More stuttering zoom stories....
 

Many of you are already familiar with the stuttering zoom issue present with some ex cameras. There have been posts here and on other boards describing it, with various responses from Sony. I provided a fairly detailed description in this thread some time back;

http://www.dvinfo.net/conf/sony-xdca...-normal-2.html

This has become an on-going issue with the ex3 that my business partner and I initially purchased in early July. I think we’re on camera number 4 now, having opened up at least two other boxes with new cameras. In short, slow- to mid-speed zooms cannot generally be executed without a pulsing or stuttering action of the lens under constant rocker pressure. In attempting to work around the problem I’ve found that ramping past the slow-zoom range in the rocker position (ignoring the initial stutters), trying to settle on a steady mid-speed zoom will also fail. It’ll work for a moment, but then the zoom speed accelerates (without further rocker pressure) and starts to get away from you. Reducing rocker pressure at this point brings you back into pulsing and stuttering territory. I cannot properly express just how frustrating and embarrassing it is to lose shot after shot like this. Sony is aware of the problem, as they have offered explanations to us either on the phone or in person. But when it comes to their official responses in regard to a specific camera they will not acknowledge that the camera malfunctions.

We took the first camera back to the dealer and put it on their tech’s bench to demonstrate the problem. The dealer immediately suggested that this was a problem that occurred only at 24p, as he had already been given an explanation by Sony before we ever brought it to his attention. This was not the case, as we were able to reproduce the problem then and there at 1080/24p, 1080/30p and 1080/60i. Our dealer sent the camera to Teaneck for repair and Sony sent the camera back indicating they had given the camera and lens a thorough going-over, but acknowledged no malfunction. Obviously a camera that can’t zoom properly is not only a liability, but is pretty much useless for most kinds of work. When a director or producer asks you for a slow zoom, telling him/her that your equipment isn’t capable of it isn’t acceptable. The dealer understood, and we opened up two more boxes to find each new camera exhibited the same problem. We gave them back the camera.

We went to Abel Cine Tech in hopes of finding a functioning camera, and with the hope that if we had to send the camera to Sony again that Abel might have sufficient influence to illicit better attention. In the meantime we had bookings for the camera, so we had plenty of opportunity for real world field tests under different kinds of shooting scenarios. We really wanted to make each camera work, perhaps more than we reasonably should have. If you’ve spent any time working with this camera, maybe you’ll know why.

In fact, on our first visit to Abel there happened to be a Sony rep there. We demonstrated the problem present with the new cameras, then demonstrated its absence in Abel’s floor model. His response was honest, but I was amazed to hear him say, in effect, what do you expect? Their Cine Alta division is manufacturing a $9000 camera, you can’t be surprised if the manufacturing tolerances are a bit off. Maybe they’ll do a better job with the next model iteration.

After working with the new camera for a time we took it back to Abel and told them the results. They asked that we try the repair route again before another exchange, and we agreed to try it. We spoke with the tech who worked on the camera at Teaneck and he indicated that he would replace the front element in the lens. We also spoke with another Sony rep during that time and he brought up the explanation involving the 24p malfunction. Apparently this has something to do with an excess of data overwhelming the processor while zooming in 24p. Obviously he hadn’t actually tested this theory himself. And why would this lead a tech to replace a lens element? We got the camera back with Sony’s assertion that function was normal. We tested the zoom with a variety of video format settings, and it still didn’t work properly.

The staff at Abel have been very helpful and sympathetic. I don’t know what conversations might take place between a dealer and a manufacturer, but there doesn’t seem to be anything they can do. Our options seem to be either keep hoping we’ll eventually get a properly functioning camera, or we’ll just have to hand them the camera back and give up on the ex3. It’s disappointing. We really want to move forward with the ex3, but you can’t invest in a camera that makes you look incapable of executing standard camera moves.

I still can’t get over the idea that you can go out and buy a $300 video camera and it will zoom properly, but that Sony might hope to suggest that this malfunction doesn’t take the ex cameras outside the realm of fitness for purpose.

Could it be an issue to do with the rolling shutter?
Steve

At one of the Experience events someone mentioned to me the stuttering zoom. I never use the zoom rocker, only the manual zoom. So I had a go and found that yes, the EX cameras do indeed have a stuttery servo zoom. Nowt to do with rolling shutter. The servo zoom simply isn't smooth. At higher speeds it isn't noticeable, but you can't do an effective creeper zoom.

Personally, it looks and feels on my EX1 that the lens mechanism is sticking, rather than the actual servo motor acting 'lumpy'. It only seems to happen on zoom ins, and only at medium to lower speeds.

It's such a light zoom mechanism that the servo isn't really having to work hard at all. And it's probably plastic on plastic inside.

I don't own any full size cameras, but I've used lots of them and their manual zoom always feel quite a bit stiffer on 'proper' lenses. I can't get a smooth manual zoom on the EX1 because it's so light to the touch, but it's easy on 'proper' lenses.

If the mechanism was stiffer with a little more friction the zoom movement would mechanically smooth out and result in a smooth optical result. Perhaps some heavy grease carefully placed on a particular moving part would give the servo a bit more work to do, and make the zoom mechanism a little heavier/smoother?

It's apparent that it isn't related to the shutter. If you watch the zoom ring while attempting a slow zoom you can frequently see a regular, rhythmic pulsing, which suggests some sort of interaction between the electrical signal and the mechanical elements. And that also demonstrates that it isn't simply a matter of not knowing exactly where the threshold is on the rocker, as is the case with some of the smaller cameras.

Also, the problem isn't present when you put a larger eng lens on the camera. Those lenses will function just as they always do, as they bring their servo mechanism along with them. However, you can change out other ex3 lenses (from properly functioning ex3's), and the problem will stay with the camera.

Abel's floor model works pretty well. That is, you can sometimes notice slight hints of the problem, but it's functional. The cameras we've had, that can't be said about, no matter how hard we've tried to work with them. There is simply little or no control of what the zoom is doing.

Well in that case then fair enough, as someone else said you can put it down to the fact that the camera is so cheap and so you can reasonably expect it to be below par mechanically in certain areas. The optics of the supplied EX lens are really very good, and yet the whole camera is about 1/4 of the price of just a lens for an HD broadcast camera!
Steve

That's an interesting take. I don't generally expect anything i buy to be sub-par mechanically. If i did, i wouldn't buy it. What if it dropped 3 seconds of footage out of every minute? How would your interviews turn out? Are you still ahead of the game at only $9000? If i offer to pay a bit more, can i get the full minute?

I don't think it's unreasonable to expect the camera to be able to zoom properly.

Yes, but for example you get better build quality with a pro Nikon than you do with a domestic one. Same with a Mercedes vs a Kia.
Steve

That's certainly true. But they all meet a certain minimum standard. Even the Kia. Maybe not everyone's work requires proper control of their zoom. Maybe it isn't an issue for you. But there is such a thing as fitness for purpose. Do you think it's unreasonable to expect the camera to zoom properly?

No, I think it's a fair point. Good luck coming up with a solution.
Just thinking, when shooting film we had zoom dampers clamped on the lenses, so giving a nice fluid (manual) zoom. Don't know if that's an option, but I think a servo zoom is so expected these days that most people would demand and (I suppose quite rightly) expect it.
Steve

Thanks Steve. I'm hopeful that we'll get it sorted out.

No compact or prosumer camera , whatever we call them, with a fixed lens is capable of a truly smooth zoom on par with lenses for 2/3" or 1/2" full size cameras. I've been saying this for ages on line and someone always replies, yes they can or its smooth on their camera. Anybody who believes this is not familiar with the true feathering, ramping, creeping, whatever you want to name it, capability of lenses for full size cameras. PD150, PD170, Z1, DVX, HVX, EX etc. none of these can achieve truly smooth zoom speed variation at slow speeds. Absolutely none can feather or ramp, that is, starting from a static frame and ramping up to the slowest zoom possible with the degree of subtlety nearly imperceptible by the average viewer. We use this sometimes to detract as little as possible from the subject in frame. And maintaining this speed or varying it, with the same subtle degree of adjustment, through three quarters of the zoom range for example, never stopping.

Most dealers are lost for an answer. The easy answer is the old you get what you pay for line, which is a convenient answer and one that completely misses the point. Most will come up with an answer to not look clueless. This should not be regarded as normal just because all these cameras suffer the same problem. This is a defect. One that they all share for as you say it does not satisfy fitness for purpose. A video camera can not be sold as or considered professional if it can't zoom properly.

The day someone opens up the so called servo module in one of these and posts comparison pictures against a lens for a full size camera is when this will be proven for the inexperienced. Or just find the explosion drawings from the service manuals. I do not think this is a manufacturing cost issue. You can find cheap stand alone lenses with proper servo. For 8k to 10k you should be able to provide a proper servo in a compact camera.

One explanation, one that might fit across the board, is that they are all electronic. That at low rocker pressure there is intermittent voltage passing through to the lens electronics. For lack of a more scientific comparison let's call the full size lens servos mechanical and the compact camera "servos" electronic. These fully electronic servo-lens interfaces are faulty through and through with all these cameras.

It has befuddled me for so long that manufacturers and users have been insensitive to this stuttering zoom plaguing compact cameras that I have given up. My solution is to avoid zooming with these cameras unless its a fast zoom with hard start and stop.

One thing is certain. No manufacturer should call their lens "mechanical" when it's pseudo mechanical.

Even the focus ring on the EX lens is controlled by a servo apparently, rather than a proper focus helical, though the action is quite nice, so much so that I didn't even realise. But yes, Max is right, these things are cheap (relatively) and there is no magic bullet, they have to cut costs somewhere and if you're not going to lose something because of it why would they make them all that way?
Steve

I'm getting my EX3 back tomorrow. It's the second time I've sent it in for the zoom sticking and stuttering at low speeds.

The camera worked fine for months when I got it, then started doing this. Sony repaired it, sent it back and it worked fine for more months, about 6. Then it started again.

Supposedly they have replaced/repaired something on the lens ... when I see the writeup I'll post it.

I don't expect a lens of this price to have the finesse of a much more expensive lens; However, when it has exhibited this behavior it renders the first 25% or so of the slow end of the range unusable. Allowing for cost it's still far short of my expectations. My Ex-1 does not do the same thing.

Are we talking about this problem happening when using only the zoom rocker on the lens itself? I haven't noticed this happening when I use it on my EX-3, but I mostly shoot on sticks and use a BeBob Zoe-EX controller. I frequently do imperceptibly slow pushes using the BeBob and it's wonderful.

It's starting to sound like a design/engineering issue with the lens's rocker assembly. Has anyone who has experienced this problem tried an external zoom controller? If the behavior is different, that tells us a lot.