Locking The AF Point for Super-Sharp Photos
This blog relates to a simple trick which many shooters arrive at through experience (or other people’s blogs!!) but if you’ve not discovered it, chances are you’re leaving some of your photographic results to, well, chance…. or at least to the whims of your camera’s auto-focus system. Whilst this may not be particularly relevant for those hardcore, strictly manual-focus freaky fighter-piloty sniper types out there, for those of us whose NHS glasses in primary school had thicker lenses than their textbooks, autofocus (and this technique) are indispensable in many shooting situations.
Modern digital cameras provide a range of AF points scattered across the frame and intuitive Auto-Focus functionality for fixing on and even tracking moving subjects, but even the smartest machine is still not sentient (thank God, have you seen Terminator?!), so most photographers prefer not to let the camera decide exactly what the picture’s subject should be, lest it get it wrong. This is especially relevant shooting portraiture, or in low light, where wide apertures mean shallow depth of field and a decreased margin of error on your focal point. Similarly, macro photography involves greatly compressed depth of field, so even a slight case of front or rear focussing can mean the focal point of an image (an insect on a flower or diamond on a ring) is missed. Whilst landscape photography generally involves narrow apertures and deep focus, there are still many potential planes of focus at very different relative depths. The human eye is extremely sophisticated and can usually spot where the sharpest focus occurs in an image, so let that be exactly where you want it, not where the camera decided it should have been. Each of the images below demonstrate just how many potential focus points there are in a range of images.
For setting this function on other brands of camera, check your instructions or Ask Jeeves (when he doesn’t know, use Google, like a normal person).
Whilst it may seem most intuitive to always lock onto the middle point, certain shooting situations benefit from choosing a point towards the edge of frame. When mounted on a tripod, the camera only affords a little wiggle room so you may want to lock a point closest to your model’s face when shooting fashion for example. Even if they step forward or back from their designated mark from time to time, your chosen AF point should remain closest to the intended point of focus, necessitating just the smallest of adjustments.
There you have it. A simple camera trick which you’ll find indispensable as soon as you begin to use it.
Lock, stock and several smoking shots! Have fun