Today I was doing a test zooming in with manual IRIS at 2.4 or OPEN, and when lens was full tele the camera automatically adjusted the IRIS to 2.8
Could anyone explain that please ?
It's the way the lens works. All cameras in this price range do the same thing... The FX1 has it marked on its lens as f/1.6-2.8, the Canon XL2 is f/1.6-3.4. The more zoomed-in you are, the smaller the maximum aperture can be.
If you want to maintain a constant aperture throughout the entire zoom range, you'd have to set your aperture to whatever it is at the longest telephoto setting. In the case of the DVX, that'd be f/2.8.
