Students often ask me “Is it cheating to use AF?”
And I’m here to promise that it’s definitely not cheating – it’s what we all do.. most of the time!
Auto Focus is awesome…I honestly don’t know how photographers managed without it for all those generations! It’s fast and accurate, and if you’re choosing your own focus points you can pretty much be assured you nailed it. You don’t need to stop and check every shot on your LCD!
All that said, manual focus is not obsolete. But why would we bother with manual focus when auto focus is so…excellent!? Well, there are times when your auto focus system simply can’t lock focus, or can’t focus on what you want it to, due to a variety of different scenarios.
Firstly, let’s assume you’ve never manually focussed. Simply…
Don’t be discouraged if it takes a few attempts… particularly when shooting with very shallow apertures it can be hard to tell if you’re sharply focussed on your subject until after the fact.
When you want to get as much in focus from back to front as possible, set your lens to manual focus, turn the focus ring until it’s on the infinity symbol. Set your aperture to its minimum, which typically would be anything from f16 to f22 depending on your lens. Then frame your image and take the shot.
When set to infinity, your lens’ “Hyper Focal Distance” will determine a focus point that will achieve the greatest acceptable sharpness from near your lens to infinity. The range of acceptable focus achieved is dependent on your lens, your chosen aperture, your focal length, and the physical area you are framing.
Low light can be an issue in this situation, where the auto focus has difficulty locking focus, in which case you might need to use manual focus.
However you may always want everything in focus from back to front, in which case shooting at infinity on manual is the way to go.
You know those gorgeous backlit shots taken during the golden hours, when you have a golden halo of light surrounding your subject, light coming in from the side, and some haze you want to include? Frequently, AF struggles to focus in this situation, and manual focus is the only option.
You can try to hold your hand up to block the light so you can focus initially, and go from there.. but if your camera is still struggling then definitely try MF.
If you’ve ever attempted macro photography you’ll understand auto focus frequently has trouble locking focus even when you’re manually selecting your focus point.
What’s more, the depth of field is so narrow you want to have complete control over the sharpest area of the image.
If you’re not manually selecting your focus point, it’s very difficult to control what the lens locks focus on.
Ever taken a shot like this? It can be very difficult to focus on fine blades of grass or similarly delicate objects.
Not just because they’re small either, the sheer volume makes it tricky for the AF system to settle somewhere and lock.
This is, once again, another scenario when manual focus is faster than auto focus.
Related: Master your AF Focus Points