Tom, that's true when you put it that way. But then you're forced to make the decision to go with a CCD-equipped cam that's not nearly as good in low light. You then risk a more grainy product which also detracts from the professionalism.

As I've said before, you pick your poison.

Rolling Shutter Banding and CMOS / HVR-Z5U
 

Hello,

I'm very new here, but I pored over everything I could find in these forums and on the 'net regarding problems with rolling shutter and the benefits of CMOS vs CCD (goes both ways, I know), and ultimately ended up buying the Z5 because in every other way, it was the camera of my dreams. I don't really have a plan, or a professional reason for having such a fancy camera (I've still barely scratched the surface of its capabilities--and mine), but I love to shoot, and I needed an upgrade from my collection of beat-up Sony DV and Hi8 camcorders.

I love the camera. It really can see in the dark! This camera has given me a lot to grow into, and the price for the XLR inputs and audio controls, not to mention the other pro features, is well worth it.

However, I have had a couple rolling shutter issues that were somewhat annoying, if not downright disturbing. One was a full-zoom close-up of some lovely yellow birds twittering away on a branch. Another of the same birds flew through the shot, and I could tell, even at normal speed, that there was something wrong. Maybe a non-videographer would not have noticed. This is beside the point. In slow-motion, I could see that the upper and lower edges of the fast-flying bird were truncated by the rolling shutter effect.

I was shooting in manual focus, auto-exposure, HDV 60i, by the way.

The other, more recent and more disturbing incident was during a lightning storm. We've been having these things roll over almost every day, and they afford lots of opportunities for some great image acquisition! I live as far out-of-the-way as you can get (relatively speaking) and my property is an old hydraulic mine and forest. My first HD 'project' is to document this place, its history, and its recovery (both mining and logging have devastated the land. At first when I saw the hydraulicked hills, I was aghast, but they are totally surreal, and in the right light, with the right sky, quite beautiful.

Needless to say, after shooting (on tape) for a good while, during a dry lightning storm, I finally got one that I saw on both the real sky and the LCD simultaneously. I was shooting in manual focus/exposure mode in HDV 60i. This particular single bolt with some forks that I did not notice until I got the footage onto the computer looked pretty OK the first time I saw it at normal speed, but then, knowing what I was looking for, I could see the banding effect. Bummer. When I tried to capture a still of the event, there was not a single frame to use, as the banding obliterates the image.

Now, I thought to myself, perhaps a higher shutter speed would do the trick. Arbitrarily, I tried 350. Well, after viewing what could have been an amazing moving image (the old mine glowing against tall green trees and forest in the late afternoon sun, with blue/black roiling clouds looming overhead, and a particularly close, large, and multi-pronged lightning attack just to the right of center frame), the banding was SO BAD that I could not even pretend it was OK.

I guess the next attempt will be at 24p? Or perhaps I should just reduce the shutter speed to 15? Experiments will ensue.

Long and short of it: I would definitely pay for this camera again. I love the low-light performance, and everything else looks really good. There is no ONE camera for every occasion, and if I get serious, or run into lots of extra money, I would buy a Z1 to use for the lightning. I don't otherwise shoot parties or weddings, or emergency vehicles, but square birds do not turn me on either. It is so infrequent, and the other attributes of the camera make up for it in this precarious balancing act....

Gene Cornelius

Gene, you hit the nail on the head! There is no one camera that can do everything 'better' than every other. But you've found a camera that works better for you than others in the vast majority of situations, and that's the best any of us can hope for.

I was out today, shooting a variety of scenes in an attempt to determine what to take on a cruise & land trip my wife and I are taking to Alaska this summer. I would have liked to have just taken my Sony XR500 since it's small, light and compact in addition to having great picture quality. But when I got home and compared the variety of shots I had taken, the Z5 was simply 'too much better' in a variety of scenes for me to not take the Z5 for a once in a lifetime trip. The exposure latitude, color and overall picture quality will force me to take the 'big boy'. :)

Good for you Ken. I would have taken the woosy way out and grabbed the smaller one.
Should be an awesome trip and hopefully you'll post some clips for us.

You needn't bother Gene (and welcome aboard, BTW). The rolling shutter is the way the CMOS chips are read - line by line - rather than as the CCD is read - by dumping its info all at once. So shooting at different shutter speeds and PS vs interlace won't make any difference I'm afraid.

But your best line is that you're delighted and would buy the camera again. My Z1 lives in a world of electronic flash, lightning forks, police vehicles so I too would buy it again.

tom.

Presumably, manufacturers could buffer the data from the CMOS and read it out frame by frame? I'm sure you could get out a sensors worth of data in less than a 1/50th of a second.

Obviously, it's more complex and costly to build it this way, so the manufacturers will only do this is it becomes a commercial necessity - and if everyone is just accepting of the current rolling shutter issues it probably won't become one.

My guess though is that the rolling shutter artifacts are by-product of the early days of shifting to a new technology - we have to live with it for now, but eventually the problem will be solved, manufacturers will engineer their way out of this issue and in a few years we'll have even cheap CMOS cameras with no rolling shutter issues.

Or a software/firmware stop-gap solution may be on the cards, like we've already seen elsewhere.

I just did a video of a photo shoot on a canon hf11, rolling shutter all over it in varying degrees but none of the parents who have viewed it have noticed until I pointed it out.

Lanchester EP Year 6 five amigo's Photo Shoot 14-6-2009 on Vimeo

I also have a panasonic 301 P2 camera and it will be interesting to see how their firmware update improves the cmos on that camera.

I find the CMOS treatment of electronic flash (almost) acceptable when shown in real time and it's not Paparazzi over-done. It's when the footage is slowed in post that CMOS flashes become (in my view) unacceptable. I'm sure R & D are working on it right now.

tom.

I guess my question is why point it out to them if they didn't notice it in the first place?

If I were you I would have never pointed this to the parents. It's no point. Now it's psychological, when they view the video they will always notice it.

Stelios

Yes - but I think that at the moment most of us are trying things out and working out what is acceptable or not to us, and what is acceptable or not to our clients in what context.

Once we are confident in our choices, then we can forget it and move, and choose the most appropriate tools for a given purpose.

Ben, I would say if the client never noticed it, it's surely not a problem for them. Many people will begin to fixate on a 'problem' if you point it out to them...even if they never noticed it on their own.

I just don't see a point in making people unhappy if they were pleased to begin with.

What if you look at this from a completely different perspective.

With the CMOS family of cameras, Sony and Canon have developed a terrrific new technology to benefit event videographers. With this new technology, when a flash goes off only a small portion of the frame is overexposed, unlike older CCD technology that overexposed the whole frame which complely ruins the frame.

That's exactly how I feel Ken.
"Do not trouble the trouble, until the trouble troubles you"

Stelios

Greg, I've said just that many times! This is part of the reason I've never understood the constant harping on CMOS' obscuring of partial frames. Why were people 'perfectly content' with total frames that were obliterated?

One thing I know for sure is that CMOS does offer benefits that CCD simply doesn't.