How to Lock Your Lens's Focus

KristinaW

Well-Known Member
  • #1
Locking Focus

Early on, you'll find that your camera can be very annoying in one respect, depending on how it's set. Let's say you get situated in a scene and push your shutter button half way down to use your camera's autofocus feature to focus on a subject that's dead center. Then, because you want to get a bit creative, you decide to point your camera slightly to the right or to the left, just to move the primary subject over a hair, so it's not so centered. You push your shutter button again and bam, you lose your focus. Because your subject wasn't dead center anymore, your autofocus decided to focus on what was. Having this happen over and over again can get tiring. Trust me. I've done it more than I care to admit.

How do you fix your focus so your subject will remain sharp no matter where you point your lens? That's easy. I'll explain down below.

If you turn your DSLR or mirrorless camera on and visit your focus settings, you'll find that there are two very broad areas of concern. You may have more then two settings, but there should only be two concepts. You'll see something called Single Shot or One Shot and Continuous. To keep your focus on your subject like I described above, make sure you've got Single Shot selected. Then, when you focus on your subject by pressing your shutter button down half way, don't let go of it. If you do this, your focus will be locked in no matter where you point your camera. For something like the example above, all you'd need to do is point your lens slightly to the left or the right and then continue pressing the shutter button to take the photo.

I will tell you that there's another, more advanced, method for locking focus. It's called Back Button Focus and it's the subject of another post. It's a great way to focus your lens on something and then have the option of letting go of all buttons while the focus remains on the focal plane, with no additional work from you. To set this up, it takes a change in camera settings. If you want to know how to do this before I write that other post, please let me know and I'll fill you in down below.

To get used to locking your focus, you'll need to practice. I encourage you to familiarize yourself with your camera's autofocus settings and then practice focusing on something and locking that focus in. Then move the camera so the object is off to the side. You'll find that the technique makes for some well positioned objects in your photos.

Minimum Focusing Distance

No matter where you focus, you'll need to maintain what's called a minimum focusing distance. You'll hear this phrase around the photography world from time to time, but you'll experience what it means much more frequently. You know what I'm talking about - you get real close to something and try to focus on it and your camera does nothing more than give you a silent red square in the center of your viewfinder or LCD screen. It's frustrating, to be sure. As you back up away from your subject, you'll notice that you'll be able to focus. Different lenses have different minimum focusing distances. I've got a 24mm prime lens that can focus as close as something like 13". I've also got a 50-200mm zoom lens that can't focus on anything unless you're something like five feet away from it. Every so often I head out with the zoom lens and want to take a picture of an object that's very close to me. Again and again, I need to back up so I can capture the scene. What's the point? Be sure to think about what you'll be photographing before you leave the house and bring the lens or lenses that will cater to those things. A good all around lens is Canon's kit 18-135mm. The reason it's a kit lens is because it's so versatile and usable in so many different types of situations.

Here's a challenge for you: since you'll need to familiarize yourself with your lens' minimum focusing distances to avoid future aggravation, take each lens you own and get used to those minimum distances. You can look at the specs of the lens before you head out, just to familiarize yourself with what to expect. As an example, that Canon 24mm pancake lens I just mentioned above, it's actually got a minimum focusing distance of .5 feet, or six inches. Incredible.

It's All in the Eyes

The true test of an expert photographer is whether or not he or she can maintain focus on a model's eyes. We all know that if a person or animal is the primary subject of a scene, the eyes need to be center stage. If the model is completely still and will stay that way, it's fine to use your lens's manual focus, but if they're moving slightly, it's good practice to use your camera's autofocus. It's faster and can be more accurate at times. So here's your challenge: choose a model, preferably a human who knows how to behave. Sit them down and give their face good lighting. Use a tripod if you wish. Set your shot up and be sure to focus on your model's eyes. Be sure they're tack sharp. Once you have them the way you want, pan the camera so your subject is off to the side. Then, take your shot. Keep practicing by panning in different directions. This type of thing takes some getting use to, so keep going. When you think you've really got it, enlarge your lens's aperture so your depth of field is more shallow. When it is, practice some more. You'll find that you can make an ordinary scene with a person sitting in the middle of it a creative and interesting scene that's got a shallow depth of field, tack sharp eyes, and a model who's off to the side. If you decide to take on this challenge, be sure to post your photos down below for review. I'd love to see them. Also, let me know if you need any help or advice. I'd love to help. Thanks!
 
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