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!

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

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.

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

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

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.

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

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.

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.

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?

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

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.

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

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.

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

Well this is the problem.

We as freelance videographers and business owners do not always get to choose the surroundings in which we have to operate a camera.

My main point of this post is to try and surmise if the issues are showstoppers are quick, non-attention drawing blips.

When I test the camera at a shop, it is hard to recreate live events ect...

This is a tough position.

Myself and Steve Connor shot an airshow at the weekend with an EX1 and an F350. I just been checking through my 60fps EX1 shots of Spitfires and the Eurofighter Typhoon and I can't see any issues. Even when following the Eurofighter with ground rushing through the shot the motion looks normal to me.

I'll post some examples from both cameras on my server tomorrow.

Showstoppers for me! Go into a shop, put the camera on a tripod in 1080/25P and pan fairly fast back and forth and you'll see the effect in the LCD. Put a Z7 on a tripod in 1080/25P and it'll be different. If you do, let us know if I'm right - I'm prepared to be wrong, but fairly confident!
Steve

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


Tim, I just got back from filming a bunch of Motocross racing and the footage is spectacular...Especially the 60p slow mo shots. I performed some quick pans both on tripod and handheld with no issues. I shot 1080p and 720 24p overcranked to 60p.

Steve, I think everyone understands that you don't like the way the EX1 looks. Let me post some clips so that others can make their own judgement.

Using the built in LCD to make picture quality judgments is not clever. The EX1 LCD is known to have flicker of it's own, most visible when shooting in bright sunlight. To judge the true quality of an image you need a known reference monitor that can accurately and correctly display the images you want to compare. You should display all your comparative material on that same known reference monitor at the same time, under the same conditions. To suggest going into a shop and spraying cameras around with fast pans at 25p and then to say one is better than the other on the basis of images displayed on 2 totally different LCD's with different characteristics is nonsense. Why do you feel the Z7 will be so different? they both use CMOS sensors with the same Exmor technology.

Sorry Alister, I thought the Z7 was CCD, my mistake. OK so try it with a JVC200 then. I can clearly see a very disturbing effect on pans on the LCD.
You may have a point about the LCD screen too, though I'm not trying to judge picture quality, just the motion artefacts. Unfortunately I'm not in a position to view it on HD monitor or in edit suite at the moment, and I know that would be preferable. But I noticed this issue independently of reading anything about it, then looked into it and found that it wasn't just my imagination.
I am a bit perplexed by the whole thing, and would love to be wrong, but what I saw was very worrying for the sort of work I do. I haven't tried a Z7, but I know that doing the same shots on an HPX2100 did not produce results like that at all, they were totally as I would expect them to be.
Steve

Lets see what Alister manages to post shortly, following a Eurofighter Typhoon at 300 miles an hour should produce the effect Steve is talking about shouldn't it?

Definitely, as long as it's got some background. Can I add that it's not true to say that I don't like the images from the EX as Alister suggests, I do. In fact I would even go so as to say that I thought single frame grabs that I took were possibly the best I'd seen from ANY video camera, bar none, well up there anyway.
Just look at the "owrst case scenario" tests that have been done, though, and no-one can deny that there's a noteworthy issue at the least and a fatal flaw for some. Have you seen the helicopter hot in Barry Green's article?
Steve

The shots should have good amount of cloud background as well as the grass airfield in frame also.

I prefer to judge things from my own experience, not other peoples "articles"

Thanks for your replies so far.

I am looking forward to seeing the footage.

This issue is important to us all, so maybe we can get to the bottom of it with this thread.

The shots should have good amount of cloud background as well as the grass airfield in frame also.

I prefer to judge things from my own experience, not other peoples "articles"

I agree 10,000,000%.

No, it's an issue...
It's just that it's real old news for many EX1 owners.
Hence, minimal replies.

Again, there's cameras that cost 3X the EX1 that have the same problem and they are used in highend production.

By the way, Barry Green (who wrote the article you referenced) also owns the RED ONE which has the same issues, but a tad less than the EX1.

This is a very interesting discussion, and I thought I'd drop my $0.03 in - totally agree with Alister; in real life situations / shooting scenarios, I never ONCE came across results that would be unacceptable because of the rolling shutter nature of the EX1 sensors. Also, the other "problem" so often discussed - the motion stuttering in 24/25p modes being allegedly more pronounced with the EX1 than with other comparable cameras - has never been any of a problem to me, ever since I learned my camera movements must be really slow (or the subject followed, with background deliberately blurred with the help of correct shutter speed and/or controlled DOF).

I posted that footage when I got my first EX1 last November, the shot was set up to show if the the rolling shutter 'skew' effect existed in the EX1 which was one of the first to be sold.

I can honestly say that since then I have never encountered it again, maybe it's just the way I shoot, fast pans like that for me are very rare, and when you do perform them the chance of seeing the effect on background imagery is quite slim. Any pans when shooting in 24/25p require slow movement to avoid juddering (strobing) anyway.

Paul.

I have owned an EX1 since Feb and so far done a few events and wedding. Overall I am quite satisfied but not so on the handling. I always have sored thumb after holding it for a full day. The rolling shutter has not been an issue also except for the partial flash exposure which can be easily corrected by overlayed a 50% opaque white frame. Although this is easily done, but takes another 10-15 minutes of my time especially when rushing to complete the morning montage.

my 3 pence (inflation)

If i look frame by frame i can see the skew very easily but for the most part during those times the motion on screen is too fast/too blurred to really catch you out. So, whilst technically it is an issue, aethestically it's been fine so far. I was one of those very concerned before i bought the camera.

But if you're on telephoto, tracking small objects against the background where the object changes direction quickly i could see that being a problem because the skew would change from one angle to another and the background wobble.

Of course i've need to do some sky replacements and roto work from handheld footage soon, maybe i'll change my tune after some serious work....

cheers
paul

No, the rolling shutter hasn't affected me. I'm not sure that there is any point to the question. If your crime scene is illuminated by police strobes -- could be a problem. Panning? No problem. Skewed backgrounds? No problem. If you don't like some aspect of a camera, don't buy it. Get a film camera, they're really much better.

Steve, The Phantom HD does have some of the same rolling shutter problems, it's just much harder to make it happen. The D20 uses the same method where it samples the sensor in 4 quadrants into a frame buffer, this effectively hides the rolling shutter characteristics, but these cameras are in a totally different price range. The D20 is not for sale, and the Phantom retails for 20 times the cost of an EX1, without any lenses or accessories. I'd love to see a sample of the problems you're having as I don't think it's rolling shutter related.

-Sean

Have you seen the helicopter hot in Barry Green's article?
Steve - I think Barrys article does a very good job of explaining the differences between global and rolling shutters, but all rolling shutters aren't equal. Hardly surprisingly, ones in expensive cameras are better than ones in cheap cameras. That's not to say the effects don't exist, but an effect demonstrated on one rolling shutter camera doesn't necessarily imply it will be as bad on another.

I can only second the comments about not judging via the LCD screen. Without viewing the footage on a good monitor, how can you be sure any problem isn't with the LCDs portrayal of motion?

Had a small problem yesterday with the rolling shutter. Filmed a wedding and had problems with camer flashes. Easy to fix by using a plugin to mask the shutter problem. Just a labourious task going through the footage and finding all those flashes though!

Sean, used the Phantom HD a fair bit and never had a problem, but as the exposure time will go down to 1/500,000 second, presumably the shutter must be pretty efficient!
David, I see the same effect on LCD screen, TV screen and MacBook Pro, but I do agree it would be better to be certain if looking at HD monitor or powerful FCP suite.
Steve

Seems like a lot of owners do not see this as an issue.

This is encouraging.

I have shot over 200 hours on my EX1 and the only shots that were effected were some lightning shots... Extremely happy with my EX1.

OK I've put some clips on my server from the weekend.

http://www.ingenioustv.com/clips/dx-overcrank.mov

Sorry, it's not the Eurofighter doing 300mph but a Spitfire doing around the 100 to 200 mph mark. I chose these shots as they include lots of background, the first shot even has an antenna mast in the background. These were shot at 60fps.

To me it looks fine. Feel free to make your own judgements. Thanks to Steve Connor for allowing me to post these clips.

Interesting Alister, that's pretty much the effect I've seen and it looks a bit jittery to me, look at the last shot and the background and foreground stutter rather than being totally smooth. But if 99% of the people that view the clip say it looks perfect then maybe I am going mad after all!
Thanks for posting, and sorry I'm not able to do the same.
I agree with what's been said above, in that I wouldn't advise anyone against buying this camera, but to look at it themselves and shoot some of the stuff they shoot and make their own decision, but I don't think there's any harm flagging up an issue someone's observed in order that a potential buyer can keep an eye open for it. Hopefully no-one in their right mind would spend thousands on a piece of kit either a) without seeing how it performs for themselves, or b) just based on web chit chat and here say.
Steve

Alister, thank you for posting these clips and helping out!

My impressions where different depending upon how I watched the clip.

Inside of Quicktime, the motion is stuttery, but when I put it in Edius and played it out to my production monitor, all of the stuttering went away.

Bear in mind that especially the first clip where a lot of ground was being covered, even at 60 fps, the pan speed is going faster than the framerate can handle. This is even further displayed when the footage is slowed down.

I would say judder or skew is absent from these clips from what I see here.

At full speed, these issues would not even enter the mind.

Thanks again!

Looks like flashes might be the only cryptonite to deal with.

As always you have to be careful not to confuse stutter caused by playback problems with anything real in the clip. To my eyes all the clips from the airshow look as I would expect for 60P and 25P.

Strobes, flashes and some lightning can cause a problem with partially lit frames. When I shoot lightning I use the slowest shutter I can and the vast majority of my clips are fine. I did a wedding with lot's of flashes going off and there were quite a few half exposed frames, but the client didn't notice them when he watched the video.

I've experienced rolling shutter shooting lightning at 25fps, any solutions?

2 frame SLS and 25P works well for me with lightning.