7D focus, what the heck.

You're shooting through trees, use single point OR spot, not expansion. I would singe single or spot most of the time anyways, i want to know exactly where im focusing and not have the camera pick. Expansion is great for BIF and some other things though.

Allan.L wrote in post #14244806
You're shooting through trees, use single point OR spot, not expansion. I would singe single or spot most of the time anyways, i want to know exactly where im focusing and not have the camera pick. Expansion is great for BIF and some other things though.

Well your right. In this situation I would have chose single point also, but that's not the question at hand, I don't think? If I was in a hurry and my camera was set to all of the focus points in the center square, and I aimed the camera at the squirl and the center focus point on his head lit up and the camera beeped. I would say I got a problem if his head is out of focus. Using a single focus point wouldn't be any different?

Hitthespot wrote in post #14244789
I don't understand all this talk about which focus point his camera is set to. I never have in these threads. Your camera will clearly show you which focus point it used ( at least mine does ), and if it is not focusing on that point you have a problem. I'm still guessing, he is back focusing, needs a camera adjustment, or has a problem between his camera and lens.

Yes it may show you the focus point square but the actual focus point sensor is a lot bigger than the square, so showing one square up that looks like it should be on target could be way off.

RobDickinson wrote in post #14244898
Yes it may show you the focus point square but the actual focus point sensor is a lot bigger than the square, so showing one square up that looks like it should be on target could be way off.

Again your are correct. In that case you would have two focus squares light up confirming focus. Anything within those two focus squares could be in focus, however when I'm in expansion I rarely if ever have two focus points hit focus. My camera almost always focuses on the center focus point if there is something there to use. If my camera lights up two focus squares then I expect something within both of those squares to be in focus. Also If the focus point is bigger than the single square you chose, your screwed anyway?

I made some assumptions. He said he pointed the camera directly at the squirl, so I'm assuming he had center point confirmation. His picture should have been in focus unless his target was unusually small in the focus square. You are correct that if the focus point is half covering his head and half covering the branches the camera may choose the wrong target. In that case the only sure thing is to move closer, get a longer lens, or try to use spot focusing.

Looking at the 1st shot, I would've used single point AF & AI Servo, maybe spot af, maybe not. You had plenty of light so I would have stopped down to f5.6 for a better chance of getting the little guy completely in focus. At f5.6 your SS would have still been like 1/1600, more than enough to freeze the squirrel. Having said that, your 7D & 70-200 should be capable of nailing that shot easily at f3.2 with your shot settings. I would definitely try mfa if you're consistently missing focus on shots like that.

heavily cropped 7D & 70-200 2.8 ai servo & center point:

200mm, f2.8, 1/320s, ISO 200

JersFocus wrote in post #14244318
I am using AF point expansion and was taking pictures of a close up squirrel (3 yards).. my aim was DEAD on the rodent and I took many photos yet it seems the bark is more in focus!

Should I be using spot or something, I dont understand why its off on so many.

I can post more but its crazy, in some the branches in top right are in focus more then squirrel??

Yupe, my 7D did that too when i have AF Expansion turn on around the center AF. I, too, had my center AF square dead on my subject but for some reason the 7D's AF likes to pick something different.

Hitthespot wrote in post #14244834
Well your right. In this situation I would have chose single point also, but that's not the question at hand, I don't think? If I was in a hurry and my camera was set to all of the focus points in the center square, and I aimed the camera at the squirl and the center focus point on his head lit up and the camera beeped. I would say I got a problem if his head is out of focus. Using a single focus point wouldn't be any different?

Well, you are right about the lit-up and beep but only if the user selected One Shot. When using AI Servo, which in this case makes sense because of the subject might move, the AF points don't lit up in the viewfinder.

I was using one shot, I went back and turn on the AF so I could see where they were. They are DEAD on the eyes in 1st pic posted. The first one doesnt have anything in front of the squirrel and it focused on the left tree trunk, so that is disheartening. The second one my spot is right on his nose, so it could have picked up the branch to the left, which fine.

I am not saying its a problem with the lens, but I did just get it today from a POTN user. So I dont know its history.

I think this is user error, that would be on par lol. I will do a chart test, but I think I should just use spot, unless the target is clear and the majority of screen.

I appreciate the input, regardless.

Since I have a 7D I'm going to follow this thread. Let us all know what your final conclusion is after a few days of testing.

Thanks

Here are some that hit a bit better through the trees, I really should have used spot with all the tiny branches messing with the AF. I gotta learn to use ai servo for everything, as well.

Those last ones don't look bad to me. That's a tough subject for a camera to pick the correct AF distance on.

Thing is for the first few the focus is behind the squirrel , so the camera hasnt picked up the foreground twigs its either back focusing or grabbed the main trunk or tail or something.

A proper focus test and some MA may be needed.

RobDickinson wrote in post #14245515
Thing is for the first few the focus is behind the squirrel , so the camera hasnt picked up the foreground twigs its either back focusing or grabbed the main trunk or tail or something.

A proper focus test and some MA may be needed.

It doesn't need a focus test, what's happening here is the classic problem with using AF expansion, you're letting the CAMERA decide which point IT likes (hence the focus on the branch behind the squirrel). AF expansion is 5 POINTS!!

Hitthespot wrote in post #14244834
Well your right. In this situation I would have chose single point also, but that's not the question at hand, I don't think? If I was in a hurry and my camera was set to all of the focus points in the center square, and I aimed the camera at the squirl and the center focus point on his head lit up and the camera beeped. I would say I got a problem if his head is out of focus. Using a single focus point wouldn't be any different?

In your first shot, the camera grabbed the contrasty branch behind it, which is to be expected because with AF expansion you are letting the camera choose between 5 points! Use single point or spot, simple as that. AF expansion is not meant for this type of shooting. If i remember correctly, with AF expansion the center of the cluster lights up when one of 5 of the points has locked, not the necessarily the center point (even though that's where the light looks to be coming from).

Either way, all is not lost, I hope you stumble upon another squirrel and get a chance to nail the shot!

JersFocus wrote in post #14245381
I was using one shot,

And you were shooting at f5.6 and around 190mm. That will give you a DoF of around 5cm. All you needed to do is sway backwards or forwards one inch between locking focus and taking the shot - that would produce the results you're getting.

A friend of mine used to have the same problem. She would compose the image, half-press the shutter for focus and then recompose! She refused to believe me until we went through it all slowly.

If there's any chance that my subject is going to move, or that I am going to move, then I'll always use AI Servo.

Allan.L wrote in post #14245670
It doesn't need a focus test, what's happening here is the classic problem with using AF expansion, you're letting the CAMERA decide which point IT likes (hence the focus on the branch behind the squirrel). AF expansion is 5 POINTS!!

No it isn't. It is one point for the initial lock. Only if there is no detail will it even contemplate using the other points. From Canon's own bumpf...

hollis_f wrote in post #14246251
No it isn't. It is one point for the initial lock. Only if there is no detail will it even contemplate using the other points. From Canon's own bumpf...

I have read that, and I was going to include that in my post. The problem with shooting with AF expansion in situations like this is that there is detail everywhere. From my real-world experience it does seem to *try* the center first and then if it finds something better it switches very quickly to an outer point ( in situations like shooting through branches or BIF against a really busy background).

The outer points are there to assist when an object is moving right? I'm wondering if the camera is not still while shooting a static subject it may switch even faster.

Either way, single point or spot focus Even then one has to realize that the AF zone is a bit bigger than the box itself for single point.