Sony HVR-Z1U picture problem at DVinfo.net

Jonathan Holm · March 1st, 2005, 12:13 PM

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.

Ignacio Rodriguez · March 1st, 2005, 12:34 PM

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.

Barry Green · March 1st, 2005, 12:56 PM

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.

Jonathan Holm · March 1st, 2005, 01:17 PM

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.

Sean M Lee · March 1st, 2005, 01:24 PM

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

Ignacio Rodriguez · March 1st, 2005, 01:35 PM

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

Mike Tiffee · March 1st, 2005, 01:40 PM

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

Derek Serra · March 1st, 2005, 02:39 PM

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.

Ignacio Rodriguez · March 2nd, 2005, 06:51 AM

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.

R Geoff Baker · March 2nd, 2005, 07:47 AM

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

March 1st, 2005, 12:13 PM	#1
Jonathan Holm New Boot Join Date: Feb 2005 Location: Pasadena, CA Posts: 6	Sony HVR-Z1U picture problem 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.

March 1st, 2005, 12:34 PM	#2
Ignacio Rodriguez Contributor Join Date: Sep 2003 Location: Santiago, Chile Posts: 932	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. __________________ Ignacio Rodríguez in the third world. @micronauta on Twitter. Main hardware: brain, eyes, hands.

March 1st, 2005, 01:35 PM	#6
Ignacio Rodriguez Contributor Join Date: Sep 2003 Location: Santiago, Chile Posts: 932	Jonathan, can you describe whether it was a subtle thing or a dramatic change in exposure? __________________ Ignacio Rodríguez in the third world. @micronauta on Twitter. Main hardware: brain, eyes, hands.

March 1st, 2005, 02:39 PM	#8
Derek Serra Regular Crew Join Date: Feb 2005 Location: Cape Town, South Africa Posts: 76	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. __________________ Derek Antonio Serra Indie Filmmaker www.indv.co.za

March 2nd, 2005, 06:51 AM	#9
Ignacio Rodriguez Contributor Join Date: Sep 2003 Location: Santiago, Chile Posts: 932	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. __________________ Ignacio Rodríguez in the third world. @micronauta on Twitter. Main hardware: brain, eyes, hands.

March 1st, 2005, 12:56 PM	#3
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	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.

March 1st, 2005, 01:17 PM	#4
Jonathan Holm New Boot Join Date: Feb 2005 Location: Pasadena, CA Posts: 6	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.

March 1st, 2005, 01:24 PM	#5
Sean M Lee Regular Crew Join Date: Feb 2005 Location: Indy Posts: 160	those buttons are easily pushed, so you may have sent one back to auto and not known it.

March 1st, 2005, 01:40 PM	#7
Mike Tiffee Regular Crew Join Date: Oct 2004 Posts: 150	Yeah, sounds like something was in auto- maybe shutter? The camera won't budge in full manual mode.

March 2nd, 2005, 07:47 AM	#10
R Geoff Baker Major Player Join Date: Jan 2005 Location: Ottawa, ON Posts: 471	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