Thoughts on focus problem

[coachboz68]

7D + 70-200L.  But I don't think it's the body or lens problem, per se. 

My daughter was out shooting today.  She's learning.  Pretty new still.  Came back and 80% of her pics were not just out of focus, but there was no focus lock achieved (could tell by turning on the AF Point Display in camera playback).  She's using shutter-button focus.  Mind you, this wasn't that it was back- or front-focused... the whole picture was out of foucs with no focus-point lock achieved.  She was in center-mass focus point grid (next-to-the-last of the focus point options) and from the look of her pictures, even in AI Servo mode, it should have acquired *something* in the image.  she was plenty far back, so I don't think it was a focusing distance problem. 

I tested it tonight when she got home and everything was working fine.  Even in AI Servo mode. 

My theory is that she did not put the lens on properly (she still struggles getting it on correctly) and something wasn't communicaing between the camera and the lens.  But that's just a theory as I cannot recreate it.  Could that have happend?  Or is the lens either on properly or not at all?  (a very few of the pics did show focus lock)

If anyone else has any speculations, I'm open to it.  She's a novice, so anything is possible.  🙂 

Billy

[Waddizzle]

Set the camera to Green [A] mode, and let her go out again.  Go with her if you can.

It sounds to me like the camera was in AI Servo focusing modem, which does not wait for the camera to focus.  Instead of half pressing the shutter to allow the camera to focus, she could have been immediately fully depressing the shutter.

It is also possible that the lens could have been set to MF, too.  The EXIF data can confirm or deny all of these assumptions.

[coachboz68]

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@Waddizzle wrote:

It sounds to me like the camera was in AI Servo focusing modem, which does not wait for the camera to focus.  Instead of half pressing the shutter to allow the camera to focus, she could have been immediately fully depressing the shutter.

It is also possible that the lens could have been set to MF, too.  The EXIF data can confirm or deny all of these assumptions.

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Pressing too quickly is a good guess and I thought about that one.  It was such good lighting and she was doing outdoor portrait shooting, so it should have acquired quickly... at least that was my thinking.  I shot sports with that camera+lens combo for nearly 10 years before giving it to her.  It acquires fast.  But like I said, she's new, so anything is possible.  

I checked the lens first thing and the EXIF data.  It was in AF.  And after a long string of completely missed shots, suddenly she would have 3-4 that did obtain focus lock.  That's what made me thing improper mount.  

I do try to go with her, but she's home from college on summer break and that dang day job of mine keeps getting in the way of my photography!!! 🙂 

[RobertTheFat]

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@coachboz68 wrote:

7D + 70-200L.  But I don't think it's the body or lens problem, per se. 

My daughter was out shooting today.  She's learning.  Pretty new still.  Came back and 80% of her pics were not just out of focus, but there was no focus lock achieved (could tell by turning on the AF Point Display in camera playback).  She's using shutter-button focus.  Mind you, this wasn't that it was back- or front-focused... the whole picture was out of foucs with no focus-point lock achieved.  She was in center-mass focus point grid (next-to-the-last of the focus point options) and from the look of her pictures, even in AI Servo mode, it should have acquired *something* in the image.  she was plenty far back, so I don't think it was a focusing distance problem. 

I tested it tonight when she got home and everything was working fine.  Even in AI Servo mode. 

My theory is that she did not put the lens on properly (she still struggles getting it on correctly) and something wasn't communicaing between the camera and the lens.  But that's just a theory as I cannot recreate it.  Could that have happend?  Or is the lens either on properly or not at all?  (a very few of the pics did show focus lock)

If anyone else has any speculations, I'm open to it.  She's a novice, so anything is possible.  🙂 

Billy

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Your speculation about incomplete mounting of the lens is at least conceivable. Various users have complained in this forum that their lens fell off during a shoot, and incomplete mounting may be the most plausible explanation. But the more usual cause of your reported symptoms is accidentally having the lens set to MF. Newbies have even been known to confuse that setting with the "M" setting on the camera.

[coachboz68]

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@RobertTheFat wrote:

But the more usual cause of your reported symptoms is accidentally having the lens set to MF. Newbies have even been known to confuse that setting with the "M" setting on the camera.

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That was my first thought as well.  It's funny when teaching someone new, I forget how many things I do routinely now during a shoot to ensure things are the way I want them.  I told her practice is the best solution!  I remember one time I came back from a beach shoot with completely blown out exposures.  The sun was so bright that on my screen during fast shooting everything looked fine at-a-glance.  After that, hello histogram on my playback screen.  🙂 

[kvbarkley]

Do NOT assume that the camera not showing focus points on playback is due to no focus point being selected. Generally the camera won't even shoot when that happens.

For some reason, Using distortion correction prevents the camera from showing the focus points. They do show up in DPP, though. Turn off distortion correction and try again.

[coachboz68]

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@kvbarkley wrote:

Do NOT assume that the camera not showing focus points on playback is due to no focus point being selected. Generally the camera won't even shoot when that happens.

For some reason, Using distortion correction prevents the camera from showing the focus points. They do show up in DPP, though. Turn off distortion correction and try again.

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I'll check disortion correction and give it a go.  What I can tell from the dataset of 250 pictures is that the ones that do show the locked focus point on the LCD in-camera are, in fact, in focus.  While the others that don't show it are not... and not just by a little bit.  Quite a lot out of focus such that nothing in the image is sharp (i.e. no back- or front-focus issues.) 

I appreciate the thought experiment.  With her being new, it's so hard to randomly guess.  So I appreciate the feedback. 

[ebiggs1]

Coach Billy,

As you can tell, you got many guesses.  One or more might be correct but the only way to know and help her out is to go with her and watch what she does.  Its good to guess, I guess, but its better to know.

"2. In the battery compartment there is a second battery it's on the flat side of the compartment take it leave it out for 10 mins then put it back in your problems will be solved."

What in the world would this do except reset the camera to defaults?  You can do that in the Menu under the Tools tab. It will solve nothing.

[coachboz68]

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@ebiggs1 wrote:

Coach Billy,

As you can tell, you got many guesses.  One or more might be correct but the only way to know and help her out is to go with her and watch what she does.  Its good to guess, I guess, but its better to know.

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Ernie, yep.  As I said, this one is a thought experiment.  I have been taking her out to teach her, which is why I know this is likely user error.  (or I think y'all call that "OP" for operator?).  I'm wired with a bit of an investigative gene (software engineer by trade) that probably makes me more inclined to play detective than any of this merits.  "Bug hunting" as we call it. 🙂  

I love all the guesses, though.  Helps me learn.  

[ebiggs1]

"I love all the guesses, though.  Helps me learn."

One thing I would rule out is not mounted corectly.  I really doubt that is the correct "guess".  But who knows, I guess?    Good luck.