit better)

Plus, as soon as anything moves, you get fluctuations of the halos!

 

[Sanjin Jukic]

I'm just curious how many funny comments about Easy HDR and HDRx will get RED team from all those "HDR experts" here when Epic/Scarlet start to ship.

 

[Joseph Hutson]

I'm just curious how many funny comments about Easy HDR and HDRx™™ will get RED team from all those "HDR experts" here when Epic/Scarlet start to ship.

"Go easy on the HDR!". That's what she said. :biggrinjester:


Okay, you were probably talking about other funny things...

 

[Floris Liesker]

I've set up an After Effects project which reduces/eliminates the motion artifacts found in the HDRx footage. You can view it here on vimeo.

It's done quite roughly (from the H.264 Jim put online) but it's good enough for giving an impression of what MNMB could look like. I basically split the image into a shadow and a highlight part, (at RGB 160,150,140) and added motion blur to the highlights using the CC time warp. I fiddled with the timing and the gammas and added the two together again.

The effect is most visible paused at 09:00 / 22:00 when a LED hand sign sweeps through the frame. Also watch the lights above the entry of the building left of the hand sign. In the original film you can quite clearly see a greyish clipping of the long exposure and a fast-shutter version behind it. In the motion blur version it looks more like a normal exposure. I think this effect will work just as well with a 6+ setting (I think this is shot at +3) giving you a highlight headroom of 6 stops on top of the 12+ stops you already have!

Funnily enough: when in motion it's very hard to even distinguish the two versions! I don't know why that is, must be something with the way the eye/brain sees movement.

I guess I could live with HDRx without any render-heavy MNMB added, at least by the looks of the moving footage. The stills do look a lot better with it though...

 

[Gavin Greenwalt]

Cool experiment.

 

[Athiril]

The jury is still out on Scarlet and HDR but it just does not have the processing power of an EPIC.

I have to wonder if Scarlet owners would prefer HDR in their cameras if they had to pay extra for it. We could up the processing power by adding boards but that will cost money and I'm not sure if Scarlet buyers will go for it. Some feedback on this would be helpful on another thread in the Scarlet section of reduser. Given the change in development path, board costs, an additional ASIC and "stuff", we are probably looking at an additional $1000 more or less.

If we did this, Scarlet could have both EasyHDR™ at 30fps and HDRx™ to 60fps.

Just thinking out loud here...

Someone want to start a thread there? It should be good for a lively debate.

Jim

Not possible to make that modular is it, like an expansion?

Very cool effect. Thinking out loud here: As someone has already commented, it's like a first-curtain strobe sync, both in look and presumably in principle. It seems clear from this that the sensor is being read twice during the exposure. Not two separate exposures, but once a fraction of the way into it, before the highlight clipping and motion blur occur, and then once again at the end of the full exposure.

The really fascinating part is that with this method, the initial blurless lights would be darker and the motion blur streaks would be brighter or even blown out. Apparently Graeme's magic pixies take the non-clipped information from the first fraction of the exposure, before the "light bucket" overflows, then use that to fill in the blown-out streaks, after dimming it down to make the blur look right. All of which sounds to me like a ridiculous amount of real-time processing.

Very impressive! Here's hoping it can be crammed into Scarlet. If not, I'll just have to make sure I earn enough with Scarlet to upgrade soon!

Not sure why no one has tried a compressor/limiter before the ADC.

 

[David Rasberry]

Not possible to make that modular is it, like an expansion?

You are behind the curve. Scarlet, as well as all other new Red models have already been upgraded to include HDRx. The extra boards and processing have been added to support it.




Not sure why no one has tried a compressor/limiter before the ADC.

Most video cameras now on the market use compression in one form or another to mitigate highlight clipping within the available 9-10 stop dynamic range.
HDRx is nothing like that. It is a true dual exposure mode like one would use to do HDR with a still camera. One exposure for the shadows, and one for the highlights which are then combined. So you get a full exposure range without clipping of up to 18 stops.
The unique aspect of HDRx is that both exposures are recorded within the same frame.