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View Full Version : Sony XDCAM EX - Is Rolling Shutter Bad For Me?



Cam Carrithers
01-30-2008, 09:54 PM
This thread is for anyone who knows a lot about the HVX-200 and Sony EX1.

I want to get the Sony EX1 because I like the look of the camera better than the HVX, but I am very concerned about artifacts from the rolling shutter effect from the CMOS technology.

Would it be a bad idea to purchase this camera for my purposes? I shoot a lot of hand held documentaries, live music in clubs with various stage light, and music videos. That said, do you think getting the EX1 would be the wrong camera for me?

Thanks for reading this. Cam


Cam Carrithers
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Lenilenapi
01-30-2008, 10:47 PM
Cam there is an enormous amount of discussion about these issues on this website and at DVInfo.net . You should research this yourself because people have various opinions and there are many pros and cons. To summarize here would just duplicate.

The biggest problem I think you will have with live events at night is flash from still cameras, or any kind of strobe affects in clubs. Those may look hideous, but you need to draw your own conclusions from the evidence.

Lenny Levy

Cam Carrithers
01-30-2008, 11:25 PM
Lenny, thanks for the info. The camera flashes and strobe-type stage lights seem like the biggest contributor to the effect from what I read. Do you know if regular (red, green, and blue) flashes of stage light would cause the rolling shutter effect on cmos cameras?

Lenilenapi
01-30-2008, 11:37 PM
If I were you I would rent an Ex and then test it in the most demanding situations you could imagine for it . Then tell us what you find out.

I have seen pretty repulsive flash effects from the Ex (on the web) and talked to some people who were in situations where photo flashes were going off that didn't affect it at all.

For me parties etc are not that critical , though I do get those jobs and it would be nice to know more about the problem and if there is a way to fix it in post. The only way I can imagine though is to completely white out 2 frames or so. That sounds kind of ugly. But maybe someone can figure out something more elegant. Maybe you could blend the overexposed frames if the partial frame exposures line up, but I'm not sure they do.


I await your test reports.

Lenny

matthew77
01-31-2008, 07:50 AM
Lenny, thanks for the info. The camera flashes and strobe-type stage lights seem like the biggest contributor to the effect from what I read. Do you know if regular (red, green, and blue) flashes of stage light would cause the rolling shutter effect on cmos cameras?

Stage light won't do it - especially tungsten ones. It happens with very fast strobes only. Things faster than 1/30 second in "warm up time" I would estimate will cause the problem.

Even LED based police lights, which look like strobes, but aren't, don't cause the effect. Strobe based lights definitely cause the problem.

I also recommend you test.

Lenilenapi
01-31-2008, 08:36 AM
Even LED based police lights, which look like strobes, but aren't, don't cause the effect.


There is a shot of a police car at night somewhere on the web with a spinning light on top that is driving the Ex shutter crazy.

Is that the police lights you are talking about?


Lenny Levy

matthew77
01-31-2008, 08:50 AM
Those are xenon strobes - I was referring to LED based lights.

The point I was trying to make is that it takes a very fast strobe to create the problem and that LED based lights, even though they look fast like strobes, are not fast enough cause the problem. So most stage lighting will be similar - it may look fast but it's not going to be fast enough to cause issues.

I shot a test of the LED police lights and examined them frame by frame - no partial exposure.

Stevet
01-31-2008, 10:16 AM
Lenny, thanks for the info. The camera flashes and strobe-type stage lights seem like the biggest contributor to the effect from what I read. Do you know if regular (red, green, and blue) flashes of stage light would cause the rolling shutter effect on cmos cameras?

I'm not sure on which stage lights cause a problem with the EX1. I have moving heads (MSD Lamps) which have a strobe function (mechanical shutter). I see no issues shooting these during strobe or any other of their functions.

PhilaDvXphia
01-31-2008, 01:38 PM
matthew,

Is there any way that you can you post that test footage? I have a shoot coming up where I need to have police lights and I'd really appreciate it if I could see your test before I actually buy the camera. Thanks!!

Cam Carrithers
02-04-2008, 10:36 PM
Lenny, thanks for the info. The camera flashes and strobe-type stage lights seem like the biggest contributor to the effect from what I read. Do you know if regular (red, green, and blue) flashes of stage light would cause the rolling shutter effect on cmos cameras?
Does anyone know if rolling shutter effect artifacts are present when camera stobes are used in already well-lit rooms or well-lit outdoor events vs low light situations like in a night club or bar?

In short, does the amount of available light in the place you are shooting determine if the rolling shutter effect artifacts will happen with strobe type lights? I.E. If camera strobes are popping all over an already well lit room, would the rolling shutter effect artifact still happen? Or would the artifacts only show up when flashes are popping in a dark room?

matthew77
02-04-2008, 10:58 PM
it's all relative.

If the room lights overpower the strobes by a lot, you'll see no effect.

If they are equal brightness you will see the effect as a partially exposed area one stop brighter than the rest of the frame.

This is all theoretical, but basically the brighter the flash relative to the ambient light, the worse the effect.