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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

HDRx motion interpolation

Jeff Coatney said:
But essentially we're frame interleaving here, right? There's no surplus bandwidth to write the frames at "the same time". And the X track exposure correction is a function of time between read-reset cycles. This would account for the unique motion blur that be achieved. Also the efficiency of making this part of a single R3D stream so the media can handle it. But in theory, the X track could be the "first" frame in the sequence giving the motion streak of the A track as a trailing, comet-tail effect, right?
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The interesting thing about HDRx is the the two tracks are conjoined. There is no time gap between the two frames. The sharp/blur are always connected.

Jim
 
Jeff Coatney said:
There's no surplus bandwidth to write the frames at "the same time". And the X track exposure correction is a function of time between read-reset cycles.
Click to expand...

I don't think that's right Jeff. I believe that there is the bandwidth to write both frames at once. That's why there are no motion artifacts and it's also why HDRx halves your available frame rates and it's why the Red One will never do HDRx - because the R1 doesn't have the surplus bandwidth but the Epic does.

The comet-tail effect is a result of two exposure lengths, one short and sharp, one longer and more blurred.
 
Shane Betts said:
I don't think that's right Jeff. I believe that there is the bandwidth to write both frames at once. That's why there are no motion artifacts and it's also why HDRx™ halves your available frame rates and it's why the Red One will never do HDRx™ - because the R1 doesn't have the surplus bandwidth but the Epic does.

The comet-tail effect is a result of two exposure lengths, one short and sharp, one longer and more blurred.
Click to expand...

Your theory being that the two exposures are happening simultaneously? As in: within the same read/reset cycle? The X track committing to the media at the beginning of this cycle and the A track following milliseconds later? Explain, please.
 
Jannard said:
The interesting thing about HDRx™ is the the two tracks are conjoined. There is no time gap between the two frames. The sharp/blur are always connected.

Jim
Click to expand...

Yes, this effect I noticed in some images in the barn shot. I will be shooting at-sea, in the waves, where the bright foam will be backlit against the dark trough of the wave. I'm interested in HDRx's ability to handle the motion of breaking surf. I will be happy with whatever I get in such a situation, just trying to predict what that will do from a motion perspective.
 
Jeff Coatney said:
Yes, this effect I noticed in some images in the barn shot. I will be shooting at-sea, in the waves, where the bright foam will be backlit against the dark trough of the wave. I'm interested in HDRx™™'s ability to handle the motion of breaking surf. I will be happy with whatever I get in such a situation, just trying to predict what that will do from a motion perspective.
Click to expand...

Please read my 1st post carefully...

Every motion camera ever made has "motion artifacts". Nothing reproduces exactly like we see. Some "artifacts" look better than others. Some we have gotten used to. "Magic Motion" and "MNMB" just create different types of motion artifacts... or motion "looks". There are limits to motion with every camera. HDRx™ and these two flavors of motion have their own different limits. Learn what they do and use them when they give you what you want. Turn them off when you don't get what you want.

Jim
 
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Jannard said:
Please read my 1st post carefully...

Every motion camera ever made has "motion artifacts". Nothing reproduces exactly like we see. Some "artifacts" look better than others. Some we have gotten used to. "Magic Motion" and "MNMB" just create different types of motion artifacts... or motion "looks". There are limits to motion with every camera. HDRx™™ and these two flavors of motion have their own different limits. Learn what they do and use them when they give you what you want. Turn them off when you don't get what you want.

Jim
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Trust me, I read all Your posts carefully :).
 
Assuming I am interpreting Jim's words correctly the "quick" X frame is read out during the time the longer base A frame is being read. Perhaps they start reading at the same time but the X "quick" frame finishes it's read sooner. Perhaps the X "quick" frame starts reading later then ends at the same time as the A frame. Perhaps it happens in the middle of the exposure time of the A frame.

Based on some characteristics of the Vegas sample footy the best current guess is that the X frame starts reading later in time than when the A frame starts reading but they both conclude their reads at the same time. In any case, it will be fun to watch this tech mature. While certain instances may "break" the illusion, I expect Graeme and the Foundry and others in the future to come up with very advanced ways to recombine the two frames to cover virtually any situation.

The more interesting aspect of this to me is something Jim has mentioned several times, what is the real world human visual experience of seeing fast moving things (or spinning your head quickly). When I wave my hand quickly what do I see? You can test this yourself without an EPIC assuming you have reasonably good normal (that's a thread in itself) vision. Obviously there is a whole debate about what we are conditioned to when watching movies or TV vs real world.

Here's to 48fps base frame rate, HDR, 4K measured resolution after decode imagery and the future - Cheers!

- #19
 
Jannard said:
Please read my 1st post carefully...

Every motion camera ever made has "motion artifacts". Nothing reproduces exactly like we see. Some "artifacts" look better than others. Some we have gotten used to. "Magic Motion" and "MNMB" just create different types of motion artifacts... or motion "looks". There are limits to motion with every camera. HDRx™™ and these two flavors of motion have their own different limits. Learn what they do and use them when they give you what you want. Turn them off when you don't get what you want.

Jim
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Hey Jim wouldn't it be awesome if the camera could have have a peripheral view instead of everything being tunnel vision or box vision .. i guess screens would have to be somewhat concave.. i love the whole HDRx idea

i called it .. i knew secret #21 was hdr look it up the post is still there muahaha evil genius strikes again

but i digress
 
Blair S. Paulsen said:
Based on some characteristics of the Vegas sample footy the best current guess is that the X frame starts reading later in time than when the A frame starts reading but they both conclude their reads at the same time.
- #19
Click to expand...

This is what I observed as well. Since shots are usually edited into a larger context, and the head and tails of them are cast aside, perhaps by shifting the X frame upstream or downstream in time a frame, one can affect the appearance of any motion artifacts within shots? Perhaps if this is currently elusive, at some point in the future, this may be possible? Seems simple enough in theory-- although I am very satisfied with the current capabilities of HDRx as she stands now. A huge Bravo! And I can't wait to play with it.
 
Blair S. Paulsen said:
Assuming I am interpreting Jim's words correctly the "quick" X frame is read out during the time the longer base A frame is being read. Perhaps they start reading at the same time but the X "quick" frame finishes it's read sooner. Perhaps the X "quick" frame starts reading later then ends at the same time as the A frame. Perhaps it happens in the middle of the exposure time of the A frame.

Based on some characteristics of the Vegas sample footy the best current guess is that the X frame starts reading later in time than when the A frame starts reading but they both conclude their reads at the same time...
Click to expand...

I'm thinking this too, except that they must start at the same time, with the X frame finishing earlier - hence the A frame motion blur trail following after the sharp X frame. This would make sense as once a pixel is overexposed, you can't retrieve highlight information.

IF this is right (wildly speculating), then it is unfortunately not going to allow us to make HDR stills of the same frame in time with "second curtain" characteristics like DSLRs. Not a big deal with motion footage, but perhaps slightly odd looking in a still.

I suppose it would be possible to move the X frame sampling window later, but as it got later, it would have less and less ability to retrieve highlight detail, BUT if the frame wasn't overexposed anyway
(or we didn't care about a few clipped spots), it might allow a "second curtain" like blur-sharp still look? Hmm.
 
David Quinn Carder said:
At a sufficient frame rate these artifacts would be virtually non-existent, correct? I know most people seem to be interested in sticking with the legacy 24fps format…
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The higher the initial shutter speed, the less motion blur there is with both images and the less disparity between the two. This also means less "Magic Motion".

My bet is that this year will be the discovery of how to use this new tool.

Jim
 
ericyoung said:
I'm thinking this too, except that they must start at the same time, with the X frame finishing earlier
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This is not accurate.

Jim
 
Jannard said:
Ruairi... with all due respect, you have gotten used to an illusion. 24fps at 180 degree shutter is not how we see. Have someone swing their arm over their head from one side to the other. If this was shot 24fps at 1/48th shutter all you would see is a big motion blur until the arm stopped. But that isn't what your eyes see. They see a combination of motion blur and sharper references to the arm all along the way.

Jim
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My eyes don't work that way unless my eyes track the arm. My eyes seem to work exactly like a normal shutter.

But if I follow the arm it's motion blur free and the BG is motion blurred. If I follow a filmed arm on a screen, it's obviously still motion blurred. So in *that* respect I suppose they are similar. But I don't just normally see in magic motion.
 
Gavin Greenwalt said:
My eyes don't work that way unless my eyes track the arm. My eyes seem to work exactly like a normal shutter.

But if I follow the arm it's motion blur free and the BG is motion blurred. If I follow a filmed arm on a screen, it's obviously still motion blurred. So in *that* respect I suppose they are similar. But I don't just normally see in magic motion.
Click to expand...

www.oakley.com/store/prescription

Jim
 
Jannard said:
My bet is that this year will be the discovery of how to use this new tool.
Click to expand...

My first feature would not be possible without Epic/Scarlet for many reasons… I can't wait to blow people away with the as-of-yet untapped potential y'all are providing. I hope one day I can show my appreciation adequately but for now I'm just thankful! The timing couldn't be better for me.

Jannard said:
www.oakley.com/store/prescription
Click to expand...

Nearly sprayed my laptop with tea! :D
 
will i be abel to use Epic-S HDRx at 25fps
 
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