Inconsistent Auto-Focus Accuracy: Is it me?

First of all, I'm sorry for yet another one of "these threads." However, I think my pictures justify its existence. All of the other topics I have made thus far have been solved by the wonderful members of this forum, and I'm hoping the same luck will apply with this latest hiccup.

Anyway, on with the thread:

My Equipment: 60D, 70-300 IS USM. No filter was attached.
My Software: Canon Digital Photo Professional. (It comes standard with almost all of their cameras.)
Note: All of my pictures were taken straight from this software. I have not edited these at all.

First example of missed focus:

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Second example of missed focus:

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Here's where things get really strange. The lens *is capable* of great results. Here's the proof:

First Example of Accurate Focus

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Second Example of Accurate Focus

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NO camera will give you 100% accuracy. you'd be lucky to get 75% hit rate, especially on long focal length....

You think people that posts in the sample thread the only shot they've taken? Mate it's normally a case of one out of 10 shots if lucky...

kin2son wrote in post #14754909
NO camera will give you 100% accuracy. you'd be lucky to get 75% hit rate, especially on long focal length....

You think people that posts in the sample thread the only shot they've taken? Mate it's normally a case of one out of 10 shots if lucky...

Given that I'm a noob, I may not know much about AF accuracy. However, one thing is for certain: 1 of 10 is abysmal.

These are exactly the problems I had with my EF 70-300mm f/4-5.6 IS USM when I had a UV filter on it. Is there a filter on your lens? Once I took it off, the lens showed how good it could be. The only other blur issues I've had with it is when shooting under high current power lines that the IS vibrates and must be turned off.

I may be able to be of some assistance here

Do you have focus search on in the AF menu? If you do, try turning it off and see if that helps. On longer reach lenses this can make a pronominal difference, trust me (especially in AI servo).

macroimage wrote in post #14755006
These are exactly the problems I had with my EF 70-300mm f/4-5.6 IS USM when I had a UV filter on it. Is there a filter on your lens? Once I took it off, the lens showed how good it could be. The only other blur issues I've had with it is when shooting under high current power lines that the IS vibrates and must be turned off.

No filters at all. (I've amended my original post to reflect this.)

Andrew Tingle wrote in post #14755024
I may be able to be of some assistance here

Do you have focus search on in the AF menu? If you do, try turning it off and see if that helps. On longer reach lenses this can make a pronominal difference, trust me (especially in AI servo).

It is turned *on.*
I thought this was a good thing. Maybe it isn't....

Could you please explain further?

TheRightLight wrote in post #14755114
It is turned *on.*
I thought this was a good thing. Maybe it isn't....

Could you please explain further?

Of course, sorry...

Basically turning this off stops the AF system from hunting. In low light, this is helpful, but in good light the hunting can nudge the focus a little in undesirable ways, especially with long reach lenses and especially in AI Servo. It can make the difference between sharp and slightly out.

I've played with this setting being on and off and off is where I'm at as I'm getting far more consistant AF.

It's worth a try, I'd say, nothing to loose and, as said, in my experience I'm getting far better results with it set to off.

Andrew Tingle wrote in post #14755024
I may be able to be of some assistance here

Do you have focus search on in the AF menu? If you do, try turning it off and see if that helps. On longer reach lenses this can make a pronominal difference, trust me (especially in AI servo).

Here's a quote from a website found by Google. It references the 1D Mark IV, but it should apply to all other Canon cameras as well.: http://www.wildlifeima​gesbyles.net …ide/1div_focus_​guide.html

"Custom Function III-5

This custom function allows focus search to be enabled or disabled. One of the best known bird photographers has previously made the recommendation that this custom function be disabled (on previous 1-series bodies). Evidently, the recommendation to disable focus search is contingent upon the need to pre-focus, which, to my thinking, is not practical in most situations. After trying to follow this recommendation on a number of occasions, I came to the conclusion that the recommendation was ill-conceived. I found that, when I disabled the focus search, an especially high number of pictures were either completely out of focus or, at a minimum, quite soft. To make sure that nothing changed with the 1D Mark IV, I experimented with disabling focus search on the 1D Mark IV. I found that doing so led to the same unacceptable results that it did with my previous 1-series bodies. A number of other experienced and exceptional wildlife shooters that I know and/or shoot with have come to the same conclusion. Thus, my strong recommendation is to leave this custom function permanently in the default or “0” position."

Interesting...

I'll keep mine off though as I've seen a marked improvement. Each to their own I suppose but I thought I'd offer this up as it works for me. Just trying to assist.

Andrew Tingle wrote in post #14755190
Interesting...

I'll keep mine off though as I've seen a marked improvement. Each to their own I suppose but I thought I'd offer this up as it works for me. Just trying to assist.

I sincerely appreciate your response. Apparently, this seems to be a bit of a contentious issue...

Here's someone who agrees with you:
(From Michael Guncheon's 5D Mark II Guide)

Well, at the end of the day, whatever works for each person is the answer for them. I can only give my perspective and as its a simple setting that can be set with ease perhaps you should try it, see if it works for you, or not?

I have, as said, had great results with it being off (on a 500mm) which includes bird photography, dragonflies in flight, aviation panning, etc, etc so I know what camp I'm in but, yup, whatever works for the individual.

Sometimes, in lesser light, you do have to nudge the focus manually a little. This is true, but thats only when the AF struggles and I've missed far less shots due to lost AF then I have missed AF due to this setting being on.

I'd recommend you try it.