6D vs 5D3, can't make up my mind...

Mornnb wrote in post #15825639
Its the easiest spot for the AF system to grab focus, and its the same distance from the camera as the lady. So I really don't see a problem with doing this.

Well I'm not trying to say the AF system is flawed, it's just that it will always has limitation, as it can't read your mind where you want to focus to be exact.

That's why I tell the camera where I want by selecting a point and never let the camera to make such decision

In that sample, I mean would you focus on the window or the lady?

The lady is clearly in front of the window and if you shot that with a large aperture with all AF points enabled, the lady will be oof if it decides to focus on the window.

From the photos and where the author placed the active point in both the 5D3 and 7D pics, it seems the focus is supposed to be on the lady and not the window.

kin2son wrote in post #15825643
In that sample, I mean would you focus on the window or the lady?

The lady is clearly in front of the window and if you shot that with a large aperture with all AF points enabled, the lady will be oof if it decides to focus on the window.

But that's what I'm saying for this shot it wouldn't matter if it focused on the lady or the window, they're both pretty close and you'll likely be shooting this at f/8 or f/10. So it's not always worth the effort to be dealing with zone AF.
Now for shots with big apertures, say f/1.4, the 5D3 does have a big advantage. And with the 6D you will likely be focus recomposing. Not because the outer AF points are useless but because odds are high they won't be over the point you want to focus on.

Mornnb wrote in post #15825654
But that's what I'm saying for this shot it wouldn't matter if it focused on the lady or the window, they're both pretty close and you'll likely be shooting this at f/8 or f/10. So it's not always worth the effort to be dealing with zone AF.

If it really wouldn't matter because you have picked the right aperture, wouldn't it be easier just stick with center point and aim at the middle of the wall?

I think a lot of potential 6D buyers are first time FFer who is looking for improved IQ and high ISO performance and putting way too much emphasis on it while totally overlooking the importance of AF.

I used to own a 5D2 and was never happy with the AF, and imo it isn't IQ or noise that makes or breaks a photo, it's whether you can achieve perfect focus

5D3 totally freed me composition-wise and can finally stop placing my subject dead in the middle or some heavy cropping just to place my subject off-center.

Mornnb wrote in post #15825628
But in this case the cameras would probably perform similarly. And would tend to grab focus on the high contrast window on the left. Only the D600 can't place a focus point over it. However the outer points on the 6D are pretty slow to grab focus.

With 'zone AF' in Auto on the 7D, wouldn't it have picked out the lady to lock onto, as, she is the nearest thing to the camera ? ? ? ?

kin2son wrote in post #15825657
If it really wouldn't matter because you have picked the right aperture, wouldn't it be easier just stick with center point and aim at the middle of the wall?

Ohh but the problem there is AF doesn't work too well for textureless surfaces like painted walls. It's going to do a better and more accurate job at grabbing focus from the window.

I think a lot of potential 6D buyers are first time FFer who is looking for improved IQ and high ISO performance and putting way too much emphasis on it while totally overlooking the importance of AF.

I used to own a 5D2 and was never happy with the AF, and imo it isn't IQ or noise that makes or breaks a photo, it's whether you can achieve perfect focus

5D3 totally freed me composition-wise and can finally stop placing my subject dead in the middle or some heavy cropping just to place my subject off-center.

This makes sense, but the centre AF point is pretty damn good and there is focus recomposing. I got the 6D, knowing this and knowing I'd have the 7D for situations I'd need AI servo.

h14nha wrote in post #15825670
With 'zone AF' in Auto on the 7D, wouldn't it have picked out the lady to lock onto, as, she is the nearest thing to the camera ? ? ? ?

If she was under one of the AF points, but she wasn't in that example. I think even the 7D and 5D3 could do with some better AF point coverage of the frame!

Mornnb wrote in post #15825628
But in this case the cameras would probably perform similarly. And would tend to grab focus on the high contrast window on the left. Only the D600 can't place a focus point over it. However the outer points on the 6D are pretty slow to grab focus.

Correct. If all AF points are enabled, the AF system will focus on the thing that is closest to the camera and has enough contrast to focus on.

Mornnb wrote in post #15825654
But that's what I'm saying for this shot it wouldn't matter if it focused on the lady or the window, they're both pretty close and you'll likely be shooting this at f/8 or f/10. So it's not always worth the effort to be dealing with zone AF.
Now for shots with big apertures, say f/1.4, the 5D3 does have a big advantage. And with the 6D you will likely be focus recomposing. Not because the outer AF points are useless but because odds are high they won't be over the point you want to focus on.

When you focus&recompose using the center AF point at F/1.4 on a 6D, there's a pretty good chance that your subject will be (slightly) out-of-focus because of the very small DoF and the change in focal plane due to focus&recompose. Safest method for that kind of situation on a 6D would be to use Liveview.

kin2son wrote in post #15825657
If it really wouldn't matter because you have picked the right aperture, wouldn't it be easier just stick with center point and aim at the middle of the wall?

I think a lot of potential 6D buyers are first time FFer who is looking for improved IQ and high ISO performance and putting way too much emphasis on it while totally overlooking the importance of AF.

I used to own a 5D2 and was never happy with the AF, and imo it isn't IQ or noise that makes or breaks a photo, it's whether you can achieve perfect focus

5D3 totally freed me composition-wise and can finally stop placing my subject dead in the middle or some heavy cropping just to place my subject off-center.

Well that's exactly why I'm leaning more towards the 5D3 at the moment. I use the 6 most outer AF points on my 550D the most (3 most left and 3 most right) since I don't like centered subjects (boring composition, static picture). They work fine as long as light is decent and contrast patterns are running in the right direction. Of course you could center your subject and (heavily) crop afterwards but what if you just took "the shot of your life". It would mean that after cropping you wouldn't be able to print as large as you would have when you wouldn't have cropped the image.

Mornnb wrote in post #15825698
Ohh but the problem there is AF doesn't work too well for textureless surfaces like painted walls. It's going to do a better and more accurate job at grabbing focus from the window.

Correct. There has to be enough structure and contrast in an image for AF to work. A wall in a solid color often gives infinite hunting.

As much as I love my camera up to this point, the coverage of AF points has been a bit of a bummer to me. I have been looking for opportunities to use the outer AF points more and have yet to be disappointed in their performance but I do wish they weren't so crammed into the center.
My 60d covers considerably more of the frame and I liked that very much, used the outer points often when not shooting sports or BIF.

Some funny comments in these thread, 5d3 is not just joistick with AF It is 41 cross type focus points vs 1, it is 1/8000 vs 1/4000 shutter, it is 100% viewfinder vs 97%, it is larger glass finished LCD vs plastic, it is fully metal body vs plastic top, it is CF card vs cheesy single SD, slower fps on 6d ... etc. If you don't need anything, shot with PS it is also cheap and missing all your don't needs.

One thing I only like in 6d is size...

Mornnb wrote in post #15825698
If she was under one of the AF points, but she wasn't in that example. I think even the 7D and 5D3 could do with some better AF point coverage of the frame!

Except that the AF points on the 7D are bigger than what you see in the viewfinder so it probably would have picked the lady out

Body comes out regularly... just get what u like, try it, dont like? Sell get the other.... a few hundreds shots wont make the body depreciate much.

Ok, a new episode in my story of choosing the right camera... Went to another hypermarket today since I needed rechargeable batteries for my Pocket Wizard FlexTT5. I noticed some demo cameras e.g. 60D, 700D, 7D, 6D... Sadly enough no 5D3 (at least no demo camera).

The 7D was equipped with the EF-S 18-135mm F/3.5-5.6 IS. I found this combo rather heavy. Should weigh about 1275gr together (body 820gr, lens 455gr). The 5D3 body is even heavier (950gr) so now I'm thinking: do I want this heavy body? I definitely want its AF system, but am I willing to bare with the weight?

Then I played around a bit with the 6D (don't know anymore which lens was on it). This combo felt much lighter. I tested the AF system for a while. Focusing close and immediately after that focusing at a distance and this multiple times with both the center AF point and with the most-right AF point. Focus speed was good (but not faster than my 550D).

I also tried focusing on the grip of a Nikon DSLR with the center AF point and with the most-right AF point and here the AF system of the 6D often failed to lock on when the most-right AF point was used (while the 60D had no problem with this when I also used the most-right AF point). I guess that's the limitation of being a non-crosstype AF point (or the 6D just doesn't like a Nikon DSLR). The spread of the AF points on the 6D was surprisingly decent (didn't feel too much centered, although the spread of the AF points on the 7D was nicer).

Oh boy, it looks like this is gonna take a while. Where the 6D has been in the background for me for a couple of months now, it just jumped back to the foreground today. The top dial on the 6D also felt much nicer than the top dial on my 550D (550D top dial has too much resistance). There is however a thing I don't like about the 6D and it's the way you switch between AF points. The top dial scrolls through AF points horizontally, while the dial on the back scrolls through AF points vertically. In the worst case scenario you'll have to use both dials to select the AF point you want (on my 550D I can select any AF point I want using the top dial).

^You can also just use the multi-controller to select AF points, that's what I usually do

Honestly if I were you I'd just make a decision. Either camera will be an excellent upgrade to your 550D (same upgrade I made) and the longer you wait the less time you're taking pictures with an amazing tool. I leapt on my 6D as soon as I could afford to and no part of me regrets it, if for some reason I find in the future that I need the crazy AF of the 5DIII (don't see that happening for me) then I'll save up and get one or supplement my 6D with a 7D.

1dx is the best dslr canon can offer, 5dmk3 has the same focus system, just that alone should justify your buy.

"For months I've been wondering" COME ON GET OFF THE POT AND GET A CAMERA ALREADY!!!!