View Full Version : Iris adjustment in Tv mode - does it "step"?


Stuart McKenna
September 7th, 2007, 03:55 PM
When you change the iris in manual mode, it is easily noticeable with the "step" up or down. When set in Tv mode (Shutter Priority) the camera automatically adjusts the iris as necessary as lighting changes, correct? And as it changes, is it noticable in "steps" (like when controlled manually) or does it do it smoothly?

Does anyone know if an XL1 "steps" too?

Does anyone know how it "decides" to change the iris? Is it center-priority, no over-exposure priority, best overal balance priority?

Does anyone have a video of a stage (dance preferably) while set in Tv mode? I'm thinking of using this for the wide camera which will not be manned.

Richard Hunter
September 7th, 2007, 07:06 PM
Hi Stuart. I'm not sure if Tv mode gives smoother stepping, but if the scene lighting changes it will definitely be obvious. (Apart from the iris setting, there is a certain response time before the adjustment is made.) The exposure is adjusted based on the average of the whole frame.

Actually, using auto mode might not give you the best results. When the stage lighting changes it is for effect, and using auto mode will negate this. Maybe you could test what happens if you set the exposure manually (to avoid too much blowout in the highlights) and just leave it like that?

Richard