Iris/exposure Fluctuates!!!
 

Is this normal, or is it not? I shoot manual all the time with my XL2 & 20X lens, mostly in 24pn. Why do I still see a fluctuation in exposure when panning the camera or if someone might move slightly off frame or into frame? I notice it mostly if I'm pointed at a white wall. Also, the indicator when looking in the VF indicates it fluctuating. I don;t see anything on the lens itself to make sure exposure is maunual.

Have you left the White Balance and Gain dB on "A"? This will also cause the exposure to fluctuate during a pan, so it is better to leave the balance button locked or on 1 and the gain on 0 or -3dB. If you are not in Manual, but in AV or TV, try to also press the exposure lock prior to panning.

And have you checked to see that your shutter speed is locked down?

Everything is off A. Gain always set at 0, and I never use A setting for white ballance. I used a white ballance I had stored in position 3.

Tony, as far as shutter speed, I use 1/48 shutter speed especially when shooting 24pn. As far as locking it down, I've never noticed any setting where it can be locked down. Am i missing something? My view finder always indicates it staying on 1/48 while shooting.

Is there a setting for manual iris on the 20X lens? Bottom line it seems that the iris setting fluctuates as indicated in the viewfinder, bobbing back and forth as I'm panning the camera toward the white wall. Or is a manual iris setting only possible on the manual lens?

The indicator will always fluctuate in anything but auto which will always try to center it. If you frame things cinematically the indicator is useless as it indicates the exposure of the entire frame, not the subject you may be focusing on. So dont even look at the indicator.

What mode are you in? The some of the modes trump the manual settings...



ash =o)

I'm in "M" (manual) mode. I never really use AV or TV, etc... when shooting.

BTW, thanks for all your responses :)

Hopefully there's some answer to what I'm seeing.

My exact settings are the following: M mode, manual focus, manual White ballance, 1/48 shutter , 24pn frame rate & 0 gain.

Joseph,

Do you see these fluctuations in your NLE?

- Jesse

Filming outdoors where light intensity can change dramatically within seconds, working in MF mode - by adjusting both iris and shutter speeds - may sometimes take too much time to keep up with the rapidly changing light levels.

Some of my work is in MF mode, but I often prefer to work in AV mode (brought over from my years in still photography), as this gives me full and instant exposure control.

In AV mode, just one press of the exposure lock button provides a non-fluctuating exposure during a long pan between light and dark areas of the scene.

Pressing the exposure lock button also provides both the shutter and iris readings in the viewfinder, and the odd click of the +- EV dial helps provide added adjustments when you shoot directly towards the sun or a bright background.

thanls again for all responses. i will try seeing what i can acheive in AV mode.

Like you Tony, I also like shooting in Av mode. It lets me keep the iris wide open for minimum DOF when desired and I usually click the AE offset just enough to eliminate most zebras (within contrast limits of course). I find that the AE in zero offset is a bit on the 'hot' side exposure wise.

-gb-