Back to AF 101?

So, at this point, I'm way too comfortable with my 7D's autofocus system. I'm in the process of getting rid of my 7D for a 5D2, so I'm definitely going to miss the AF system that my 7D had.

Now, this has to do with concepts of autofocus. With a 7D, you can pretty much use any AF point and get an in-focus picture. You don't really need to rely on the center as much I've noticed.

With a 5D2, I imagine, I'd need to rely on the center AF point a lot more. So, it brings me to this question, if I focus using the center point, then reframe, and then take a picture, wouldn't that hypothetically throw my photo a little out of focus because of the distance the camera moved while reframing, albeit only a couple of inches to the left/right/up/down?

Just how decently can the 5D2 focus in comparison with a 7D? I've heard some crappy things about the 5D2 in regards to AF. I mean, I know it doesn't have 932834824 AF points like the 7D, but really, I don't shoot sports, I don't shoot action, and I'd rather have better dynamic range at higher ISO's, better low-light performance in general, and have the full frame advantages over the awesome AF the 7D has. I just need a functional AF that gets the job done without too much of a hassle.

My other camera is a T1i. I survived with its AF for years, and it worked just fine. Then I got the 7D and now I'm spoiled by awesome AF. I wish I could afford the 5D3, but I can't. :P Oh well!! Anyway.

Comments?

Heya,

Yes, focusing with center point & recomposing always gives the opportunity to slightly miss focus. This is not a big issue though unless you're using really thin depth of field (F1.4, F2, etc).

The 5D2 has the same old AF system as the 5D classic. They're definitely not accurate AF titans by any means compared to what we have today. But that said, all it takes is a little technique with center point focusing and you should be able to do nearly anything short of the most extreme cases of moving subjects.

You're going to be fine. As you said, you don't shoot action.

While you are re-learning how to use center-point AF without any fancy systems like the 7D has, you can start to appreciate the ISO, dynamic range, sharpness, etc, of the full frame sensor to make you feel a little warmer inside.

Very best,

MalVeauX wrote in post #17034740
Heya,

Yes, focusing with center point & recomposing always gives the opportunity to slightly miss focus. This is not a big issue though unless you're using really thin depth of field (F1.4, F2, etc).

The 5D2 has the same old AF system as the 5D classic. They're definitely not accurate AF titans by any means compared to what we have today. But that said, all it takes is a little technique with center point focusing and you should be able to do nearly anything short of the most extreme cases of moving subjects.

You're going to be fine. As you said, you don't shoot action.

While you are re-learning how to use center-point AF without any fancy systems like the 7D has, you can start to appreciate the ISO, dynamic range, sharpness, etc, of the full frame sensor to make you feel a little warmer inside.

Very best,

Wonderful. That makes me feel better already.

How does the 6D do in comparison?

quadwing wrote in post #17034762
Wonderful. That makes me feel better already.

How does the 6D do in comparison?

Heya,

The 6D has a little better center point focus, but mostly because it can grab as low as -3 EV compared to other cameras clocking in closer to -2 EV for AF, piercing the dark. The 6D is not a big AF titan either though, it's outer points are not winning any contests. None of these cameras are bad at autofocus mind you, they're just not as robust as the 7D, 5D3, and later 1D series. This isn't an issue since you're not doing action.

That said, I bird with a lowly 650D, not even a 7D, and I seem to be doing fine with a 600mm lens. Just take some time, use good technique, learn your camera, and you can do whatever it is you want to do. You just won't have an auto-system doing it for you with super ease. You will just have to put a little skill to use. No biggie. The trade off is that you now can perform better in low light and you have more control over the thinnest depth of field.

Very best,

Hory chit, -3EV? That's very useful. Definitely going for a 6D if I can.

The AF system isn't super important. Again, it's a convenience to me--that's the extent of it. I'd still rather have full frame.

I never found either the 5Dc or the 5DII AF to be inaccurate. It always seemed really accurate, just very slow and brutally slow when tracking moving subjects, especially the 5Dc.

With plenty of light the 6D's outer points work just fine. In low-light, you'll be forced to use the center point. As was said, focus-recompose is not an issue when stopped down, but wide open with paper-thin DOF, you can and will get OOF shots. It is best to use the peripheral AF points if you can.

Quad.
Several years ago I was going to add a 5D Mark II to my 7D. However I could not go back a step with the older AF of the 5D Mark II. Yes I do shoot a lot of sports and BIF, so I was spoiled with the AF of the 7D. For me the only option for full frame with AF of 7D improvements were the 5D Mark III and the 1Dx.
Since Christmas, my 7D's have been seeing less action. Looking to purchase another 5D Mark III as I am now really spoiled. Certainly the best of both worlds.

The 5D3 is showing up with some awesome deals lately - under $2500 from reliable dealers via CanonPriceWatch.

You will find either the 5D3 or the 6D to be a bit less noisy than the 7D, especially if you tend to underexpose. I expect the 6D should beat the 5D2 autofocus behavior if you're not shooting moving objects.

quadwing wrote in post #17034788
Hory chit, -3EV? That's very useful. Definitely going for a 6D if I can.

The AF system isn't super important. Again, it's a convenience to me--that's the extent of it. I'd still rather have full frame.

Yeah, the -3EV center point is really one of the best parts of the 6D, making it for a few particular uses significantly better than the 5DIII.

I would take a 6D over a 5Dii. The AF might not be that much better, but while the 5Dii has heavy noise even at 3200 ISO the 6D handles that muuuch better.

And pricewise theyre not that much apart from each other