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-   -   "Bump" at Beginning of Zoom when using Controller (https://www.dvinfo.net/forum/sony-trv950-pdx10-companion/41137-bump-beginning-zoom-when-using-controller.html)

Chris Long March 14th, 2005 05:06 PM

"Bump" at Beginning of Zoom when using Controller
 
Hi All
This has been mentioned plenty of times, but I've always wondered what it really looks like. Does anyone have an online example of the "bump" that occurs when using a LANC zoom controller?

Thanks
Chris

Tom Hardwick March 18th, 2005 01:54 PM

Not quite sure what you mean by the bump, but of course all LANC zoom controllers can only access the zoom speeds programmed into the lens itself. That's why you can't gently accelerate from rest with any of these servo zooms - including the end-stops+lever FX1 - because you go from zero to the slowest zoom in a micro-second.

tom.

Boyd Ostroff March 18th, 2005 02:32 PM

Tom is right about this, even with a LANC controller you can't go any slower than the servo supports, so there's always a slight jerk. It seems inconsistent to me however, sometimes it's more noticeable but perhaps that has more to do with perception based on the scene itself. If you start the zoom immediately after starting a slow pan it seems to help disguise it.

But perhaps you're talking about the other zoom issue on the PDX-10? When you zoom in or out from the maximum telephoto end of the range then the image goes out of focus for a second, maybe less. It's very annoying - and also somewhat inconsistent - I don't think it happens every time. The only workaround I know of is to try not to zoom all the way to the limit. Turning autofocus on may help to minimize the effect, but it's still there.

Sorry, I don't have an example clip. I can tell you that the same phenomenon occurs both with and without the LANC controller however. FWIW, I use a Varizoom Pro-L.

Chris Long March 20th, 2005 06:56 PM

Thanks guys--I was referring to the zooming, not the focus issue. I'd seen it mentioned in a couple of threads, I guess by Boyd--
like here:
"Unfortunately, it's just the nature of all these prosumer cameras that starting and stopping the zoom always involves a slight bump..."
or here:
"The Varizoom makes this easy, however there's almost always a little "bump" when a zoom-out begins from max telephoto..."
Was just wondering what it was about.

I had assumed that it had something to do with the LANC controller, because it seemed like each time this "bump" phenomenon has been mentioned, it's been in the context of a discussion concerning zoom controllers. But if I'm understanding this correctly now, this is something that I can reproduce using the rocker control on the camera, and not something solely induced by the LANC controller.

Is that correct? If so, I have nothing to worry about--I don't know that I've ever noticed it when using the rocker, and I'll do my best not to look for it ;^)

Boyd Ostroff March 20th, 2005 07:08 PM

Heh... you'll never notice it with the rocker because it's impossible to get a slow zoom with it ;-) If you want the slowest. smoothest zoom you pretty much have to use a controller with the PDX-10. So Tom has put his finger on the problem. I like to use the slowest possible zoom the camera supports and the controller makes that easy. But in doing so you go from nothing immediately to that speed as soon as you push the button.

I was just copying a tape I made with my VX-2000 three years ago, and realized how much nicer a system that camera has with its zoom ring. I never felt the need for a controller with it, and the slow zooms were generally a lot better.

I am not a fan of zooming in the least, but when shooting live performances you don't have much choice...

Tom Hardwick March 21st, 2005 02:17 AM

I know what you mean Boyd about 'not having much choice'. But the best bit about using a zoom controller is that you don't have to touch the camera at all, so removing any disasterous wobbles.

The latest zoom controllerss even allow you to switch the VX2000 between auto and manual focus, and operate the 'push auto' remotely as well. If you try and push that button on the side of the camera when you're in full tele position, it's asking for trouble.

tom.

Chris Long March 21st, 2005 02:32 PM

Thanks! That clears that up!

Chris

Sean McHenry April 28th, 2005 11:02 AM

As I get to edit all my footage in Avid, I always try to do any zooms coming out of another shot. This way I can disssolve to the zoom already in progress.

When I shoot a zoom I intentionally start wider or tighter than needed. That leaves me the room to dissolve into the zoom.

I am going for the Varizoom soon myself as they have dropped in price recently.

My latest plans include the Century WA adapter (with the zoom through), a varizoom rocker controller and a small Glidecam. Probably the 2000 series.

That ought to hold me through the summer.

Sean

Tom Hardwick April 28th, 2005 02:07 PM

If you do decide to go with a Stealth or a Rock, do try them on the very slowest zoom position. On a PDX10 and a VX2000 both Varizoom controllers made the cameras zoom in tiny little jerky steps when I tested them. They may well have altered the design on the latest models - and I do hope they have.

tom.

Sean McHenry May 10th, 2005 08:51 PM

Ordered one earlier this week. Should be in any day. I'll let you know what I find out.

Thanks Tom,

Sean


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