Best video explaining AF

[ctitanic]

This photographer does not shoot Canon but his explanation about AF totally applies to Canon and when I was watching the video I remembered about those who have reported issues with the Canon R7. I really believe that this video explains many of the scenarios and things that they are not doing correctly.

I’m not saying that some R7 may have problems…

 

[Only RF]

I purchased his NR reduction package. At one time I used his two step process sending files from LrC to PS to apply different noise levels for subject and background. Since masking was updated with LrC 11 and particularly LrC 12 I have not had the need for that process.

Interesting video. I had an R5 and currently have an R6II and R7. My approach. This is new technology and it is fantastic but I expect it to fail. That makes things a lot easier because I don't worry about what it should have done, I make it do what I want it to do. I don't waste any time on that.

After about a year with my R5 I decided to go back to the shutter button for both AF and Metering. This freed up another BBF and ties in with his compositional freedom segment. I also never engaged the joystick or LCD to move the AF point/s around. Too slow for me. My current set up. AF-ON = Single point AF and * = Zone AF.

Since this is Canon site I will call it eye detect. Be it one subject it can't find to focus on or there are two subjects and it picks the wrong one I will override eye detect. This example is for two subjects in the frame. It is locking on the eye of the subject on the left but I want the one on the right. I press the AF-ON which puts into Single point, physically move the camera and get the AF point on the subject I want. I then release the BBF, the eye snaps in and I recompose. I use the * which is mapped for zone AF for birds in flight but it also works for stills.

I call the method I use force focus or override. The last two paragraphs also tie in with his comment about "as long as it is in reasonable focus". If the camera I struggling to find the eye and I use the force focus method I don't care where the AF point/s land. It can be anywhere on the subject. I've even experimented on a post the bird is sitting on. As long as the subject is in reasonable focus the eye will snap in.

I've explained this a few times and some think when I'm using force focus I'm putting the single AF point on the subjects eye. I'm not because that again is far too slow. Anywhere on the body will do. Once in focus it's the systems job to find the eye, not mine. I paid a lot of money for that technology. That is why Zone AF works even for stills and is sometimes better than single point.

Interesting bits about distance. I was amazed when I focused on a bird on a pond and it was just a spec. It found the head. For that or BIF. If it can't find the eye it will find the head. If it can't find the head it will find the body. When the system thinks it can work with the eye then it will revert back to it. Also for BIF if eye detect struggles with AF I can repeatedly toggle a BFF as needed. I find it faster to press a button on and off rather than move my thumb to find a different button.

As a summary this new tech so different. With DSLR's you could focus on a rock or a person. It didn't know the difference. It was just the object you put the AF point in and focused on it. We called it the subject. Now we have objects with eyes. As he stated the system does not really know if it is a person or animal. It looks for the patterns and shapes it was trained to identify. Subjects now take on a new meaning to me. One thing I found. If you are shooting animals or people selecting the correct subject is really important. I was shooting people and then started with animals and forgot to switch. I thought I had broken my camera.

Any that was my progress through all of this. I had to forget about what I had learned about DSLR's and retrain myself to adapt to eye detect technology. I have read posts on other sites where are people were trying to make it work like their DSLR's. That will just add to a struggle IMO.

 

[Only RF]

One thing that did stump me for a while was the new Switching Tracked Subjects (STS) option. How does this work with Case numbers?

DSLR's have six Case numbers and I used them all. With ML Canon dropped Cases 5/6 and the AF Auto Switching menu. AF Switching was easy to figure out. Just put it in Zone AF, lock onto a static target and move the camera left and right. At a higher setting you could see the AF points reacting more quickly as they dropped and picked up new points across the frame.

Now with ML we have two parameters. Tracking Sensitivity (TS) and Accel/Decel. In 2009 when I got my 7D I set TS to -2 and have shot that way for the last 14 years. If a deer was walking and went behind a rock, which is a obstruction, the system would ignore it for a short period and wait for the original subject to appear before it refocused on the rock.

With eye detect that deer walks behind another deer it is still an obstruction, but now with an eye. I came across this video which is pretty good for wildlife overall.

At minute 9:50 he shows how the AF point goes off the subject TS prevents refocusing. With my DLSR's I relied of TS at -2 for BIF. If the AF point fell of the bird for a second it game me time to get it back on.

At minute 10:20 he shows what happens when the main subject goes behind another one. It appears because the obstruction has an eye STS will be used instead of TS.

That is how I understand. I'm always open to any other explanations.

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[ACEkin]

This photographer does not shoot Canon but his explanation about AF totally applies to Canon and when I was watching the video I remembered about those who have reported issues with the Canon R7. I really believe that this video explains many of the scenarios and things that they are not doing correctly.

I’m not saying that some R7 may have problems…

I don't use subject tracking mode as I do not generally photograph moving subjects. My two R7 kits indeed had strange problems, even when used on a tripod. The two new replacements are used in identical manners and the focus problems disappeared. As I explained in the article on my Web site, the salesperson in the store took two test shots, one with my lens and one with an identical lens he took off from the display. The difference was immediately visible, based on which he offered to replace them both. The advice offered in the video may be quite useful for those who use focus tracking though.