Ex-1, Shutter Off & Flashes

[Bassman2003]

Hello,

I am researching this camera and have been concerned with how it handles flashes.

From reading posts, it seems if one turns off the shutter, the camera can handle flashes in a better way.

Is this true and how much better???

I plan on shooting a lot in 720p60 and could turn off the shutter when I knew flashes would be present.

Does this mean I would still get a shutter of 1/60th because of the 60p framerate?

Thanks

[gabrielflorit]

Um..... this question has been asked many many many times before. Do a little search on this forum.

Shutter speed has no bearing on the flash issue.

[Bassman2003]

Thanks for your reply Gabriel.

From what I have read, turning the shutter off makes the EX-1 function with a global shutter instead of a rolling shutter.?.

This is supposed to handle flashes better.

I am not speaking to increasing shutter speeds, just turning the shutter off.

Please inform and correct if I am wrong.

[Barry_Green]

From what I have read, turning the shutter off makes the EX-1 function with a global shutter instead of a rolling shutter.?.This is not true. The rolling shutter is a rolling shutter -- don't think that there's any easy way around it.

According to Matt Jepsen of FreshDV (http://www.freshdv.com/2007/12/xdcam-ex1-cmos-rolling-shutter-strobe-artifacts.html), who posted some of the early strobe footage:
Quite a few people wrote in to tell me that the issue reportedly goes away when the electronic shutter is turned off. So I tested the camera with a flash in all the different formats, shutter ON vs shutter OFF. Here are two studio test framegrabs that show this issue less prominent but still present in 1080/24p footage with the shutter mode toggled off. The downloads are full-resolution frames exported from FCP timeline as jpeg-12. I haven’t spent much time digging into the footage, but the camera looks to be catching probably 40% or 50% of the flashes mid-roll. Small flashes that don’t light the whole frame slip through more easily it seems. So maybe 1 out of every 2 don’t appear to get caught.

[Bassman2003]

Thanks Barry.

Just looking for some hard facts about this.

I am frozen with an HD camera choice as I am uncomfortable with a camera that can not handle a strobe environment as I often shoot live events.

What I want is basically too expensive!

[NoahK]

Thanks Barry.

Just looking for some hard facts about this.

I am frozen with an HD camera choice as I am uncomfortable with a camera that can not handle a strobe environment as I often shoot live events.

What I want is basically too expensive!

The EX1 can definitely cause issues in an environment with strobes- like say a wedding. That said, the rolling shutter flash is visible mostly to the trained eye, frame by frame. Most folks won't even notice it during playback and it's pretty easy to correct for with a bit of matte color in post if you really object to it. It's kind of one of those things that's a lot more scary sounding than it truly is in reality. If you wan to know a bit more, here's some demo footage of what it looks like:

http://www.freshdv.com/2007/12/xdcam-ex1-cmos-rolling-shutter-strobe-artifacts.html

If it is a problem for you, the next most logical camera would be an HVX200A or one of the Sony HDV cameras. Also Canon's- though to be honest those are a bit outgunned by the HVX and EX1.

Noah

[Bassman2003]

Thanks for posting this.

It kind of bothers me and I can see if this was a bride & groom, this footage would not be useable.

Putting a white frame would not help this footage as the scene does not go all white.

Also, a concert or stage production with an effect or even the many people who use their flash in the audience might create the horizontal separations which do seem to catch the eye if there are enough close together.

Tough decisions...

[sinfear11]

The EX1 can definitely cause issues in an environment with strobes- like say a wedding. That said, the rolling shutter flash is visible mostly to the trained eye, frame by frame. Most folks won't even notice it during playback and it's pretty easy to correct for with a bit of matte color in post if you really object to it. It's kind of one of those things that's a lot more scary sounding than it truly is in reality. If you wan to know a bit more, here's some demo footage of what it looks like:

http://www.freshdv.com/2007/12/xdcam-ex1-cmos-rolling-shutter-strobe-artifacts.html

If it is a problem for you, the next most logical camera would be an HVX200A or one of the Sony HDV cameras. Also Canon's- though to be honest those are a bit outgunned by the HVX and EX1.

Noah

The Canon XHA1 IMHO is the best "Bang for the Buck" value and I would hardly say that Canon is outgunned by the HVX or the EX1. I think both of those cameras have strengths and weaknesses but all of the cameras are capable of producing excellent work. Look at what you are going to be shooting and plan accordingly. If you were going to go with the HVX200A you might want to wait for the HPX170. As far as the EX1 it is a great camera as long as you know the limitations. But for me...I love the Canon XHA1.

[MattDavis]

The rolling shutter is a rolling shutter -- don't think that there's any easy way around it.

Here's some offcuts of EX1 footage that include photographer's flashes. It's not finished footage, just the bits before or after the shot whilst I frame up and focus. It's not about the look of the camera, nor my camerawork. I have even put some text on the movie so people know what to look for.

The movie is presented as PhotoJPEG to preserve quality and to avoid codec issues beyond QuickTime. 14 MB takes time to load. Please be patient. You can use your arrow keys to step through frame by frame, and this is how I intended it to be viewed.

http://www.mdma.tv/ex1/flashes.html

Warning: contains flashing strobes. Fast editing. May cause seizures. May contain nuts.

As I get photo flashes usually when there's little light around, I tend to have the shutter off, and so I don't get a problem. Even when it's on, the effect is not exactly displeasing (the Delft Girls shot for example). It rolls, but not in a way that non-experts would point at and refuse to accept.

Unimpressed? Well, [Jack Nicholson smile] That's my point.

[Bokes]

I hope the footage posted by MattDavis proves that this issue has been blown way out of proportion. I shot several events- with flash- and not one complaint.
The cop car footage doesn't even look that bad to me.
The HVX might handle the cop car flashers better , but it's a low light shot and folks would complain about the video noise.

The noise on the HVX never bothered me.
And the rolling shutter on the EX1 will never bother me.
Just shoot.

[Bassman2003]

Matt,

Thanks for posting this.

I am especially pleased to see the auditorium shots as I am often in this environment.

The flashes from the crowd did not seem to effect the frame, and I will be able to shoot with the shutter off as well.

So you have really helped me as it is difficult to test a camera in this environment without owning it.

Thanks


Bokes,

Your opinions are your opinions.

Blown out of proportion is not how I would classify the cop car footage.

I would be embarrased to hand that over that footage to somebody.

And judging your output based on whether or not clients complain is not how I prefer to operate.

[Bokes]

Bassman
I guess what I meant about the cop car was that it is acceptable in most markets.
I work with and view news footage from all across the country and I see this type of footage all the time. And sometimes much worse. It all makes the air in local markets.
Flashing cop cars are the stuff of ENG and
I find in the world of ENG
As long you get something on camera- There's nothing to be embarrassed about.
My point about no complaints was- if the half frame flashes were an issue we would have heard some negative feedback by now from someone. We haven't.
(We heard plenty of neg comments about grainy low light footage from the HVX.)

[Bassman2003]

It sounds as if we are in different market segments.

If I am going to move the HD and this be my main image from now on, I feel I want to be able to depend upon the footage in as many or all situations I will be filming in.

The HD upgrade has me pulling some hair out because all of the cameras I own are still working fine, but I know I have to do it sometime, and better not to be left behind...

[rainermann]

I shot a lot of events with a lot of flash lights. Of course, we have "trained eyes" and we easily can spot the half frames or so. But never a customer complained about it. I guess most of them don't even get it what we are talking about... even if you try to explain it to them... At least they wuld say "Oh, yes there are a lot of flashes" but sure not "I don't like the half frame exposure...."