Interesting information. I’ve always used the small spot and placed it on the eye of my subject. Will try the larger spot when I shoot tonight.
I agree with MarshallG on this. I think people got hung up on Spot AF early on with the release of the R5 because some pro photographers who used it were able to keep the AF on a birds eye when it was in flight so they just transferred that to mirrorless camera system in the their videos. I could never do that. I'm sure others here can.
Spot focus covers a smaller area thus you get less contrast to work with and AF is all about contrast. Canon recommends not to use Spot AF on moving subjects. You will not get sharper images when shooting on a "flat plane" using Spot Focus compared to single point, expansion or zone AF. Spot AF is a specialized mode. If you are shooting the curvature of an eyeball it is a great tool. I have used it when shooting a perched bird through dense leaves and single point AF is picking up the leaves instead of the bird.
This paragraph is from a well respected Canon technical advisor. Link is below.
“Precise” is not the same as “accurate!”
We’ve said several times in this article that the Spot AF option does let you focus on a smaller area of your subject. In doing so, it does allow you to place focus with more care and precision — at least in some instances — than standard, Single-point AF would. But it’s vital for Canon EOS users to understand that Spot AF is not inherently more “accurate” than normal Single-point AF would be. If you set up a test, photographing a flat chart or wall with a tripod-mounted camera shooting squarely into it, you’d get equivalent results in terms of focus “accuracy” in test shots taken with Spot AF vs. the larger Single-point AF. So if you simply switch to Spot AF for all your shooting and expect that you’ll get a higher percentage of sharp images, you’re going to be disappointed.
https://web.archive.org/web/2018032...m/resources/articles/2014/spot_AF.shtml#page2
That being said sometimes Spot can be useful for normal shooting like if your subject is far away and the face is small. The outer areas of Single Point is wider than the face it could pick up foliage, etc behind the subject.
Use Spot if it works for you but don't exclude Single Point or other modes which provides more contrast for initial AF and tracking. You will figure out what works best for you.
Moving on only using Single Point or Spot is really defeating what mirrorless systems are about. Now that you are confident your camera works properly (from your other thread) you may one day want to explore what it can do for you.
The whole thing is all about the eye. These systems are relatively new and are just complex algorithms (AI) trying to figure out what you want to do. As they keep training the systems in then years we won't be having these conversations.
It takes a bit of getting used to withe the new Subject tracking and Eye AF. It doesn't always find your subject and can be frustrating. The key to it is when it can't focus on your subject you help it by using Single, Spot, Expansion or Zone AF as a pre focus technique.
I'm back to old school and use the shutter button for shooting. My camera is set to subject tracking and eye focus. Make sure you are on animals for animals, etc. That makes a big difference. The AF-On is set to Zone AF (for birds in flight) and the * button is set to Single point AF for static objects. There are many ways to program the camera.
Example. If I'm shooting a perched bird and the camera cannot AF I press the * button and any anywhere on the body will do. Once the bird is in focus I go back to the shutter and the eye or face snaps in. Watch this video between minutes 2 and 6. it is a Canon vs Sony shootout but see how the author uses expansion AF to pre-focus on his subjects when the camera isn't doing what he wants.
So as your learning curve gets less steep you may want to try that out. Being able to track your subjects eye is pretty wonderful.
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FP
