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.

[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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@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!!! 🙂 

[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.

[TCampbell]

For clarity... is this an original 7D or is the 7D II?  I ask because there are significant differences in the focus system.

When a camera is in "One Shot" AF mode *and* a lens is attached and switched to "AF" (auto-focus enabled) then the camera uses "Focus Priority" ... meaning it wont let you shoot unless it can confirm it has managed to focus on at least ONE AF point. But that's really just a temporary gate because once the camera locks focus, it stops focusing... any photographer movement AFTER the focus is achieved will not update focus  (so if she focuses & moves... then it would explain the problem.)

But if the lens is in "MF" mode or if the camera thinks no lens is attached (becuase it wasn't rotated until the locking pin engaged) then that could also explain the lack of focus.

If, instead, the camera is in "AI Servo" mode, then the camera will focus cotinuously... with the caveat that it also now uses "Release Priority".  So a quick mash of the shutter button (without pausing at the half-press point to make sure it really does focus on something) would causes it to release the shutter immedaitely... even if it didn't have adequate time to focus.

So that's another possibility.

You'll likely need to go out with her and observe how she shoots... pick a few subjects at different focus distances and have her move from object to object so that the camera is forced to re-focus.

Depending on the camaera model (7D vs. 7D II) there are differences in how the focus system works.  It *sounds* like you're using one of the "zone" focus modes and you've picked the zone in the center.  Whenever any Canon model (that I know of) is allowed the use of more than one focus point, it will tend to lock focus on the "closest" thing available (the camera assumes your intended subject of interest is the one closest to the camera) and to over-ride you'd need to switch to a focus mode that doesn't let the camera use multiple points (so now it has no choice but to focus on the thing you picked.)

[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. 

[ABBOTALE]

If it's the 7D MK1 there's a simple solution i had the same problem..1. In menu settings go to the setting second from last (pic of a  camera ) next to a white star green backgrounds Then scroll down to AUTOFOCUS/DRIVE....MICROADJUSTMENT..THEN PRESS ... DISABLE.. OK SO FAR..

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.

3 just re set time/date

[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.