I'm about to discuss a pet digital photographic peeve of mine, but I'll try to avoid turning [RANT MODE] up to [HIGH].
Back in the days when I used film cameras, I would make extensive use of the
hyperfocal distance, particularly in my landscape photography. Don't be put off by the name: it's perfectly legal (as Eric Morecambe used to say, "They can't touch you for it!"). It's a simple but very effective idea, which exploits a basic optical property of any lens, which is:
For any given combination of focal length and aperture, there is a distance -- the hyperfocal distance -- which, if the lens is focussed at that distance, has the unique property that everything from
half that distance to infinity will then be in acceptably sharp focus.
Useful, no? For example, the old "standard" lens for 35mm cameras had a focal length of 50mm. At f/16, the hyperfocal distance for that focal length is about 21 feet. Set the lens to f/16, focus it at 21 feet, and everything from 10.5 feet to infinity will be in acceptably sharp focus. Guaranteed! No need to focus on anything in particular.
To make this easy, lens barrels used to be engraved with "depth of field" marks, so that if, for example, you had a 50mm lens on the camera and were using an aperture of f/16, you would simply line up the "infinity" marking on the focus scale with the "f/16" marking on the "far away" side of the DOF scale.
Et voilĂ ! Hyperfocal distance set!
Naturally, there is some pedantic quibbling about that phrase "acceptably sharp". This involves the positively theological concept of an "acceptable circle of confusion", and there are some lovely equations you can do which
will deliver different hyperfocal distances depending on the value you supply for the circle of confusion, but this kind of focussing is always going to be an approximate business, and anyone seriously troubled by the size of their circles of confusion needs to start that search for a Life right away.
But that was then, and this is now.
Hyperfocal-ish... Don't know about infinity, but both
the near and the far fences are acceptably sharpDigital cameras are amazing things. The sheer brilliance of the programming that underlies their functionality is mind-blowing. I used to be a "manual only" kind of guy. I'd meter off the ground at my feet, make allowance for subject brightness and contrast, and -- more often than not -- set the camera at the hyperfocal distance for my chosen aperture. But now... Set a decent digital camera to "auto" and it beats my judgement 99 times out of 100, in a fraction of the time it takes me to say "Hmm, let me think..."
But. The one thing that virtually no digital camera has, and which every digital camera could really use, is a [HYPERFOCAL MODE]. It would be so easy! Assuming the camera's software knows the focal length and aperture currently in use, why on earth can't it do a moronic little hyperfocal calculation, and set the focus accordingly?
I keep re-reading camera manuals to see whether I've missed it or whether they've called it something cute like [FOCOMAT] or buried it in the "scene modes" somewhere, but no. I believe some Ricoh cameras do have this feature. Even the crude three settings for "zone focussing" that used to figure on ancient film cameras (flower! / people!! / mountain!!!) could be handy.
Perhaps there's a technical obstacle? My suspicion is that enabling the lens to be focussed at an actual pre-determined distance -- rather than reactively to whatever is detected by the camera's fancy focussing matrix -- may be too great an engineering problem to be worth tackling. If so, what a shame.
But I will send a free A4 print of the image of your choice to anyone anywhere in the world who can show me how this
can be done (by simple software settings) on any one of these cameras: Canon 45oD, Olympus E-P1, Panasonic LX3, Panasonic GF1!
Hyperfocal-ish... But,
no matter how great the DOF, nothing
will stop the wind blowing stuff out of focus...