FS7: Viewfinder Judder at 60P (4K or 2K)

basspig

basspig

Veteran
Today, I was testing 8.1 OS firmware upgrade on my Shogun Inferno, and discovered that it now supports 4K DCI at 60P. So I did some tests, one of which involved panning the camera. I noticed a very prominent judder effect as I panned. Much worse than at 24P. This effect was just as pronounced in both the FS7 VF as well as the Shogun Inferno's screen.

The recorded signal has no dropped frames and plays smoothly.

Is this some sort of motion aliasing issue? Is it LCD lag? Or are the displays actually dropping frames?
 
About 10° per second. Not fast at all. The thing is, the panning looks smoother at 24P than at 60P on the viewfinder and on the Shogun display. The recorded file looks smooth at 60P when played on the NLE. So it's not being recorded with dropped frames. It seems to be an issue with the LCDs in both the camera and the Shogun.
 
In which case I assume you're hitting the max refresh rate of the monitor and the panning is showing it more
 
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Does the camera LCD judder when the Inferno is unplugged? I tested the camera at various settings DCI 60p settings, both Cine EI and Custom and can't see anything unusual. The pans look very smooth as expected. Are you sure you are talking about 60p (59.94) and not 60fps slow motion setting at 23.98 which does have judder in pans (when viewed on LCD while shooting)?
 
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I'm talking about normal, 59.94P frame rates.

And as an experiment, I unplugged the Shogun from the camera and watched the viewfinder image as I panned back and forth. It's definitely a LOT smoother at 23.98P than at 59.94P when panning.

Possibly the higher frame rate is aliasing against the refresh rate of the LCD?
 
basspig said:
I'm talking about normal, 59.94P frame rates.

And as an experiment, I unplugged the Shogun from the camera and watched the viewfinder image as I panned back and forth. It's definitely a LOT smoother at 23.98P than at 59.94P when panning.

Possibly the higher frame rate is aliasing against the refresh rate of the LCD?
Click to expand...

You are toggling between 23.98p and 59.94p under SYSTEM > REC FORMAT > VIDEO FORMAT , correct?
 
basspig said:
Possibly the higher frame rate is aliasing against the refresh rate of the LCD?
Click to expand...

I doubt that LCD's refresh rate is less than 60Hz which should display 60p without judder as it does on my camera (at 60p pans are liquid-like smooth in DCI 4K and other resolutions, as expected). Unless there is something in your settings that is causing it, considering all other issues you've been having with your camera that no one could replicate, I begin to think that you have a faulty unit.
 
ProfessorU said:
Are you comparing the same shutter speeds?
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I don't think it matters at 60p that much. I mean, of course it does if you compare 60p 1/60th vs 60p 1/250th but in a context of this thread it does not, in that pans at 60p look much smoother compared to 24p no matter the shutter speed. Basspig claims that 24p looks much smoother and 60p has pronounced judder.
 
broughtonfilm said:
I don't think it matters at 60p that much. I mean, of course it does if you compare 60p 1/60th vs 60p 1/250th but in a context of this thread it does not, in that pans at 60p look much smoother compared to 24p no matter the shutter speed. Basspig claims that 24p looks much smoother and 60p has pronounced judder.
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BINGO! The FS7 has a quirk, where it sets the shutter to 1/15th second when the camera is in 60P frame rate. I manually adjusted the shutter to 1/60th and it is smooth on the pans now.

Which begs the question, why doesn't the FS7 adjust the shutter to match the frame rate? It goes in the opposite direction, dropping from 1/48th in 24P, to 1/15th in 60P--makes no sense!
 
basspig said:
BINGO! The FS7 has a quirk, where it sets the shutter to 1/15th second when the camera is in 60P frame rate. I manually adjusted the shutter to 1/60th and it is smooth on the pans now.

Which begs the question, why doesn't the FS7 adjust the shutter to match the frame rate? It goes in the opposite direction, dropping from 1/48th in 24P, to 1/15th in 60P--makes no sense!
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Mine does not do it. What is your firmware version? And if your camera changes the shutter speed to 1/15th, how do you explain that it had judder on EVF / LCD but not in NLE? Slowest "normal" speed in 60p is 1/60th, everything below that has to double the frames, in case of 1/15th quadruple them.
 
Other than the shutter angle bug on early firmware I have never encountered issues where the camera changed my shutter speed out of 180deg unless I changed it manually.
 
FrameFarmMedia said:
Other than the shutter angle bug on early firmware I have never encountered issues where the camera changed my shutter speed out of 180deg unless I changed it manually.
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Is it possible to have a shutter speed lower than the frame rate outside of slow shutter mode..? directed to the OP not the quote sorry..
 
I use shutter speed instead of angle, so maybe that's the difference. I'm on firmware 4.x on both FS7s. Both have this anomaly, where the shutter speed (not angle) slows down when camera frame rate is set to 60P.

What I noticed is that the brightness levels do not change when in this mode. That is a clue that the shutter speed did not track the frame rate change. Normally, the camera should lose a lot of light going to 60P.

It probably doesn't have this behavior in shutter angle mode. But a simple firmware revision should be able to fix the shutter speed mode as well, so they track the frame rate better.
 
basspig said:
I use shutter speed instead of angle, so maybe that's the difference. I'm on firmware 4.x on both FS7s. Both have this anomaly, where the shutter speed (not angle) slows down when camera frame rate is set to 60P.

What I noticed is that the brightness levels do not change when in this mode. That is a clue that the shutter speed did not track the frame rate change. Normally, the camera should lose a lot of light going to 60P.

It probably doesn't have this behavior in shutter angle mode. But a simple firmware revision should be able to fix the shutter speed mode as well, so they track the frame rate better.
Click to expand...

Once again, you claimed that the pans in the footage played smoothly without judder in your NLE which made me (and probably everyone else replying here) assume you did not simply use a wrong shutter setting when filming. How is it possible that the playback was smooth if you only get 15 fields of temporal information when shutter is set to 1/15th at 60p (because frames get quadrupled at this point) ? This thread is a waste of time.
 
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