Videoing

[muppetdave]

This will probably sound stupid, but I was watching something the other day, and the chap was recording in IMAX (not that I think that's relevant to the question), and he said, "setting the aperture at f4" - I'd never considered that in videography people set their aperture opening - I'd assumed it was a constant and then you move from wide to zoom and that was about it. Is there the same approach to the relationship between aperture and focal length when recording moving subjects in this matter? I guess there is as the front end is really the same as a camera, it's the image capturing device that is differing?

[Simpo Two]

Video cameras call it iris, but it's the same thing. Fordo will be able to tell you all about it.

[muppetdave]

Had just never really considered it!

[Fordo]

yup, aperture / iris just as important in the world of video / film, as it is with photography. Wouldn't be able to control depth of field without it!

Its shutter speed thats the variable that tends to stay the same. Generally you shoot at a shutter speed twice your frame rate- generally in the uk, that means a shutter speed of 1/50th- it give natural looking motion blur. anything faster gives a very stuttery, 'saving private ryan' look. Sometimes good in sport, if you want every frame looking crisp and sharp, but it comes at the expense of smooth looking motion.

In the film world, aperture is usually the first thing set. The director of photography will set the iris to get the depth of field and 'look' that he wants, then the actual exposure will be taken care of by ND filters and/or how the scene is lit.

Ive had my hands smacked, as a cam op, from touching the iris before.- on a film set, thats the dop's job

[muppetdave]

Interesting, thanks!