If you are on a mountain – and you’re photographing a mountain across the way – so that everything is 10 miles from you then focus isn’t much of an issue. Set yourself to infinity and rock at any aperture. Since the only thing in the shot IS at infinity – presto! – sharp image.
Now what if you have something in foreground – say a large downed tree-branch – and something in the background – say a waterfall like Cascade Falls at Matthiessen State Park. Then where do you focus to get it all in focus? Welcome my friends to the magic focus place known as the hyperfocal distance point.
Let’s take two options for focusing. First you’ll pick an aperture that assures you enough depth-of-field – even if it’s more then you might need. So race out to f/22 or higher. Now you could focus on the branch – ensuring it’s in focus – but that may throw your waterfall out to the soft side. You can focus on the waterfall – but yeah – depth-of-field doesn’t come as far forward as it does backward. The end result is you’ll probably have a very soft tree branch. Okay – well – the general rule of thumb for getting front-to-back focus is to go about 1/3 of the way in. Not bad, not bad at all. But what if I told you there was exactly one spot to focus so you could maximize your DOF? Would you want to focus there? OF COURSE you’d want to focus there – and that’s the hyperfocal distance point.
Who remembers their old film cameras? Just two of you? Well, let me get out my ‘ol Spotmatic F from Pentax, circa 1975. Let’s take a look at the lens barrel.
Alright – the little red box? The depth-of-field guide. Lensmakers for the big guns generally ignore this feature nowadays but it was pretty cool. The lens is set at f/8. I can instantly tell what’s going to be in focus because of the guide.
Let’s look closer:
At f/8, everything between the “8” symbols on my guide will be in focus. So if I park my infinity symbol squarely over one “8”, I find that with this particular lens (a 50mm) that everything from about 20 feet to infinity will be in focus. Picture two stops more open – f/4. You can see that the DOF is much narrower. The guide was a handy way to know what you could expect to be in focus.
Let’s jump ahead now to a simple explanation of what hyperfocal distance is. Simply put – when the camera is focused on the hyperfocal distance point – everything from 1/2 that distance out to infinity will be in focus. If the hyperfocal point is 10′, e.g., then everything from 5′ to infinity will be in sharp focus. That’s essentially what the old depth of field guides were telling you. Okay, simple enough – as long as you can figure out WHERE the hyperfocal point is. Let’s get to that, shall we?
Alright – now the semi-bad news… there’s math involved. Hyperfocal distance is unique to focal length of the lens and aperture. For example, a 100mm lens will have different hyperfocal distances then a 50mm lens. It’s also tied to something called – rudely – the Circle of Confusion. Yuck.
The semi-good news is you don’t have to do the math. Don Fleming, who runs DOF Master, has done all the work for you. First he has written an article so amazingly complete that I should have just linked to it like this. But if you don’t want amazingly complete just stick with me for another minute. Don has also given you numerous tools you can run online or download and print. And you can completely customize them for each lens you shoot with. He even has apps for the iPhone and Palm handheld systems.
Using these printouts, I can head out into the field and look at my piece of paper and instantly know that for my 18-200 lens at 20mm and f/5.6 that my hyperfocal distance is exactly 9′. So as long as my nearest object is at least 4.5′ away – I’m golden focusing at 9′. Everything from 4.5′ to infinity will be sharp. And at f/8, my hyperfocal distance drops to 6.5′, giving me everything from 3.25′ out to infinity in sharp focus. Excellent.
And even if the object looks fuzzy in the viewfinder, it will photograph sharp (you’re viewfinder is wide-open; hit your DOF preview button and watch it come into focus). Knowing your hyperfocal distance may let you shoot a little more wide open then f/22 as well – saving you some shutter speed for a handheld shot – and it will definitely tell you where to focus your camera. Good luck.