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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 :)

Rolling shutter test with #232

Floris Liesker said:
He's not talking about flashes he missed but flashes that only appear above or below a very hard line. There is no easy post workaround for that.
I still think setting the camera to 360 shutter and using some aftermarket shutter in or in front of the lens should do the trick.
Click to expand...

If we have to be so specific about what he is talking then he is wrong to worry about it as "ambulance, firetruck, and a few police cars at night" never have so rapid flashes to cause a problem.

I am 100% sure that the scene he is talking about will have zero issues.

As far as the film camera behaviour goes, i have captured 2 times a flash that was only visible on half of the frame while shooting a short film. The only difference was that the edge was softer.
 
Floris Liesker said:
He's not talking about flashes he missed but flashes that only appear above or below a very hard line. There is no easy post workaround for that.
I still think setting the camera to 360 shutter and using some aftermarket shutter in or in front of the lens should do the trick.
Click to expand...

Right but the question is does such a product exist.
An LCD Shutter will not work.

IBloom
 
Miltos Pilalitos said:
If we have to be so specific about what he is talking then he is wrong to worry about it as "ambulance, firetruck, and a few police cars at night" never have so rapid flashes to cause a problem.

I am 100% sure that the scene he is talking about will have zero issues.

As far as the film camera behaviour goes, i have captured 2 times a flash that was only visible on half of the frame while shooting a short film. The only difference was that the edge was softer.
Click to expand...

There's a clip from an EX1 floating around that shows all kinds of problems with a police car and modern cop car lights... no more old school light bulbs in their rack I guess.

Film does have the same issue, but the out of focus shutter makes for a soft edge... here's some from the movie Pitch Black...

PitchBlack_strobes.jpg
 
It's the shutter line that's the problem with strobes. . .

It's the shutter line that's the problem with strobes. . .

Yes. . . let me make myself clearer. I am not concerned EVER about missing flashes from gunshots. . . those will surely be an easy fix in post. What I AM concerned about is strips of fully-lighted and half-lighted frames. It's gonna be a mess with the RED under these circumstances. Heck. . . someone with a RED (mine isn't here yet). . . find a cop car (tell 'em that someone stole your RED, that ought to get 'em there quickly . . . :-) and catch some footage of the car with the lights illuminating the buildings and people next to the car. I think it's going to be a huge issue for everyone eventually. Film frames have a very different look for several reasons, one of which, as noted above, is the fact that, being so close, the shutter is so out-of-focus that it we don't see the blades all that clearly. It's NOTHING like the problem that the RED has. There is simply no way to synch all of these strobing lights (at least not on an indie set like mine!), and wouldn't that look strange if they did. . .

Unfortunately, I doubt if there is a workaround for this issue, other than some external shutter device. THAT would solve the problem, but, again, who know how much something like that would cost and what other problems it might bring to the table.

Stephen
 
I doubt that police beacons (if that is what is being mentioned above) would create the problem as they (i would think) flash for considerably longer than the sub frame duration that causes this artifact.

after that all that would be required is a sync unit to lock strobes to the camera shutter (I couldn't imagine that this would be a hugely difficult engineering task). Put it this way - whoever comes up with this product will certainly sell a lot of units.

In the short term it looks like the old brute shutters (like we used to use years ago) might come back into fashion for music videos shot with Red.
 
I am certain that modern police strobes flash for FAR less than 1/48th of a second. There is going to be an issue. It just remains to be seen how much of an issue it is going to turn out to be. The skew issue isn't a big deal to me (I mean, of course, we'd prefer for it not to be there), but there is NO WAY one can synch three or four emergency vehicles. The cops wouldn't let us tinker with vehicles for all the tea in China!

Stephen
 
Great test!!! It appears that the strobe and skew are the same problem. Film cameras capture, despite the shutter angle, a "real" frame, and whatever light is in that frame, that’s what you get, so you can get the exact time of the flash, getting 100% of the light, or just before of after the exact time of the flash, getting less light. Here with the RED camera (strobe and skew problems), it looks like the frame is a composition of 2 frames, more like an interlaced frame. On film the shutter is an angle and not a time (of course the angle will dictate the amount of time of the exposure). Here it looks that the shutter is making 2 passes ate THE SAME frame, getting 2 different levels of exposure (tht strobe problem), or 2 different angles in a straight line (the skew problem). I'm sure it's something will be eventually be fixed and the 10% will already be and advance, but of course the goal is to match the film level of no skew and flash problems.
 
Yes, the EX1 is the same. Again, after looking at Jim's results, it sure looks a lot like the EX1 CMOS rolling shutter artifacts. I still really enjoy the image coming off my EX1. It's quite the breakthrough in the sub $7k market.

Partial exposures caused by stobe lights will have to be fixed in post. As far as skew, I guess we'll have to be careful. I imagine most skew will be covered up from 24P 180 degree shutter motion blur.
 
Jannard said:
These tests seem to accurately show the amount of skew on the RED ONE (as it is now). There will be about a 10% improvement in Build 13 or 14 with a settings change.

Jim
Click to expand...

Thanks Jim. Is there any hope for more improvement or is that limited by the sensor now? Which I assumed it was in the first place.
 
i've tried to find a post solution to fixing the strobe issue, but have not been able to. has anyone seen one?
 
I've had issues with police lights as well, i'll post some stills shortly - camera was set to 1/48 shutter 24fps
 
That's it! Thanks REDRUM. . . I had seen that footage, but forgot about it. That's exactly the issue I'm tallking about. There are a whole lot of films what will have police/ambulance/firetrucks/etc. in them. And I'm now relatively convinced that we won't be able to use the RED for those shots. And that's a real bummer. I'm going to have to change the scene I was going to shoot completely to get rid of the emergency vehicles.

This is, to my mind, the #1 issue to be resolved with the RED. Unfortunately, it may not be resolveable.

:-(

Stephen
 
the ex1 footage looks horrible, but i could buy it in a science fiction movie,
red test for with police, firetrucks, ambulance and especially guuuuun shots would be good to see.
 
Yes, it does look horrible. I think we're toast on cop cars. And unless guns are electronically synched to fire only with the sensor wide open, we are going to be very disappointed with gunshots, as well. Anything that throws a quick burst of light in darkness is going to be ruined if it isn't synched. Oh, for a global shutter. . .

:-(

Stephen
 
Red basically will perform similar to what you are seeing in the EX-1 on strobing in my experience with the camera. This is hands down the most limiting feature of the camera IMO. I think this is the one issue which is potentially a show stopper for me too...
 
The current RED sensor will continue to refine and improve, but yes, both the EX1 and the RED will perform in a very similar way with skew and strobe issues. Both have their places I think...

The RED gives you a cine experience in terms of handling the camera, along with 35mm lens choices and the DOF you'd expect. I've spent some time grading our clips with REDCINE and it's the same heady experience of sitting in a telecine bay with film on the reels. The final image is smooth and rich. It's cinema.

The EX1 will likely be my second camera since I just sold my HVX. Hell, first, until RED ships. It's tack sharp, most likely better than RED in resolution when RED is 2K windowed, and you can be a one-man band with it.

This whole CMOS thing is what it is at the moment. Maybe the next generation RED sensor will be a 6K 3200K native balanced global shutter design... then this whole period of rolling shutter will be over and done...
 
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