Canon 5DMk2 focus issue

wippers

wippers

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Gareth
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Hi all - This may sound like a bit of a beginners question, but when I half depress the shutter button should this lock my focus up so I can then recompose the shot?
Currently when I half depress the button, it locks on to what I'm focusing on no problem, but when I move to recompose the shot (with my finger still half pressing the button) it re-focuses.

I have the camera set to "one shot" and a centre focus point only.

I'm sure my 50D never did this? :shrug:

Gareth
 
change to back button focus and you never need to be half cocked again
 
Custom function 4

Takes a little getting used to.

before you do that though, try the AF lock button on the back of the 5DII next to the * button.
 
arad85 said:
Just tried that with my 5D2 and it definitely does NOT refocus. Are you sure you are on one shot and are you sure it isn't you "seeing" the IS kicking in when you recompose the image?

As to button config, it's a Custom Function. You can find out more about it here: http://www.usa.canon.com/dlc/controller?act=GetArticleAct&articleID=2286
Click to expand...

Definitely refocusing. I was taking a photo of some long thin drilled steel plates for work and wanted to focus on the centre to make the drilled holes nearest and furthest away look out of focus. When I moved to recompose, the camera wanted to re-focus on the place where the new centre point focus was.
Am I going mad? :bonk::shrug:
 
If you're sure it's refocusing and on one shot (check again, it might have nudged over to one of the AI modes) I'd have it looked at as it should do what you want it to do...
 
Just tried it again now outside and it seems to be ok. :bonk:
One thing I have just thought though, is that when I was having the problems last night I was under studio model lights. Could the lack of light have made the camera try to refocus or "hunt" for focus even though the button was depressed?
 
wippers said:
One thing I have just thought though, is that when I was having the problems last night I was under studio model lights. Could the lack of light have made the camera try to refocus or "hunt" for focus even though the button was depressed?
Click to expand...
Low light may mean the focus takes longer to achieve. Had you waited for the focus confirmation beep before moving the camera? If you recomposed before the camera had thought it had found focus, you would have been recomposing as it was still focusing.
 
OK so now I've changed the AF in custom settings 4 so that the "AF-ON/AE lock button switch" is now on "1" but my half depressed shutter button still overides and refocuses. Should I be changing another setting or something to prevent the shutter button from focusing?
 
wippers said:
OK so now I've changed the AF in custom settings 4 so that the "AF-ON/AE lock button switch" is now on "1" but my half depressed shutter button still overides and refocuses. Should I be changing another setting or something to prevent the shutter button from focusing?
Click to expand...
No, you should be on settings 2 or 3. 1 is "1: Metering + AF start / AF stop" The way to read it is anything before the / is what the shutter button does on half press, everything after the / is what the AF button does on pressing.
 
I think it's 3

As I say try using the AF-Lock button on the back of the camera
 
Read this.
it explains the wording.

http://www.usa.canon.com/dlc/controller?act=GetArticleAct&articleID=2286

0: Metering + AF start (note: there’s no slash here)

Factory-default setting. You activate camera’s meter and AF by pressing shutter button half-way down. Rear AF-ON button also does same if it’s pressed, so you don’t get the benefits of removing AF activation from the shutter button when this option is set.

1: Metering + AF start / AF stop

AF is still at shutter button. Pressing the rear button will actually LOCK the focus; potentially useful if you shoot a lot of moving subjects in AI Servo AF and prefer to activate AF with a conventional half-press of shutter button. Focus is unlocked by removing thumb from back-button.

2: Metering start / Meter + AF start

Back-button AF activation. Shutter button no longer activates AF, but of course fires the shutter. Metering is continuously updated — if you shoot a sequence of pictures, the camera takes a fresh meter reading for each one. There’s no locking of exposure, unless you separately press the AE Lock button (this last item is not possible on some EOS models).

3: AE Lock / Metering + AF start

Back-button AF activation. Difference between this setting and option 2 directly above is that when you press the shutter button half-way, your exposure is locked and won’t change until you pull your finger off the button entirely. Thus, if you shoot a sequence of pictures in any auto exposure mode, the exposure setting used for the first shot is used for each subsequent shot. Can be useful if you were using back-button AF to easily lock focus and shoot a series of portraits, where you wouldn’t expect lighting to change.

4: Metering + AF start / Disable

Similar to setting “0” above, but now, the camera’s rear AF-ON button is disabled. AF activation is at the shutter button. Convenient if you’re worried about accidentally pressing the back-button and don’t want to use back-button AF.
 
Note, you can also save this menu item to "my menu" and configure "my menu" to appear when you press the menu button, so your most used options are right there with one button press.
Alternatively, use the custom settings on the dial, C1, C2, C3, which save ALL the camera settings.

I have one set up for low light 6400, single shot, centre point, F/2.8 Av mode, and another set up for shuter priority, 1/1000, AI servo etc.
I really would recommend reading the manual!
 
Cheers Andy. Really helpful. I'm not sure which of the 2 or 3 setting will suit me best. I'll have to have a read up in the manual to clarify in my head what they both do exactly.
Definitely the better way to focus lock. :thumbs:
 
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