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EXPERIMENT: Use 3-D Rig For HDR?

Joe G.

Joe G.

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Hi there. If anyone has a 3-D rig with a beam splitter, we have been pondering the options for HDR photography (in a different thread), and this one sounds like a possibility right now.

Instead of using the two cameras for stereo side by side, use lots of ND on one of them, and try different exposures in order to get a very high and very low light version of the same image.

I don't know if there is an easy software solution to blend the two in the best possible way without a lot of post work, but it should be doable.

Anyone care to give it a try??????
 
I have asked for this before. It would be very cool to see it happen. However you would lose some sensitivity, and obviously mobility. The new DSMC's will have more DR but it would be very cool to see this happen with them since they will be more sensitive and much much smaller. I know there is a limit to what you can get out of a super extended DR while keeping the result realistic, but it would be so sweet to manipulate skies (or snow, sand, or any highlights)... no need to replace them unless they look boring... though you might still need to do a lot of rotoscoping for full control over the sky itself.
 
But how would you optically converge the images? In order for HDR to work you have to have almost identical perspectives, otherwise it will blur anywhere the two images converge- which is of course the point of a 3D rig.

-Noah
 
@noah not necessarily blurry, you can converge the HDRs by aligning the edges after a 'find edges' pass. Then just cut into the image a little and roto your f-stops. Autodesk Toxic has a direct control for that but you can do the same in Nuke or Shake as well with simple rotoshapes and some tracking.
 
Also, doing this at 4k for 1080p, or 5k, 6k! You have so much detail that keeping sharpness high would be a piece of cake at 2k. Also, if you are splitting the beam it is a matter of making sure your optical paths are properly designed, calibrated, whatever... I don't know enough about optics, but all that is designed properly, and possible, then it shouldn't be an issue.

I wonder what would be the sensitivity of the "shadows camera" with half the light? That would dictate the exposure you would need to light for in order to avoid too much noise in that camera. Or you could just use the sensitivity of the "highlight camera" when you only need to get a normal look. Or just shoot with a single camera for night stuff which I suppose is perceived by the human eye to be lower in DR anyway. Right?

DSMC should be perfectly suited for this sort of application. With the right optical design for the splitter mumbo jumbo you might even end up with something equal in size to an F35! (?!)

I guess if your ratios aren't there you can't make it better with post, but you would always get all the info and you wouldn't have to fight to sandwich the light so much so you might save time.
 
HDR Test

HDR Test

we have used a 3D rig to do this very test. Taking the interaxial distance to zero and aligning both cameras through a mirror rig we shot exactly the same shot but at different exposures. We crystal locked two A Minima S16 cameras and shot Vision 2 7217 with a three stop offset.

The spec TVC is still going through editorial but hopefully soon we will process the images but at first glance the dynamic range of the film stock is awesome and it remains to be seen but the overexposed camera may have captured the full dynamic range presented to it on our sunny day. I will report back our results when they are complete.

Tom Gleeson
DOP Sydney
 
Tom Gleeson said:
we have used a 3D rig to do this very test. Taking the interaxial distance to zero and aligning both cameras through a mirror rig we shot exactly the same shot but at different exposures. We crystal locked two A Minima S16 cameras and shot Vision 2 7217 with a three stop offset.

The spec TVC is still going through editorial but hopefully soon we will process the images but at first glance the dynamic range of the film stock is awesome and it remains to be seen but the overexposed camera may have captured the full dynamic range presented to it on our sunny day. I will report back our results when they are complete.

Tom Gleeson
DOP Sydney
Click to expand...

I am sure this will be something everyone (especially Kodak) will be very interested in seeing the results from. If it offers one more tool in the arsenal that can't yet be achieved by digital imagers (not just increased DR, but HDR photography) then it will hopefully show that film has a few more tricks up it's sleeve.

Note: I'm a huge proponent of digital, but I also really LOVE it when people use a tool to new and interesting effect, due to evolution of not only complimentary technology - stereoscopic rigs in this instance - but also competing technology - digital still cameras undoubtedly increased the popularity of HDR photography - now motion film cameras may get the opportunity to take that interest and reinvent it themselves to create an entirely new look. That's real progress in action!
 
How is HDR limited to film? If anything you could go as far as automating the HDR merge in digital with a box and record the HDR files directly. You'd be able to grade on set, which you couldn't with film.

If you mean that one film camera could achieve the same as two digitals then I would assume that two 14-bit DSMCs would more than clear the DR of any one stock. And everyone knows about film's DR being greater than any digital to date.
 
HDR isn't limited to film, however at THIS particular juncture it's a better medium for this experiment.

In the future that may well change - but that was my point about progress. Progress is not only looking at new technology, but looking at new practices and thinking about how we can reuse older technologies to create new art and vision.
 
Ok, but I still don't understand what data would be gathered from testing film HDR that is more relevant when it costs so much more and takes so much more time.

Do you mean because most big budget stuff is still being shot on film? So for now it would still be more relevant to see the results with film? I know the benefits of shooting film over digital, I just don't see why it would be a better medium for something like this when the nature of HDR is in fact something that would make digital match film in terms of DR. I see it as much more relevant to see if two digital cameras could "catch up" with one film camera in this sense.

If I found it a possibility to shoot with a pair of DSMC brains with an optical mumbo-jumbo in front of them that only ended up making the whole apparatus about the size of a film camera, with no magazines!, then I would be thrilled about that. While shooting with two Arri 235's would no doubt give you a bigger and heavier rig. Also, you'd be burning twice as much film where recording twice as much digital data is a walk in the park in comparison to the cost of the stock and processing.

Plus, the sole possibility of merging both digital streams with a "box" if someone made one and have this box on the rig itself would mean that your DP and director would be able to work in a whole new way. I am no DP, and shooting with a nasty video tap is not what I want to be creating with when I can not extrapolate settings and stocks into the final look in my mind, especially not if there is the option to create seeing the real deal, and more so if it is actually more affordable to do it with digital and get something even better than the second generation of a camera line that already looks so amazing.
 
Most high-end DPs know how to light and filter scenes to fit their stock or electronic latitude as shot not try to rely on HDR to save shots with too much contrast. I'm a much bigger fan of NDs, Polarizers, big lights, flags and silks than carrying around two fully massive camera bodies and knowing every shot will have to be electronically re-aligned just to gain a few stops...

Noah
 
I love HDR imaging and getting more and more done, just never have in off time to do the edits once I return, hehe.

In fact Digital has so much more power in HDR then film ever had, and Digital continues to move forward with new designs and technologies allowing ever more for fantastic HDR imaging, currently I use the 1Ds III, even so for the purpose of HDR a faster shutter camera like the 10fps 1D III will be better, and you can shoot up to 7 consecutive frames at increments up to 3 stops.

With Red you can definitely do HDR, both in a Beam splitter "L" configuration set up or an S3D set up on a parallel axis, but you only get two exposures at the time, so why not just shoot with one camera and expose differently per every shot, since what you doing is using the MOtion camera to extract stills doesn't make sense to use a complicated 3D rig for such a purpose, at list not that I can see.

ciao
 
Of course a DP can manipulate the contrast of a scene, otherwise they wouldn't be a DP. What I am talking about is being able to give that DP something that lets them create without having to fight the light so much. Also, make it so that you can save time and money since you don't have to pull every light from the truck.

Ketch, I wasn't talking about stills. And like i said earlier, I am more exited about doing this with the future smaller cameras.
 
Roberto Lequeux said:
Ketch, I wasn't talking about stills. And like i said earlier, I am more exited about doing this with the future smaller cameras.
Click to expand...

Understood Roberto, and yes I'm as exited as you are, or possibly more, about doing some serious S3D with the smaller bodies of Scarlet and Epic, even if Epic be a bit larger then Scarlet, the design will make Perfect for S3D configurations.

ciao
 
Must be nice. Have fun. I am not into 3d (is that what S3D is?) but using the same thing for HDR might be loads of fun... perhaps something a bit more conducive for a specific effect however.

For example, I have a large portion of a project where I would love to get crazy skies for... I could replace them and spend budget into actual sky replacement, or we could hope for enough day with decent skies and do something like this. Or close, since he probably shot several pictures... still, two gives you most of the bang.


By Scott Kelby

Of course, then you are at the mercy of mother nature when it comes to the clouds. And while two Epics would be small they may not be as small as you'd wish unless someone designed the smallest possible beam splitter for them since I assume all out right now are behemoths. Or are they? Can one be designed so that they are side by side? Or just closer together?

How small do you think they could get Ketch? You should know.
 
Great shot Roberto, you did a fantastic work on the final HDR Tone mapping, I do not very much like the over toned mapping of some HDR's were they seems more surreal cartoonish drawings, I much prefer instead Photo realism, with over sutured Vivid colors in it, with the Tone Mapping done were the vision of a real world is presented by its life characteristics in color and depth.


S3D stands for "Stereoscopic 3D" just so to make a differentiation from 3D, generally understood as 3D Animatin, vs. S3D filming real actors in 3D. I don't like very much when it is achieved by the use of a Beam Splitter configured in an "L" shape which requires for a very large and almost impossible configuration to use in any Shoulder or hand held configuration, instead I prefer when done by configuring the two cameras in a Parallel axis configuration (Side by Side) this type of rig can get as small as the cameras them self, think it of as if it was a Dovetail side ways were the cameras are mounted on side by side and they can be moved closer or apart from each other, and a secondary Axis to allow the cameras to be positioned in a V shape with the lenses pointing in words, this off course must be achievable by smooth movement of the rotation of the axis preferably done by a Will, just like in the ARRI Head.

This is what I prefer as it gives a far more realistic and a much better 3D depth to the images in a very realistic way, dramatizing so much more your characters and your story, no objects flying out on you form the screen kind of thing.

So this type of configuration is extremely light, very versatile as far as mounting options and easy to transport, so Scarlet, and Epic will definitely be a game changer in this type of Rig, right now the best rig in use is that of Pace, Fusion 3D, but it is HUGE!! So Huge in fact that the Brain and lenses are the one mounted on the Parallel Axis while the Rolls are mounted further away from the Rig, so to allow for faster movement and ease of control.

The Stereoscopic 3D rigs such as the one from ET (limited to rental for now) or the one form P+S Technic, will get so much smaller with Scarlet and Epic.

ciao
 
KETCH ROSSI said:
Great shot Roberto, you did a fantastic work on the final HDR Tone mapping, I do not very much like the over toned mapping of some HDR's were they seems more surreal cartoonish drawings, I much prefer instead Photo realism, with over sutured Vivid colors in it, with the Tone Mapping done were the vision of a real world is presented by its life characteristics in color and depth.
Click to expand...

Oh, crap... Click on the photograph please. I am so sorry. I apologize to Scott Kelby for being lazy and only making his photo a link to his website, where I copied it from because I thought it was such a great example for the point I was trying to make. I should have also put his name below it.

I agree though, once you lose realism you lose the ability to affect people in that certain serious way. Of course cartoons can also be stunning works of art.

I hope someone hurries up and makes a beam splitter for Epic. I would suppose companies like P+S Technic will jump on it, fully appreciating the impact, as you do.

Is there a benefit to shooting 3D with a beam splitter as opposed to using cameras side by side? Is it so that you can get narrower distances from eye to eye?
 
Roberto Lequeux said:
Oh, crap... Click on the photograph please. I am so sorry. I apologize to Scott Kelby for being lazy and only making his photo a link to his website, where I copied it from because I thought it was such a great example for the point I was trying to make. I should have also put his name below it.

I agree though, once you lose realism you lose the ability to affect people in that certain serious way. Of course cartoons can also be stunning works of art.

I hope someone hurries up and makes a beam splitter for Epic. I would suppose companies like P+S Technic will jump on it, fully appreciating the impact, as you do.

Is there a benefit to shooting 3D with a beam splitter as opposed to using cameras side by side? Is it so that you can get narrower distances from eye to eye?
Click to expand...


Haha! Got it, I tough you tucked and create the post workflow on it.

Most of the current 3D rigs using a Beam Splitter such as the ET rig and the P+S T rig, I imagine would have no issues at all to be sued for the Scar;et and or Epic, but I still would use such a configuration for a very limited amount of shots were you could not achieve them using a Parallel Stereoscopic rig.

To me it just is a better way of transferring the Emotion, Drama, and true nature of how humans perceive motion in real world, just accentuated by the use of artistic digital manipulation and specific Plane of Focus to direct the viewers attention to what matters most in the story, and this is why Cameron chose the Parallel Stereo System vs. the Beam Splitter for AVATAR, even if some scenes were still captured with the implementation of a Beam Splitter rig.

To me the most important thing in a Stereo 3D rig remains the capacity to implement as much as possible the technology and make use of it to replicate as close as possible the natural eye movement and interpretation of how we Humans thru our eyes capture and process images, especially motion, as if not done right will never look right, no matter how much post you do, and crappy 3D is not bad, it will make you sick till you vomit, and if you have a strong stomach and you watch just the same, will put such a strain in your eyes that they could even get damaged.

The narrow distance that you look for to achieve in a Parallel Stereo rig is generally is set @ 2.5" (64mm) measuring from the center of each front lens element, from here they can be moved closer to each other or further apart to create e desired effect of Shrinking or enlarging the photographed subjects out of their original proportions, for any reasons of artistic reason in the Storytelling.

But what is more important is the capacity of Converging the point of view of the lenses when configured in such a Parallel Stereo rig, allowing for changing the Plane of Focus as needed to guide the viewers attention were the Director wishes to, as we normally do in 2D Photography while we use DOF to direct the viewers attention were we like.
 
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