# Canon 5D3 - spot metering - autofocus



## Tricky (May 6, 2015)

I've just started to shoot rock bands, so use spot metering to focus on the performer's eye. f/2.8 or larger. iso dependent on light, but up to 4000. speed usually 125/250 depending on movement - some move about all the time. some prime / some zoom. L series.
Can anyone advise on whether I should set the AF mode to One Shot, AI Focus or AI Servo? What differences might I expect to get? I usually shoot a burst. It is not important for me to get every shot pin-sharp as I will have about 8-10 mins in the 'pit'. It is often dark, and so metering on a dark subject can be difficult anyway, and can take some time. I don;t want the focus to reset when I compose the image - the performers eye (where I initially focus - in the centre of the camera) will be around an intersection of 3rds in the frame when I take the pic. Thanks.


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## Valvebounce (May 6, 2015)

Hi Tricky. 
Use one shot or servo, AI Focus is asking the camera to decide whether there is movement or not, a decision that you should make. 
To prevent the camera refocusing use Back Button Focus and go through the menus to set the shutter release to metering start only. 
If you are focusing, spot metering and re composing, you need to AE lock or it will re meter when you press the shutter button, as per page 173 of the manual you could use evaluative metering, focus without recompose and pick the focus point you wish to use AE lock is then tied to that AF point. 
Edit, I just re read and my assumption that you are using auto ISO may be wrong, therefore I guess AE lock is not required! 

Just some ideas from someone without a 5DIII (but I can dream can't I) who only shot one concert with a Canon A650 IS. In my defence I was told I wouldn't be able to use a DSLR many of the rest of the VIPs had theirs with them! 
I feel sure there will be better advice along shortly! ;D

Cheers, Graham.


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## sanj (May 6, 2015)

Tricky said:


> I've just started to shoot rock bands, so use spot metering to focus on the performer's eye. f/2.8 or larger. iso dependent on light, but up to 4000. speed usually 125/250 depending on movement - some move about all the time. some prime / some zoom. L series.
> Can anyone advise on whether I should set the AF mode to One Shot, AI Focus or AI Servo? What differences might I expect to get? I usually shoot a burst. It is not important for me to get every shot pin-sharp as I will have about 8-10 mins in the 'pit'. It is often dark, and so metering on a dark subject can be difficult anyway, and can take some time. I don;t want the focus to reset when I compose the image - the performers eye (where I initially focus - in the centre of the camera) will be around an intersection of 3rds in the frame when I take the pic. Thanks.



Vot?

AI Servo definitely. 

Vot again...

There is some solid re thinking required.


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## neuroanatomist (May 6, 2015)

Tricky said:


> f/2.8 or larger.
> I don;t want the focus to reset when I compose the image - the performers eye (where I initially focus - in the centre of the camera) will be around an intersection of 3rds in the frame when I take the pic.



In fact, geometry guarantees your focus will change, although your DoF may be sufficient to mask the effect. Worth a read: http://visual-vacations.com/Photography/focus-recompose_sucks.htm

You might consider spot metering then setting the exposure manually for the set (M mode, perhaps with Auto ISO).


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## YuengLinger (May 6, 2015)

Hi, Tricky, welcome to CR.

I might have similar experience shooting orchestras and choirs. Thing is, such performers stay relatively still. Soloists don't tend to jump around or sling instruments. In my situation, I use a 70-200mm 2.8 IS mostly, but also a 135mm 2.0. I generally use One Shot AF. See note below about using a Speedlite's AF assist beam.

At events where attendees are walking towards me, even in very low light, AI Servo works well.

Center point and recompose? Why? If you are using fast lenses, you are just asking for trouble, again, as pointed out by Neuro. The 5D III is so rich with AF points, I just choose the one that helps make the best composition. If you choose one near the perfect composition and then shift off it slightly after locking focus, that is still much, much better than focusing with the center point then shifting your frame by a third of its size.

The other thing easier about classical music scenarios--the lights don't change a lot. In rock concerts, I know they do. Neuro's suggestion to use Manual metering mode is excellent for any situation where you have a consistently lit subject surrounded by dark backgrounds, because if you are using Av mode, any shift of the camera will give you a different exposure value unless you use AE lock (but that is generally a major pain, cutting out when you think you are on a roll). 

But if your lights are changing a lot (during the performance rather than in the pit), Av with Partial Metering might be just right. I do use Spot Metering for portraits, but generally when the subject is staying still and I want a dramatic drop off of light. Partial Metering seems to work better for subjects that have some shadow playing on their faces and bodies or that are moving around a lot.

Now, if you have a Speedlite, you can take advantage of its AF assist beam, which helps TREMENDOUSLY. You can set the flash to Does Not Fire. Even a 430ex is very helpful, but the 600ex-rt has a beam that works better with the 5D III's AF points. (And the 580ex also has a better assist beam than does the 430ex.)

Finally, try to practice ahead of time in your home or backyard or at the venue itself if possible.

Good luck! Let us know how it went.


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## Tricky (May 6, 2015)

Many thanks for your advice and tips - so quick too. Generally, I've found gig photographers to be reluctant to share set-up tips...

I shoot Manual, and so would be constantly having attention to shutter speed (head / hair shake 250th, normal 125/160th, drummer 60/80th), iso (for graininess, thinking about effect with b/w in particular - and often poor light), aperture (throw as much out of focus as possible - but cognisant of depth of field between, say 15mm and 200mm). And so varying between these three as necessary / appropriate.

Usually, flash is not permitted, but the tip of affixing the speedily and setting a 'flash do not fire' mode is welcome. As is the tip re: One Shot and also avoiding recomposing of the shot.

A professional photographer who covers cycling (I was at an indoor arena) suggested that AF Servo doesn't work in poor light - and so would struggle at poorly lit gigs. Perhaps better lit larger venues, it may be better?

Sanj - what do you mean by 'vot'? Forgive my ignorance 

Anyone who shoots gigs - comments would be welcome too.

Thanks.


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## YuengLinger (May 6, 2015)

Tricky said:


> Many thanks for your advice and tips - so quick too. Generally, I've found gig photographers to be reluctant to share set-up tips...
> 
> I shoot Manual, and so would be constantly having attention to shutter speed (head / hair shake 250th, normal 125/160th, drummer 60/80th), iso (for graininess, thinking about effect with b/w in particular - and often poor light), aperture (throw as much out of focus as possible - but cognisant of depth of field between, say 15mm and 200mm). And so varying between these three as necessary / appropriate.
> 
> ...



The only way to know what your gear can do on a practical, working level is to get out there and use it. A set of tests test should be very easy for you to determine how low the light can go for you to have reliable use of AI Servo AF. Remember to take into account the contrast of your subject against the background. Even then, you need to know which situations give your AF more trouble, and be prepared work around them. With poor contrast in low light--basically a gray wall in near dark, the Speedlite assist beam can save you, but without it, until you test in a no-pressure situation, all the specs and advice in the world will still leave you guessing.

Could you set up some spotlights or something similar that will approximate the lighting you will encounter in your upcoming shoot? Or even go with a friend to the venue? This is the only way I'd be confident even knowing my equipment very well. Trial run, or as close as I can get to it.


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