EOS 5D MK3 ? half press shutter for focus/exposure, driving me insane, help

CambsWriter Avatar
1 Jul 2019 11:55PM
Ok, just got a Canon EOS 5D MK3 and there is one thing that's driving me nuts. I've been through the manual, the menus, but it would appear that what my old Nikon cameras (and even my friend's EOS 60D) did, the 5D MK3 can't.

What I want it to do is what my previous Nikon D3s and my friends EOS 60D do and that's when you press the shutter button half way down the focus (in one shot mode) zips into focus and holds to allow you to re-compose. Also, the exposure locks and holds at the same time as the focus so when you re-compose (keeping shutter button half pressed) both focus AND exposure do not change.

However, with the 5D MK3 when you do this as you re-compose the shot the exposure continues to change as you move the camera around, which is a pain. I know you can press the little exposure lock button on the back with your thumb as a workaround, but for me this is a pain as I have to thumble around to find it and if I'm rushing with wildlife shots I keep missing the button on the back and missing loads of shots, or getting them, but in Aperture Priority, the exposure is typically off by a stop or two.

So, is it me being thick or does the 5D MK3 not have this feature and if not, why not, as the lesser Canon APSC cameras do have this feature and so does every Nikon DSLR on the market too.

pink Avatar
pink Plus
20 7.4k 11 England
2 Jul 2019 7:06AM
I always use Manual exposure so its all under your control.
Philh04 Avatar
Philh04 18 2.3k United Kingdom
2 Jul 2019 8:20AM
AE lock is active if you use one shot AF and Evaluative metering.
CambsWriter Avatar
2 Jul 2019 9:37AM
Does it only work with Evaluative metering, not spot?
CambsWriter Avatar
2 Jul 2019 9:47AM
So, in Evaluative Metering mode if I am, for example, photographing a model, full length, but only her head is correctly lit and the rest of her body is in a lot of dark and shadow and I am taking a full-length shot, if I aim the centre of the viewfinder at her eye to gain focus and exposure, then re-compose to get her whole body in (but by now the centre of the viewfinder is at her waist in the dark) will the metering (in aperture priority mode) retain the metering it took on her face or will it stay at the centre of the viewfinder as I move the camera i.e. will my shot be seriously overexposed on her face as the meter reading area is now in the shadows of her waist?
Philh04 Avatar
Philh04 18 2.3k United Kingdom
2 Jul 2019 10:03AM
As I said... one shot AF and Evaluative metering. Personally in the situation you describe I would be working in manual probably having taken an incident reading to give a rough guide to the exposure.
CambsWriter Avatar
2 Jul 2019 10:08AM
This is true, Phil, and I work in manual most of the time, but just sometimes I need the feature I'm talking about. Thanks.
Dave_Canon Avatar
Dave_Canon 17 2.2k United Kingdom
2 Jul 2019 10:13AM
I have a 5D4 but it is almost certainly very similar. When I bought it new it did focus/set exposure with half press of shutter which was the default set up. However I decided to go for back button focusing and, after finding advice through Google, I have set this up. I used the custom settings to disable the actions for half pressed shutter. I then set the left hand top button to focussing with a single spot and lock (virtually the same as the original half pressed shutter). This allows me to lock focus and recompose before capture and is the mode I use most often. The button to the right of this is programmed for multi point and tracking so would be best for birds in flight etc. These two variations appear to allow me to operate fine. However, since setting this up, I sometimes forget to use the back button and get no focus as you have found and I also have not had the opportunity to test the second option very often yet.

I suggest you look through the customisation menus and see what has been set up. You may also be able to factory reset. Anyway I assure you that the mode you want exists and is almost certainly the default, if you can get back to it.

cuffit Avatar
cuffit Plus
16 361 8 England
2 Jul 2019 5:20PM
Hello CambsWriter, I just happen to have my Canon 5D Mk3 handbook to hand as I was looking up focussing modes. It describes what you wish to achieve but you need to keep your finger on the button while recomposing. "Suited for still subjects; when you press the shutter button half-way the camera will focus only once (at the point you set); with evaluative metering, the exposure setting will be set at the same time the focus is achieved; while you hold the shutter button down halfway, the focus will be locked - you can then recompose the shot if desired. (Page 70 of the manual). Is the answer in that last sentence, you need to keep the finger on the button to recompose in this situation which is counter to your Nikon.

I use back-button focussing which separates the functions and I can take my finger off and recompose until ready to fire the shutter. It's a while since I set up my camera and tend not change much, but it might be worth going into the custom controls (Orange section page 2 at the bottom); I can get there directly by pressing Q when the Quick Control Page is showing on the rear screen. Have a look at the settings and you may find what you want, or combination of button selections - acknowledging that you don't like the back-button option. It might be that the person before you had it set up differently - I think that has been mentioned before though.

I hope this helps. Apologies if this appears after several other messages saying the same thing or similar, my typing is not that quick! Chris

cuffit Avatar
cuffit Plus
16 361 8 England
2 Jul 2019 5:28PM
Hi CambsWriter, I attach a link to a video on the Custom Controls and how the buttons can be interchanged - it may reduce the time you have to wade through a manual - if you can put up with the voice that is.

YouTube Custom Controls
CambsWriter Avatar
5 Jul 2019 12:58PM
Thanks guys. Sorted.
cuffit Avatar
cuffit Plus
16 361 8 England
6 Jul 2019 5:19PM
Good to hear that you have it all worked out - can you tell us what it was in the end? Chris


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