Picture dims when white enters

C

cgrosso74

Active member
I am on a shoot right now. We shot a scene where there is a unit in the shot and a wokman wearing a white protective suit enters the shot. when he enters, the darker parts of the frame go dim. The camera is acting as if it's in auto iris but it's not. Anyt ideas?
 
Interesting way to refer to it! Thanks for the fasat reply,a crew member here has said that he remembers the same problem with the PD-150.
 
Really everything is manual? Gain, Shutter, ... And you do not have cinema gamma and/or black strech on?
 
We're having the same issue with our Z1Us - it might well be a latitude thing within the way the imager balances high-contrast images. We routinely let the camera gather a quick averaging exposure and then switch over to manual control. All of our cameras are set to 85% zebra, 0/6/12 gain - though I have yet to use 6/12 in any instance.

Indoors, in available light, this camera is always below a 2.8 at 1/60. I regularly push closer to F2 - thankfully there are a couple of increments in between. If anyone can resolve the "automatic" compensation within the manually-locked iris, I'd love to know what the answer is!

I'd also add that the camera seems unable to or is very slow to find proper exposure between 65% and 90% in the zoom. At full zoom, the camera performs fine - gathering good exposure information. Auto focus falls apart within this same rough zoom range as well. We're usually shooting manual focus, but there have been times we've jumped over and been let down even in well-lit situations.

e
 
Make sure you have the shutter speed on manual control as well. The FX1/Z1 will use any and all methods it can find to auto-adjust exposure on you. If any of the controls are left auto, it will use them -- so you need to set iris, gain, and shutter all to manual control. I figure you know that already, but you didn't mention it specifically so I thought I'd just throw that in there...
 
We're going to look at this on Tuesday morning for all cameras. Shutter shows 1/60th in the VF, but I suppose it might well be changing on the fly and only indicating the set rate?

On gain, if the toggle is set to "L" (zero in our case) are you saying that the Z1U will electronically bump to M or H? If so, that's totally f-ed up.

Just to clarify, the center position on the switch under the tape door (next to IRIS, GAIN, SHUTTER, WHITE) is the one that allows manual control? This is where the cameras are set now.

Let's just say that we want shutter 1/60, manual iris using the dial and gain locked at 0. How do we achieve that with the camera making no changes? If I read the manual correctly, we adjust the camera in AUTO/MAN, then switch it over to LOCK? Effectively, the left position is all AUTO while the center position is a combination of AUTO and MANUAL - with AUTO taking place when you depress an associated button? Or is it the reverse, with the camera adjusting itself until you depress a button for a temporary manual "override".

This camera reminds me of the drone fighter plane that decides it's going to operate on its own - forcing a hot young force of pilots to do battle against it with old analog technology. Sounds like it would make a great summer flick! Oh, wait... they're already doing that.

Thanks,

e
 
overlandfilms said:
Just to clarify, the center position on the switch under the tape door (next to IRIS, GAIN, SHUTTER, WHITE) is the one that allows manual control? This is where the cameras are set now.
Click to expand...


That's it. If you press the buttons IRIS, GAIN, SHUTTER numbers in the screen show up. That meens, it's set to that amount. No need to switch to lock (otherwise you can't change it easily).
 
It's just a wild-ass guess, but it may be the camera's built-in (in other words, non-user controllable) auto-knee or DCC-type circuitry kicking in. And unfortunately as is typical with this level of camera, it's probably designed-in and can't be "turned off." Again, this is just a guess.
 
We've got all twelve cameras toggled to center position with manual shutter 1/60; iris and white balance. The only time the image changes now is when you set the iris with a wide lens and zoom in beyond what it is capable of (e.g., F1.8 at wide results in a F2.8 at full zoom).

Otherwise the naughty Z1Us are behaving themselves now. Thanks again.

e
 
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