Is there a camera that can do THIS?

S

szegedin

Member
Hey all. A friend just bought a Canon XA25, which can record two formats separately on two SD cards.
It got me thinking about something else: Is there any camera out yet that can record the same video but at two different levels of exposure, separately on two cards (or some variation thereof).
This is obviously one solution to a problem all photographers know; it would be very nice to be able to composite two levels in post. Not to go to an extreme of HDR, but just so you can shoot outdoors without blown out highlights. I'm expecting this feature any time now, but I don't keep up with camera technology. Appreciate if anyone can tip me off whether this is available yet.
 
I think the Varicam and Red cameras have this feature. It is only a matter of time before it trickles down as it is probably the cheaper way to get more dynamic range compared to making imaging chips with 15 stops. Cell phones are doing it automatically with stills, maybe with video too. But their chips are very small so it is easier to scan the sensor very quickly.
 
Bassman2003 said:
I think the Varicam and Red cameras have this feature.
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Cool thanks, good to know. Can't wait to someday see this on my Canon tXi. As I'm sure you know, you shoot "raw" video on these cameras with ml for example.... you can have 15 stops of "dynamic range," but it's still going to be all within the same ceiling and floor of highlights and shadows. Great colors, but your highs still blow out. Interesting that cell phones do it by merging two frames from 60fps or something, if that's what you're implying.
 
I don't know about cell phones and video but cell phones shoot HDR photos. Magic Lantern has its dual exposure approach which is two different ISOs which I think is the Varicam approach as well.
 
As long as you have HDR - and the lowest price camera with the Dual Readout HDR, as far as I know, is Red Raven at $7,000 for the brain only - you can get both the highlights and the shadows in most shots. Alexa and C300 MKII have this feature as well. I assume this is why cams like Red Weapon can claim 18 stops too (in reality, it's closer to 15-15 1/2 but that was the 35mm film's sole remaining advantage over digital and now it's gone as well).
 
DLD said:
the lowest price camera with the Dual Readout HDR, as far as I know, is Red Raven at $7,000 for the brain only - you can get both the highlights and the shadows in most shots. Alexa and C300 MKII have this feature as well.
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Thanks, great to know. At the rate things go, I should be able to afford to use something with that capability in three years or something.
 
Magic Lantern also does that, but AFAIK it's a double-exposure thing, similar to what RED does (or at least used to do, before Dragon): first it takes a "standard shutter speed" image, then, just afterwards, a "fast shutter speed" image. Usually they are almost identical except for exposure, but when there's motion one will show stuff that happened just slightly aftwerards, and will have much less motion blur.

If you're talking about reading out the analogue sensor data with two different amplification paths (dual gain ADCs), then most cameras with great DR do this, including the BlackMagic Pocket. But you don't get two different data streams: the camera puts both readouts together seamlessly before recording the data.
 
There's a Russian guy (Sergei Chornyi) who is developing a plug-in to get HDR out of a "regular" footage. This was his attempt at someone else's GH4.


A few years back, there was also an attempt to do HDR by combining two cameras with multiple exposures and then the compositing the image in post. It worked OK on landscape shots without much movement.

As I understand it, the dual readout - and ML 5DMKII hack does it in 1080p - only reads the luminance for the overlaid image, which saves on the bandwidth, processing power, data size, etc. Hypothetically, any camera capable of 48p, regardless of the resolution, should be capable of the dual exposure/dual readout at that given resolution. C300MKII does it without having 4K 60p - though 48p should do - which implies that the information present in that second readout is not as encompassing as in the first.
 
You can't make HDR out of footage that has already clipped highlights or shadows because the camera didn't have enough DR. You can shoot in a low contrast situation and make it look as if it was high contrast with HDR, using a filter, but that's useless if you ask me.

I want lots of DR because I shoot very often with people in the shade and a sunlit background. I'm usually a one-man-band with no time to light my scene, so that's all I can do if I want soft shadows.
This is the last video I have uploaded. The glass house in the background is in plain sunlight in summer in Spain, the girls are in a forest area, with four stops less light than the background. My RX100 IV shooting slog2 did very good here, but I wouldn't mind having a stop or two more than this.
 
That Russian guy calls it "tone mapping". He says he got 18 stops out of two joined Alexas and that his plug-in is close to completion/release.

I stumbled onto his VK page accidentally.
 
FWIW, 5D MKIV has a dual-exposure HDR mode but only in 1080p. It basically does alternate frames, then blends them together.
 
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