When is 19AF points better than 9?

BarnET wrote:

Keith Z Leonard wrote:

Juardis wrote:

Keith Z Leonard wrote:

Canon cameras in the digital age that I've owned were the xti, 7D, and 5Dmk3, though I've shot quite a few others along the way. I do think you use the other AF points when you have them and are convinced that they are good. I personally use the 41 cross type setup of the 5dmk3 quite a lot. I rarely do subject tracking but when I have I know I've gotten shots that I'd otherwise never have managed. These cameras are just better than the older ones, doesn't mean the older ones are bad, or that you NEED them, but they do perform better.

So if you're shooting a moving subject, more AF points is better (with the newer bodies that is). Got it. That's a change from the T2i.

But if you're shooting a static subject, which AF points do you choose? Center? A subset of all of them? All of them?

I choose the one that puts my subject where I want them in the frame. Choosing all of them is a formula for missed shots. Generally I don't want the camera to do the thinking, that's why I have a brain.

Agreed unless going into higher end Dslr's with mofe advanced metering sensors they are just to dumb to ID human shapes. So they will pick a more or less random point that happens to have the most contrast or in close proximity to the camera.

You are thinking of the AF sensor that does that. Metering is simply based upon sampling patterns within "zones" on low end DSLRs and are based upon a secondary imaging sensor on more recent mid to high end Canon DSLRs

Doing it yourself is simply a much better idea. Unless the camera can detect the scenes properly themselves like most mirrorless and very high end dslrs.

I use my meter quite a lot and it works fine, you just have to understand how it works. Mirrorless uses the actual imaging sensor, which works well, but eats battery, of course.

There are other issues regarding focus/recompose too, like you focus on a subject, recompose, but then your metering is changed and you can miss your exposure.

When shooting fast primes wide open this is practically aying russian roulette in getting the right part in focus.

I was thinking more of quite fast moving subjects, I would never advocate using a zone or multi-point AF setup for fast primes, then you really are just hoping for the best, the Canon AF system will indeed choose the closest thing with contrast within any of the active AF points, so smaller is often better when doing thin DOF photography.

The focus plane can be very small so moving your camera after acquiring focus will cause many shots to be slightly off.

True, takes some practice, this can also be true with super telephoto lenses.

Being able to place a point on your subjects eye and then shoot is a lot more accurate.

yep

In eval metering it is biased to the active AF point, so selecting the AF point over the subject in that case could result in better exposures. Of course you can spot meter and use the lock feature, not sure that many people do this though.

Mirrorless shooters do since with eye detect they will simply do that automatically. Great feature wished affordable Dslr's could do it.

The 80D does it, 7Dmk2, 5Ds/r, 5Dmk4, 1Dxmk2

Nikon D810 D750 D500 can do it but wouldn't call those affordable.

Similiar, the mid range to expensive range DSLRs, probably going to get into a rebel soon though. Of course you could go with the m5 if you love mirrorless, looks like a good camera.