auto iris too dark
by dan jones
on
Nov 8, 2009 at 12:33:26 pm
I've shot a few things with my new EX-3 with no external monitor and all the footage has turned out too dark. Not unusably dark, but definitely under exposed.
I have been using the auto iris as a reference and then opening up from 1/2 to a full stop, and still it needs to be bumped up in post. This has all been at 1080p.
Re: auto iris too dark by Daniel Startek on Nov 8, 2009 at 2:01:17 pm
You should experiment with the Picture Profiles. Use a waveform monitor and a DSC chart. I find that Cinegamma 1 requires 1 extra stop or more over the auto iris (Cinegamma 3 + 1/2 stop) but other settings also affect proper exposure. I used to use just the zebra in the field but find the histogram is also valuable.
Re: auto iris too dark by Greg Ondera on Nov 8, 2009 at 2:47:54 pm
Auto iris is at least not the end of the world if it is dark. I often use it as I have to in surgery, because I can't often reach the cameras which are on boom arms. I certainly don't do this when I can have full control of the camera. And if I shoot an open wound case, in which auto iris will flutter and adjust when white surgical gloves come into the scene, I will most certainly use manual iris.
If the footage is dark then take it into FCP and use the 3-way color corrector to raise the exposure level as you would in photoshop. What is unforgiving about digital exposure is when you shot overexposed. And in principle, only underexposed footage can be brightened, but overexposed cannot.
Re: auto iris too dark by Rafael Amador on Nov 8, 2009 at 3:26:39 pm
I absolutely agree with Olof. Learn to use all the controls in manual.
However as Greg points, in certain occasions you need to use the Auto.
I haven't got with me the camera, neither the manual, but I think in the "TLCS"> Levels, you can adjust the iris increasing or decreasing the aperture in a fixed amount.
I haven't tried it.
Rafael
Hi Dan
FWIW everyone's focused on the iris, but have you done a camera monitor calibration test to make sure what you see in the monitor is what you're rolling to tape/drive/card. I've had guys turn their monitors up brighter and think they're exposed properly. NOT! It may have been bumped up accidently or not set properly from factory. Just a thought.
Hope this helps and best of luck.
Kind Regards,
Chris K.
Re: auto iris too dark by Noah Kadner on Nov 9, 2009 at 2:54:41 pm
Yeah I'd sit down and calibrate the onboard monitor at least- that + an auto iris check should be more than enough to get you into the ballpark of a usable exposure.
Re: auto iris too dark by Brent Dunn on Nov 9, 2009 at 8:13:48 pm
What also matters is your location lighting. Do you have your ND filter on, Gain off? If it is a low light situation, then maybe these bumps need to be made.
I just shot an outdoor event at sunset on the beach where I had one EX 1 unmanned. I had to leave it at autoiris, which saved my butt. Once that sun started dropping, it went dark fast. The lowlight capability of the EX 1 /3 saved the day again.
Brent Dunn
Owner / Director / Editor
DunnRight Video.com
