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Global Shutter - is it possible for RED?

P

Peter Hebert

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I noticed on DALSA's site they mention a global shutter on some of their OEM cameras that use CMOS sensors. I was not aware that this was possible - every online resource I have read say that rolling shutter is inherent in CMOS sensors. If this is possible - could we possibly see a true global shutter sensor on RED cameras at some point. I would like to avoid the jello-vision thing if at all possible.

Global Shutter Imaging - DALSA

Forgive me if this has been addressed already.
 
phantom and weisscam both use global shutters. not sure about other cmos cinema cameras but i suspect so as well. global shutters are IMMENSELY expensive. that's why these are 150,000 dollar cameras. has a lot to do with heat dissipation and creating it just right for low noise, high framerates, and high resolution. but cmos technology itself is getting better by the hour, it's all a matter a time. i mean 4 years ago who would believe you could have a fully functional 4k digital cinema camera for the price of a ENG camera?
 
I wonder what the numbers are for the other prosumer DSLRs, it would be very interesting to know.
Does a global shutter mean 0µs?

Is there a way to measure this on other cameras?
Who's got a skew chart?!
 
Canon DSLRs are known for their slow rolling shutter. Which seems to be more or less due to their high resolution sensors (21/18MPix)- more pixels - longer readout cycles (generally speaking).

I haven't seen numbers, but quite some Canon DSLR rolling shutter test-footage. Some of which looks pretty funny...
Not a problem though for their stills abilities, since they still ,-) have their very fast mechanical shutter.

Also, Sonys EX1/EX3 are notorious for their 'relatively slow' rolling shutter (compared to other 'video cams').

EPIC is twice as fast as R1 according to RED. It still could become a problem from time to time with motion as well as stills I guess.

I'm wondering wether the rolling shutter speed is identical on RED cameras for all framerates? A Chip going 150 or 250 fps MUST have a faster rolling shutter than one maxing out at 60fps - again, generally speaking?


- Carsten
 
Being a Canon owner, I can tell you that the rolling shutter sucks. But I'm wondering what the actual sensor read time is where you can start to see the artifacts. Clearly there are some major artifacts on the Canon 5DmkII. According to Stu Maschwitz on ProLost, the New Canon IDs mkIV has made great strides in that regard. So much so that they shot handheld w/ whip pans for a recent camera test.
 
Anyone know if the read-reset time will decrease with the introduction of the Mysterium X sensor in an upgraded RED ONE?
 
Think about the size of a 28K sensor. As the sensor size increase then at some point fighting the rolling shutter stops making sense and the global shutter becomes an imperative. So mark me down, I'll put money on Monstro being global.

Anybody like to bet?

IBloom
 
The read reset time on the R1 is the same for all frame rates.

The fps and shutter speed determine the amount of time that passes from when the photo-sites get turned on till when they are turned off.

I will bet that monstro will still have a rolling shutter and might sit at the 4 micro second film equivalent. If the rolling shutter can get across 28k in that time then the skew should be no different than if it got across 5k in that time.

Either way the line at the bottom of the frame was activated 4 microseconds after the top line was activated.
 
Terms accepted.

You can all bear witness. Ian and I have ourselves a wager.

50 euro on global versus rolling.

Now is this on the monstro line or just the 617?

:emote_popcorn:
 
I Bloom said:
Whole line.
Click to expand...

I'll put a candybar on the line for that. (By the way I still owe someone a candybar.)

I hope you're right but I find it extremely unlikely. Then again... we still have no schedule for monstro... so maybe in 10 years. ;)
 
What do you suggest as a read-reset test setup? It's easy to demonstrate it, but what is an easy to replicate setup to measure it?

- Carsten
 
Still wondering how one would test the read-reset time.
What if you had a spinning bar or black/white quad, that spun at a known rate?
Would the amount of curve in the bar represent the skew in a quantitative way?

-Tom
 
Tom Frisch said:
Still wondering how one would test the read-reset time.
What if you had a spinning bar or black/white quad, that spun at a known rate?
Would the amount of curve in the bar represent the skew in a quantitative way?

-Tom
Click to expand...

Shoot a spinning fan at 4K, 3K and 2K all at a very tight shutter angle. Then crop all of your images to 2K and compare.
 
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