Recently picked up the Sony HVR-Z1U and ran some tests with it. We did one test where we zoomed the camera into a lighter part of a wall, then panned over to a darker part. Apparently, the camera compensated for this difference in light and automatically adjusted the light setting. We went through all sorts of different settings (F-stop, gain, white balance) and weren't able to turn that function off. Does anybody know if this is an automatic function of the camera, or if we can turn it off? Thanks.

I have observed something similar with my PDX10, even when in full auto and everything locked, I could tell --by changes in the zebra pattern-- that some kind of AGC was in place-- but it was quite slight.

I would not call it a "picture problem" though. I would think it is more of a control problem. Something in there is out of control.

That's a common question from brand-new FX1/Z1 users. The answer is, you have to make sure that all functions are in manual mode. There are a row of buttons along the bottom of the camera that determine automatic or manual control of iris, shutter speed, and gain. If any of those are in "automatic", the camera will do exactly what you describe. You have to set them all to manual mode, and then you will have full manual control.

It's not an image problem at all, it's the way the camera works.

I'm pretty sure we tried setting everything to manual and it still compensated for the change in light. We tried so many different settings that i feel like it's an automatic function of the camera.

those buttons are easily pushed, so you may have sent one back to auto and not known it.

Jonathan, can you describe whether it was a subtle thing or a dramatic change in exposure?

Yeah, sounds like something was in auto- maybe shutter? The camera won't budge in full manual mode.

The lens on the Z1 has a "variable" maximum F-stop of F1.6 - F2.2 if I remember correctly, depending on what focal length the lens is at. So if you zoom, at some point the lens will automatically adjust from F1.6 to F 2.2 before it reaches maximum telephoto. THis has to do with the construction of these fixed zoom lenses, and is apparently not unique to Sony.

I see your point Derek and I have seen that effect with many cameras, but Jonathan said this change in exposure happened when panning, not while zooming.

My guess is the gain was not locked -- an easy one to overlook. The PD-150 was designed the same way -- you need to lock the shutter, the aperture & the gain to prevent the camera from making any exposure adjustment.

GB