choosing AF points

I have the 30D and was wondering if you could choose 3 AF points (I would prefer the 3 horizontal points- far left-center-far right) or can you only choose 1 at a time? (or all 9 at a time as I already know).
Thanks.

1 at a time only.

Yup - all 9, or any 1. That's it.

Yep... one at a time or all only... What I found that works best is to leave it on center AF point only. Focus, and recompose... but that's not for everyone.

The center focus point will give you better accuracy with f2.8 or faster lenses.

Out of curiosity, why are you interested in picking the 3 horizontal focus points?

ps249 wrote in post #4207808
I have the 30D and was wondering if you could choose 3 AF points (I would prefer the 3 horizontal points- far left-center-far right) or can you only choose 1 at a time? (or all 9 at a time as I already know).
Thanks.

The lens focuses on a plane so if you get one item in focus, everything else in the same plane will also be in focus. If you use all 9 points then different points will light up showing what is in the plane of focus. Can be a bit fiddly if you're trying to position yourself to get a row of things in focus, but provided they are in the same plane, the 9 point option will help you achieve this.

I prefer just to judge with my eye and use the focus point nearest to the area I want, but can see there are some situations where using more than one focus point is very useful.

JackProton wrote in post #4209150
The center focus point will give you better accuracy with f2.8 or faster lenses.

Out of curiosity, why are you interested in picking the 3 horizontal focus points?

it seems to me that those 3 would work best in my photography.

Because you wanted objects at those particular three AF points to all be in focus?

ps249 wrote in post #4207808
I have the 30D and was wondering if you could choose 3 AF points (I would prefer the 3 horizontal points- far left-center-far right) or can you only choose 1 at a time? (or all 9 at a time as I already know).
Thanks.

You can only choose either one point or all points. If you choose one point, the camera fixes on one plane of focus, and your aperture setting (as well as distance from your subject and your focal length) determines how much depth-of-field you will have ( how much of your image will appear as sharp). When you choose all focal points, the camera does a best-guess, with an emphasis on the center point, at what the best focal point will be.

Normally, all focal points chosen is an "I don't care" setting, as in they're all infinity or the equivalent relatively, so pick a point, whereas picking a point ensures that one particular plane of focus will be sharp, no matter what the aperture is.

Hope this helps!

Tony

I'm using the multicontroller to select the focus point, but I often miss and have to press again to hit the point I want.

Does anyone find the wheel on the back to be the faster way altogether? (CFn-13/2 on the 30D)

I started with the wheel but it was too slow - it just goes through the options one by one. The more I use the jogwheel (multicontroller) the quicker I am. Seems to take a bit of practice. Perhaps it would be easier if the botton was shaped differently - something for the next model?

I too use the multi-controller... I'm much quicker with it and can change the AF point without taking my eye out of the viewfinder.

Another one here for multi-controller

BogongBreeze wrote in post #4210322
I started with the wheel but it was too slow - it just goes through the options one by one. The more I use the jogwheel (multicontroller) the quicker I am. Seems to take a bit of practice. Perhaps it would be easier if the botton was shaped differently - something for the next model?

I agree, Miriam.

A larger multicontroller top surface would make choosing the right direction easier.

Multicontroller joystick all the way.