One thing, which is always absolutely essential to nail in photography, is the focus. There are several approaches to focusing in landscape photography and in this article, I will pros and cons of MF, AF, and BBF.
Let us start by breaking down the false dichotomies we often see in many articles and videos. Neither MF (manual focus), AF (autofocus), nor BBF (back-button focus) is the better option relative to the others. You can use each of them in many overlapping situations without it really making a huge difference.
As you can see in the video above, I discuss all three ways of focusing and share further thoughts on focus. Be sure to check it out. It is also important to mention this article is seen from the perspective of a landscape photographer or similar disciplines like architecture or cityscape photography.
Manual Focus
Dependent on your camera and system you switch between MF and AF either on the lens or in the camera menu. MF is the mode where you need to turn the focus ring (often on the lens) to find focus. For this, you will rely very much on your eyesight and the resolution of the screen on your camera. Most cameras can enlarge what you see on the screen with about a factor of 10, which can help you find the precise focus. On top of that, many cameras have the option to automatically enlarge the screen as soon as you start turning the focus ring, which fastens the process. In theory, it should not take more than a few seconds to find focus, and once you have found focus you theoretically do not need to refocus before changing composition, aperture, or focal length.
I most often use manual focus when I know I am not going to change composition or aperture. It could be while I was photographing through a sunset without changing position or if I was collecting photos for a time blend.
Autofocus
When using AF it is important to choose your “focus area”. The focus area tells the camera where to focus. If you use a broad focus area, you cannot be sure the camera selects the most optimal point of focus in your scene. I personally almost always use the “flexible spot:L” option on my Sony a7R3 and manually set wherein the scene I want the camera to focus. The trick is to enlarge the focus area (just as the camera automatically does in MF) and then press the shutter button half-way down to focus. Focusing like this has the benefit of very precise autofocus, which I usually trust over my eyesight – especially in situations with dramatic weather where you are being pushed around. However, unless you switch to MF, you will refocus each time you hit the shutter button, which inevitably will change focus ever so slightly making stacking photos in post-processing a living hell.
Back-Button Focus
What if there were a way to get the precision from AF, but avoid the constant refocusing? The answer is "back-button focus". Enabling BBF moves the focus function from the shutter button to another button, which is likely on the backside of your camera (hence the name back-button focus). On my Sony camera, I use the AEL button, which is easy to hit with my thumb. Changing the focus function to BBF does require a little bit of getting used to, but after nine months of using it, it is my preferred way of focusing in 90% of my photography.
Whether I stay put in the same location for a longer time or I change my position and composition relatively often, it is easy and fast to refocus by enlarging the screen and hit the AEL button to get focus.
There are situations where MF is preferable to BBF. A couple of examples could be during snowfall or heavy fog. During snowfall, AF might lock focus on the foreground snow throwing your subject out of focus, and during fog, the camera might not even be able to find focus due to the very flat scene. In situations like these, you will have to help the camera and focus manually.
When I handhold my camera and photograph through the viewfinder it can often feel a bit clumsy to use MF or BBF where you need to find the AEL button when you want to focus. In that case, I prefer to use regular AF and have the shutter button as your focus button too.
One of the final photos from the video above.
Check out the video above. In the video, I discuss focus peaking for manual focus and where to put your point of focus. Also, let me know how you usually focus in the comment section below?
Manual focus for me is quite difficult because of my eyesight (damage top optic nerve) but anyone wearing glasses could run into problems...the lens cut may not be uniform, the frame might not be stable so it is farther or closer to the focal point of the eye than it should be, smudges on the lens, etc.
Not trying to take away from your article but I sure miss the split image focus rings older SLRs had.
Doesn't your camera offer a DoF scale?
Actually I was very surprised he didn't even mention it.
Opposite to the scales on lenses and many acclaimed phone apps, I found the DoF in my Fuji camera is rather accurate when considering CoC. For the phone apps, I had to hand-tune them, even when the especific camera model was provided.
Now if you aim at very short DoF, I would suggest just digital zoom in and then use AF. I found split screen simulation in my camera a bit cumbersome.
If it does, I don't know about it.
Have you tried magnify AF I mention, Chaz? :) That could solve the issue. I trust it very much.
I haven't found that yet on my camera (Nikon D810).
You'd have to be in Live View. Then, you can magnify with + and - button on the left. Use your dial pad to move the focus point around.
It took me some time to figure out where everything was and how to use the process. From the little I've seen so far, it looks like a tripod would simplify things but as most of my photography involves moving subjects I may have to try it with landscapes. Thanks a lot for getting me on track.
I totally get changing the focusing method based on the setting. I manually focus assisted by zooming on my back screen more these days, when I'm on a tripod. But I don't know how you switch between back button focus and the traditional shutter button focus. My brain wouldn't be able to keep up with that change. I switched to BBF years ago and I can't go back.
Sony users can have the best of both worlds with the AF/MF control hold button. I find this works super well for landscape photography. I keep my lenses set to AF, the camera on MF, and my back button to AF/MF control hold. In this configuration I can turn the focus ring at any time to MF, if I push the back button I get AF. This way I never need to switch focus modes or play with lens switches. Then I also have some custom modes on C-AF that return the AF to the half press shutter button for wildlife/oh $#!t moments
Why this? Can't you override the AF by just turning the focus ring on the lens? Along with back button focus you only need to change the AF mode (single or continous) or the AF area.
In DMF mode, yes. In AF mode, no. Unless I'm missing something :-)
Thank you. Had to search for that (I am no Sony but Nikon user). How complicated! With Nikons and AF-S lenses (older AF-D lenses have a screw driven AF) you can override the AF at any time without the need to flip a switch.
Excellent video Mads. I have copied your technique over half year ago with the video of FOCUS. Great Job.
Given that it's sort of a no-brainer to use AF for sports photography and family picnics, that leaves the other kind of photography where you're not really in a hurry. So, who cares which button you use?
Great video, Mads! You created an excellent mix of scene setting, narration, and the lessons with the results. And you did it in just a few minutes.