I recently read about a great idea for a new slr innovation over at photographyblog.com. Zoltan Avra-Toth proposes an entirely new focus mode for modern SLRs. Frankly I am somewhat surprised no camera maker has thought of/implemented this before as it would be pretty easy to do from a technical point of view. Anyway, what he proposes is to have a focus mode that automatically focuses to the hyperfocal distance as the focal length of the lens changes.
Focusing a lens to it’s hyperfocal length is a very useful technique, used mainly by landscape and street photographers, but the lack of a distance scale on most modern SLR lenses makes it rather impractical to use, particularly with zooms (as the H.D. changes with the focal length). However, making the necessary calculations would be a trivial task for the camera’s on-board processing, and since the camera and lens “communicate” focal length and focus settings it could easily adjust the focus to hyperfocal dynamically as the focal length changed. In fact, adding this mode probably wouldn’t even need any hardware changes, it could likely be done with a firmware update!
Of course the hurdle would be practical implementation – in other words, how would you “set” this mode, and how would it “handle” the camera. E.g. when in normal af modes, the camera focuses when you 1/2 press the shutter button. In this new AF-H (autofocus-hyperfocal) mode, you definitely wouldn’t want that, as it would be refocussing every time you tried to take a shot. I think the easiest solution would simply be to add another position on the af selector switch for AF-H and have it decouple focus from the shutter button when you switched it on. This could also be done in a menu, without changing the hardware, but that could get confusing as people would forget they had it on and wonder why their camera wasn’t focusing when pressing the shutter button.
Anyway, I think it’s a fantastic idea that would appeal to a large set of pro & advanced ameture photographers. So if anyone out there from a camera company is reading this – bring it to your R&D team, and get it done!