5D Mark ii autofocus fails - why doesn't full time manual focus let me take the photo


KarenChii

New Member
Feb 26, 2011
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I have the 5D Mark ii and the 24-105mm lens (which has full time manual focus). The 5D Mark ii sometimes fails to take the picture if its autofocus fails (something my Rebel XSi seems to do better with, but whatever). When this happens, why can't I just tap the focus ring to override the autofocus and then take the picture? Even when I move the focus ring, it still does not take the stupid picture when I press the shutter. When I switch to manual focus it takes the pictures perfectly.

I thought that was how full time manual focusing worked? Why won't it take my picture?

Does anyone have any other suggestions for getting the camera to actually take the picture when autofocus fails?
 

"did your dial positioned correctly and also your manual focus switch? was your len securely mounted?"

Do you mean the autofocus vs manual focus switch on the lens? It was in autofocus because I'm trying to use the full time manual focus which means you can manually focus while in autofocus mode. If it's in manual focus it works fine.

I'm pretty sure my lens was securely mounted. It works in manual mode.

I don't know what you mean about the dial positioned correctly. Which dial?
 

did you put it on one-shot AF?
 

No it was on Al-Focus I believe. Would it take the picture if it was on One-Shot? Al-Focus should only refocus if the subject is moving which it wasn't.

I don't think it was even refocusing but I could be remembering incorrectly. Just when I press the shutter it doesn't take the picture. Very frustrating.

This is in a dark, low contrast place, but still, my question is: how do I make the fulltime manual focus work like manual focus and just take the picture if I want the camera to just *take the picture* without having to physically switch the lens to Manual Focus and then back again every time it fails.
 

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Your autofocus might be set to something like focus priority. Meaning camera will refuse to fire until it achieves focus lock.
That's a possibility I suppose.
 

Ok, how do I undo this focus priority?

I looked through the custom functions and couldn't find anything like this. In the manual it says something like "when autofocus fails, sorry we suck, and please don't sue us for the lost pictures. Try manual focus." So not helpful. Sorry. I'm frustrated. Still trying to make my very expensive 5D Mark ii reliable...

I don't think I'm knowledgeable enough to say whether or not mine is a little bit broken. But do you think I have a bad copy of the 5D Mark ii? Or do they all require unsuccessful shutter mashing from time to time unless switched to manual focus on the lens? I'm sort of afraid I am going to break it because when I'm pressing the shutter unsuccessfully it's usually harder than usual since it's not *working* and it doesn't help that I'm pissed off. I suppose the solution would be for it to just work.
 

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under custom functions

C.Fn. III - Autofocus/Drive -> Lens Drive when AF Impossible
 

Set it to AI servo and I believe you should be able to release the shutter.
 

Set it to AI servo and I believe you should be able to release the shutter.
you cannot do FTM focusing on AI-Servo.
 

i am a nikon user so not very sure about the canon 5d2 manual / abbreviations

go to the menu and change your AF-S mode (Single shoot mode)
from focus only to release only

hence even not in focus u can still press the shutter and record the image
such that u can manual focus override and record images at the same time

this also means that there will be no focus beep sound

- - -

some may go to the extend to change the AF activation to AF-ON Only
but its up to you

it means now u focus with the AF-ON instead of the Shutter button
no more half press and then shoot
 

under custom functions

C.Fn. III - Autofocus/Drive -> Lens Drive when AF Impossible



Will this allow the shutter button to take the picture no matter what? (I thought I tried this, but it just stopped hunting - didn't let me take the picture)



"go to the menu and change your AF-S mode (Single shoot mode)
from focus only to release only

hence even not in focus u can still press the shutter and record the image
such that u can manual focus override and record images at the same time

this also means that there will be no focus beep sound "

This sounds useful - does this exist on the 5D Mark ii?
 

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can you just go and try putting it on one-shot AF and see how first?
 

Unfortunately I don't have my camera with me at the moment but tonight I will give it a try.

Oh, also, I emailed the Canon customer service and they said that full time manual focus only works after the focus has been locked.

But I'm still looking for how to get the shutter to release more reliably in general (I was in a dimly lit room sort of, at nighttime, with the ceiling light on and I photographed an object shape - not like a wall - and it still took a few tries even though it seemed good enough in the viewfinder)
 

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Your autofocus might be set to something like focus priority. Meaning camera will refuse to fire until it achieves focus lock.
That's a possibility I suppose.

Ok, how do I undo this focus priority?

I looked through the custom functions and couldn't find anything like this. In the manual it says something like "when autofocus fails, sorry we suck, and please don't sue us for the lost pictures. Try manual focus." So not helpful. Sorry. I'm frustrated. Still trying to make my very expensive 5D Mark ii reliable...

I don't think I'm knowledgeable enough to say whether or not mine is a little bit broken. But do you think I have a bad copy of the 5D Mark ii? Or do they all require unsuccessful shutter mashing from time to time unless switched to manual focus on the lens? I'm sort of afraid I am going to break it because when I'm pressing the shutter unsuccessfully it's usually harder than usual since it's not *working* and it doesn't help that I'm pissed off. I suppose the solution would be for it to just work.

Chill :)
Your camera is certainly not lousy in any way. In fact, as a "serious" camera, it offers a wealth of settings for you to customize to your liking.

2 things to note:
1) auto-focus is slightly handicapped in the environment that you described, dimly-lit and with little contrast.
2) camera is usually defaulted to inhibit capture of image until focus-lock is achieved.

On my camera (not Canon :)) there is an option called "AF-S Priority Selection" which is described as follows:
This option controls whether photographs can be taken only when the camera is in focus (focus priority) or whenever the shutter-release button is pressed (release-priority) in single-servo AF.

edit: setting 'release-priority' is not necessarily a good thing, since you may capture many shots that are out of focus, thus causing further frustration ("why my expensive camera cannot take sharp photos???")
 

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But I'm still looking for how to get the shutter to release more reliably in general (I was in a dimly lit room sort of, at nighttime, with the ceiling light on and I photographed an object shape - not like a wall - and it still took a few tries even though it seemed good enough in the viewfinder)

I think you expect some magic where there is simply not enough light. The AF sensors that will recognize patterns and tell the lens how to achieve focus need a certain amount of light. If there is not enough light then what do you expect them to do? You can support the AF system by using an external flash and its red pattern light (AF assist beam). Your camera can be set in a way that only the AF assist works, but no flash is fired. Alternatively, any other source of light can do the same. Under such dim conditions you will use a tripod (likely), so you can focus first, then switch off all assist lights and meter for exposure.
 

talk is cheap, TS you try out the suggested solutions liao bo???