EX3 - Dark Images

[Steve Blackwell]

Hi, been using the EX3 for some time now, but never quite got around this problem....

The auto iris tends to leave images a bit dark. We always have to go manual and open it up a couple of stops. Even going into the menu and utilising the +1 stop setting to let in more light doesn't seem to make it much brighter.

I know its best practice to do it all manually, but sometimes we need to use auto iris for operational reasons.

Has anybody else had the same problem and did they find a remedy? TIA.

[Hirata Tomoki]

Its happen for me same, are you use Cin2 on PP?

[Chad Johnson]

Never use auto iris. If you point it into the sky, or a bright area, it will make a dark image. Also with auto, your exposure is always changing, which makes for very amateur looking footage. You need a constant exposure to properly color grade in post. There is no legitimate reason to shoot auto. Just manually expose for the subject, and let the rest do what it will. You will always get the same results in auto.

[Kevin Spahr]

I too have committed the "un-pardenable sin" of using auto iris. But my EX3 auto iris does a good job and I have been quite happy with the results. I have not noticed the problem you mentioned.

Just speculating here, but what if you focused on a gray card, manually set the level for it, and turned the auto iris on to evaluate the actual exposure changes rather than using a scene?

Then again, I usually shoot things adjusted down a stop or so below where it could be as a matter of personal taste.

I do find it hard to make adjusts to the iris when the camera is on the end of a jib 12' away.

[Sverker Hahn]

Use zebra to get correct exposure. The aim is to get the shot as bright as possible without getting the brightest parts blown out. You may use only zebra 2, which is always 100%. So if you set you exposure so that zebra 2 just disappears, you are quite good.

I also use the histogram in the viewfinder to get a good exposure.

[David Issko]

Originally Posted by Steve Blackwell

but sometimes we need to use auto iris for operational reasons.
TIA.

With all due respect Steve, might I ask, and I am asking in a serious manner, what operational reasons cause you to use auto iris?

[Buck Forester]

For me I will use auto iris if I'm in conditions where the light changes dramatically and quickly and often and it's all one take... like in a forest going from shade to light to shade to light... or if a shot is really bright when wide and zoom in to a dark area... I can't change the iris on the fly as smoothly as the auto iris does for me. I've had no problems with auto iris looking unprofessional in the conditions I choose to use it.

If you're going from a dark scene to a bright horizon, especially when there are other things in the composition (people, trees, etc.) then you can't use auto iris because the darkening transition is not subtle, but if you're running/moving with the camera in changing light conditions it's usually quite subtle and better than one can do manually while composing and running. At least that's been my experience. If someone has a method of doing it better, I'd be all over it. I just don't see how you can manually focus, manually change iris, keep composition while moving fast in light that keeps changing.

[Buck Forester]

It might be your EX3 because my EX1 does not shoot dark in auto iris.

[Vincent Oliver]

Check your EV value is not set to -1 or other, Click on the aperture setting in the viewfinder to open up the EV values.

I never use Auto Iris on the EX3 although I do use a lot of Auto settings on the Canon XHA1 (mainly for wedding work when shooting scenes quickly)

[Walter Brokx]

Originally Posted by David Issko

With all due respect Steve, might I ask, and I am asking in a serious manner, what operational reasons cause you to use auto iris?

In the cases your left hand is not availble and moving your right hand away from the grip will cause unhappy accidents.
;-)

[Steve Blackwell]

Thanks very much for your help guys, I'm very grateful that so many of you have put in your thoughts... back a couple of

Originally Posted by Hirata Tomoki

Its happen for me same, are you use Cin2 on PP?

I think so Hirata, I'm using PP5 which says "Cine" and the Gamma is set to STD3.

Originally Posted by Kevin Spahr

.....Just speculating here, but what if you focused on a gray card, manually set the level for it, and turned the auto iris on to evaluate the actual exposure changes rather than using a scene? .

Tired that Kevin, thanks. I manually set it to what I thought looked good, but the shot went darker when I turned on the auto.

Originally Posted by Sverker Hahn

Use zebra to get correct exposure. The aim is to get the shot as bright as possible without getting the brightest parts blown out. You may use only zebra 2, which is always 100%. So if you set you exposure so that zebra 2 just disappears, you are quite good.

I also use the histogram in the viewfinder to get a good exposure.

Zebra was set to 1 at 70%. I use Zebra when manually setting up a shot - but again, like with my reply to Kevin, switching back to auto and the scene goes a bit darker. I shall change the Zebra to 2 and 100% and see what the difference is.

Originally Posted by Vincent Oliver

Check your EV value is not set to -1 or other, Click on the aperture setting in the viewfinder to open up the EV values.

Thanks Vincent, do you mean the TLCS > Level ? Thats set to 0.

Originally Posted by David Issko

With all due respect Steve, might I ask, and I am asking in a serious manner, what operational reasons cause you to use auto iris?

Walter is kind of right David - creative jobs are fine, but some "operational" jobs move at extreme pace and the lighting conditions vary considerably (lit rooms, dark hallways). And your "free" hand is sometimes carrying a riot shield.

[Sverker Hahn]

Originally Posted by Steve Blackwell

Zebra was set to 1 at 70%. I use Zebra when manually setting up a shot - but again, like with my reply to Kevin, switching back to auto and the scene goes a bit darker. I shall change the Zebra to 2 and 100% and see what the difference is.

People say that zebra 1 at 70% gives you a good exposure of skin. You should see zebra on faces if you use it. When using zebra 2 you should not see any zebra at all. Quite different way to work, in other words.

[Walter Brokx]

Originally Posted by Sverker Hahn

People say that zebra 1 at 70% gives you a good exposure of skin. You should see zebra on faces if you use it. When using zebra 2 you should not see any zebra at all. Quite different way to work, in other words.

Using 70% zebra to expose like it's 100% zebra will give you really underexposed images.
100% warns you for blownout highlights.