How do you set infinity on a lens? Does that mean your focus would take everything in? I've noticed the infinity sign on some lenses, but do you set it when you turn to zoom or the focus?
you might want to search for 'hyperfocal distance'
it's a calculatable figure to determine how to acheive maximum DOF based on focal length, aperture, and ISO i think.
basically at that focus point - everything from X distance to infinty will be in focus, where X is the calculatable figure based on the above criteria. i may not be exactly correct, but it's worth looking into.
You're kind of right, ISO has nothing to do with the equation. Also, where X represents the focal point, everything from Y (or much before X) to infinity, will be in acceptable focus.
No problem. I think the circle of confusion comes in to play, and in that case, sensor size and film speed / ISO may have some effect or another, but for some strange reason, I find the circle of confusion rather confusing...I never paid much attention to any of that while using infinity focus, and I never have a problem getting everything in focus.
Whereever you focus, the entire focus area is about 1/3 in front of the focus point and 2/3 behind. The depth of this in-focus area depends on the settings.
If you want everything in focus use a small aperture (say f22) and focus about 1/3 of the way into the scene.
