Rolling Shutter, has it affected you?

[Tim Polster]

Hello,

I would like to get some feedback from EX-1 users on the topic of the "Rolling Shutter" issue.

I watched this clip - http://sonyxdcamex.com/content/view/27/2/
recently and wanted to know if this shows up very often in your use of the camera.

The video of the fence looks pretty drastic to me.

I often film live events with changing lighting as well as some possible sports shooting.

Is the EX-1 really best for low motion and non-flickering lighting, or is the fear outweighing reality in your experience.

Thanks for your input!

[Steve Phillipps]

Well I think it is, but others seem to disagree, check my thread http://dvinfo.net/conf/showthread.php?t=121618
Steve

[Alister Chapman]

I've never noticed it with any live motion, even rapid pans, shots out of car windows at highway speeds etc have all looked OK. I'm not saying it isn't there, but what I am saying is when viewed normally I just don't see it.

Strobes and camera flashes do cause some odd half illuminated frames, this is more noticeable yet it hasn't made any of my footage unusable. I shoot a lot of lightning and the majority of my lightning shots have been OK, maybe 1 in 10 are spoiled by the shutter. The flip side to the coin is that without the portability, and ruggedness of the EX1 many of those lightning shots would have been impossible to get.

For me rolling shutter is there, I know, but it's a small price to pay given the generally very high quality of the footage I am getting from my EX1.

[Steve Phillipps]

This is what surprised me, I just can't understand how anyone could fail to notice it. No issue even on whip pans? I was even seeing it as distracting on fairly slow moves. And when following birds in flight I found it totally unuseable. Surely no-one could look at the test on the link you provided and not think it was an issue? To my mind it's re-assuring in one way as it shows how such a high spec camera can be released at such an amazing low price - because it's got a fairly big comoromise.
For certain uses, though, as I've said, the motion thing won't be much of an issue, and in those situations the image is truly sensational, probably the best still frame grab I've ever seen from any video camera.
Steve

[Mike Stevens]

SEE the flicker post. Lets not loose the oppertunity of airing this with a two post dilution.

[Alister Chapman]

Steve, I think one of your issues is that you are looking at 60P images played at 25P then displayed on a 60P computer LCD or a domestic LCD monitor with bob deinterlace giving you all kinds of weird interpolation issues. Try 50P next time, I'm sure you find it smoother.

As I said when played normally I don't see anything that looks bad. Sure if you analyze frame by frame it's there but in real world use I don't find it an issue.

[Steve Phillipps]

I see it at its worst on the camera LCD. Have tried 50P too. Also see it to a much lesser extent on 50i. And for flying birds etc. it's not minor, it's HUGE.
Steve

[Alister Chapman]

Yes but when your in 25P mode the LCD runs at 50hz so if you shoot 60P you will see judder as frames are being dropped. Switch the camera to NTSC mode and you'll get smooth playback because the LCD runs at 6oHz.

[Steven Thomas]

Originally Posted by Steve Phillipps

This is what surprised me, I just can't understand how anyone could fail to notice it.

Steve, the problem with your thread and as everyone who read though it, you clearly stated your problem as judder and offered no sample of what you were seeing.

This is a CMOS rolling shutter artifact known as "skew".

Not many EX1 owners will care since they already know about this issue under rapid pans. Again, ALL CMOS rolling shutter cameras have this issue, not just the EX1.... It's nothing new.

Someday, there may be advances in this CMOS shutter design that may allow a faster sample rate.

[Tim Polster]

Thanks for your reply Alister.

I posted this because I have never used a CMOS video camera before.

The EX-1 looks like a great camera, especially with a Flash XDR attached.

But, if I am going to dislike some situations, I want to be fully aware so I can have a CCD camera involved if the footage is unuseable.

What would everybody say about filming live sporting events with the EX-1?

[Steve Phillipps]

Phantom HD does not exhibit it from what I've seen, but otherwise, yes it seems that it's the rolling shutter that causes the problem. If the official term is "skew" then fine, but it was a new one on me, and I just percieved it as a general jerky movement of the background, so apologies for not knowing the correct term and causing confusion.
Steve

[Dennis Joseph]

Originally Posted by Steve Phillipps

This is what surprised me, I just can't understand how anyone could fail to notice it. No issue even on whip pans? I was even seeing it as distracting on fairly slow moves. And when following birds in flight I found it totally unuseable. Surely no-one could look at the test on the link you provided and not think it was an issue? To my mind it's re-assuring in one way as it shows how such a high spec camera can be released at such an amazing low price - because it's got a fairly big comoromise.
For certain uses, though, as I've said, the motion thing won't be much of an issue, and in those situations the image is truly sensational, probably the best still frame grab I've ever seen from any video camera.
Steve

I have seen the rolling shuuter effect especially in tele zoom. Although it is not too bad when doing very quick pans from point a to point b when wide or slightly zoomed.

[Steve Phillipps]

Tim, for what it's worth, here's a mini review of how I found the EX1 while I had it for a few days.
The build quality is pretty decent, a lot of plastic but feels sturdy enough. Most of the switches are small and fiddly and can get knocked accidentally. Picture quality is sensational by any standards. Manual lens controls are all excellent, just like proper broadcast lens. The focus ring is a little narrow though, but nice and smooth. LCD screen is nice and seems good resolution but impossible to use it in bright light. Viewfinder is atrocious, impossible to pull focus accurately. Switching between 1080/720 modes and variable speed is a menu job and a real pain. Lens seems pretty good, though starts to lose detail rapidly after f5.6 through diffraction (from my limited tests of it). There is a peaking function to help focus but I found it useless, not a bit like peaking on "pro" cams. There are some nice features such as shutter angle settings rather than just speeds, and a luminance reading function that tells you the brightness of the centre spot in the frame (like "Y Get" on Varicam) both of which are really cool features and didn't expect them on cam like this. Batteries last forever - I had the bigger ones (though still light and small) and they last about 5 hours or more! The whole SxS thing seems to work well, slots are out of the way and discreet but easy to access.
All in all, I would DEFINITELY have bought an EX3 and Flash XDR if not for the motion thing.
Hope this is of some use.
Steve

[Charles Young]

If you have ever worked with high speed cameras you know artificial lighting sources are a huge problem. If the light source is not DC you will probably get some degree of flicker, or dark frames. If the source is a mercury vapor, metal halide or fluorescent, the flicker will probably be unacceptable. Even a tungsten lamp will dim during the zero crossing of the cycle, although usually inperceptable because the filament doesn't have time to cool off much.

A little understanding of how the CMOS works helps to avoid situations that can lead to undesirable images. Eliminating them totally can only be by choosing a different sensor, ie use a CCD camera.

[Steve Phillipps]

For anyone who hasn't read it yet this http://dvxuser.com/jason/CMOS-CCD/ is a very good article by Barry Green. Not much of an issue?
Steve