6D autofocus capabilites: let's bust some myths about it

[RLPhoto]

- The 6D's -3 EV lowlight sensitivity is currently unmatched by any DSLR on the market

If you shoot lowlight, sunsets, night photography or landscape photography the lowlight AF performance on the 6D wins.

As I pointed out a few pages ago in this thread:

How do you define 'low light'?  For example, the difference between shooting at -2 EV and-3 EV could mean 1/15 s, f/2.8, ISO 51200 vs. 102400.  Neither is very usable from an IQ standpoint.  What most people call 'low light' is generally substantially brighter than either spec.

Long exposure night photograpy might benefit from that extra stop of AF capability (but in that situation, you are on a triod and probably using Live View to focus anyway).  Sunsets, landscapes and general shooting have plenty of light relative to the AF sensitivity of even lower end dSLRs. 

I think the -3 EV spec of the 6D is Canon saying 'we did it because we can, and to throw a bone after otherwise limiting AF functionality of this body' - it looks good on paper, but is of little practical benefit in the vast majority of shooting situations.

As I've said many times, due to the low noise of the 6D, the low light sensitivity of the center AF point, can be very useful in the majority of situations where you are shooting wildlife (or people) around, before, or after sunset.  Or else if you are shooting landscape hand-held, with an IS lens, up to an hour after sunset...or during a full moon.  Or if you are shooting inside a club, or outside on a dimly lit city street at night, that -3EV capability is very useful.

ISO 6400 is extremely usable for professional prints via the 6D (with a bit of post processing), and ISO's a bit above that are still useful.

As for bashing the other AF points on the 6D, you need to bash the 5D2's as well, because they were no better.  It might not still be on sale, but plenty of forum readers still own and use the 5D2.

For anyone shooting with strobes, or shooting fast sports action in well lit areas, the 5D3 or 1DX is the camera you need (or perhaps a D800 at low ISO).

If you're shooting portraits with an f/1.4 lens, wide open at f/1.4, and require peripheral AF points to be used (for focusing on eyes, etc.), then yes the 6D will not give consistent results.  But then the 1DX and 5D3 don't fare much better in that situation, which is why serious portrait photogs who shoot this way, either manually focus, or use live view.  Of course most of them are closing that fast lens down quite a bit, in which case there is more wiggle room for AF inaccuracies.

And besides, in that peripheral area of these lenses (other than the Zeiss Otus)...those eyes that you claim are so razor sharp...actually are not, and are suffering from coma and astigmatism.  It's unavoidable...especially with such lenses as the 50L and 85L.

This was fine until you mentioned the 5D3 not being much better than the 6D for f/1.4 portraits using the outer AF points. The 5D3 makes the 6D look broken doing this and it's a shame a 60D or a 7D would also make the 6D look broken.

[bdunbar79]

RLPhoto,

To further add, my 1Ds3 and 1Dx never miss at f/1.4 on the outter points.  Never.  Always exact.  No variability.  Nails it everytime and that's even without AFMA. 

[Dylan777]

- The 6D's -3 EV lowlight sensitivity is currently unmatched by any DSLR on the market

If you shoot lowlight, sunsets, night photography or landscape photography the lowlight AF performance on the 6D wins.

As I pointed out a few pages ago in this thread:

How do you define 'low light'?  For example, the difference between shooting at -2 EV and-3 EV could mean 1/15 s, f/2.8, ISO 51200 vs. 102400.  Neither is very usable from an IQ standpoint.  What most people call 'low light' is generally substantially brighter than either spec.

Long exposure night photograpy might benefit from that extra stop of AF capability (but in that situation, you are on a triod and probably using Live View to focus anyway).  Sunsets, landscapes and general shooting have plenty of light relative to the AF sensitivity of even lower end dSLRs. 

I think the -3 EV spec of the 6D is Canon saying 'we did it because we can, and to throw a bone after otherwise limiting AF functionality of this body' - it looks good on paper, but is of little practical benefit in the vast majority of shooting situations.

As I've said many times, due to the low noise of the 6D, the low light sensitivity of the center AF point, can be very useful in the majority of situations where you are shooting wildlife (or people) around, before, or after sunset.  Or else if you are shooting landscape hand-held, with an IS lens, up to an hour after sunset...or during a full moon.  Or if you are shooting inside a club, or outside on a dimly lit city street at night, that -3EV capability is very useful.

ISO 6400 is extremely usable for professional prints via the 6D (with a bit of post processing), and ISO's a bit above that are still useful.

As for bashing the other AF points on the 6D, you need to bash the 5D2's as well, because they were no better.  It might not still be on sale, but plenty of forum readers still own and use the 5D2.

For anyone shooting with strobes, or shooting fast sports action in well lit areas, the 5D3 or 1DX is the camera you need (or perhaps a D800 at low ISO).

If you're shooting portraits with an f/1.4 lens, wide open at f/1.4, and require peripheral AF points to be used (for focusing on eyes, etc.), then yes the 6D will not give consistent results.  But then the 1DX and 5D3 don't fare much better in that situation, which is why serious portrait photogs who shoot this way, either manually focus, or use live view.  Of course most of them are closing that fast lens down quite a bit, in which case there is more wiggle room for AF inaccuracies.

And besides, in that peripheral area of these lenses (other than the Zeiss Otus)...those eyes that you claim are so razor sharp...actually are not, and are suffering from coma and astigmatism.  It's unavoidable...especially with such lenses as the 50L and 85L.

This was fine until you mentioned the 5D3 not being much better than the 6D for f/1.4 portraits using the outer AF points. The 5D3 makes the 6D look broken doing this and it's a shame a 60D or a 7D would also make the 6D look broken.

+1 with RLPhoto, I have no problem with outer AF points on my 5D III. Doesn't matter 85L II or 50L

Photo below was taken with 5D III + 50L, outer AF point @ f1.2. Oops...sorry, that was f1.2 not f1.4 as he mentioned

[neuroanatomist]

If you're shooting portraits with an f/1.4 lens, wide open at f/1.4, and require peripheral AF points to be used (for focusing on eyes, etc.), then yes the 6D will not give consistent results.  But then the 1DX and 5D3 don't fare much better in that situation, which is why serious portrait photogs who shoot this way, either manually focus, or use live view.  Of course most of them are closing that fast lens down quite a bit, in which case there is more wiggle room for AF inaccuracies.

And besides, in that peripheral area of these lenses (other than the Zeiss Otus)...those eyes that you claim are so razor sharp...actually are not, and are suffering from coma and astigmatism.  It's unavoidable...especially with such lenses as the 50L and 85L.

This was fine until you mentioned the 5D3 not being much better than the 6D for f/1.4 portraits using the outer AF points. The 5D3 makes the 6D look broken doing this and it's a shame a 60D or a 7D would also make the 6D look broken.

+1

The 6D and a fast prime shot wide open are not a good combination - you either use a peripheral AF point and risk missing focus frequently (assuming there's even an AF point close to where you need it), or use the center point and recompose and guarantee backfocused shots.

As for sharp eyes with the 85L...

[Marsu42]

As I stated, the majority of situations which people call "low light" really offer plenty of light for the AF systems of even low-end dSLRs.  The extra one stop of sensitivity that the 6D has is an advantage only in very rare situations, so rare that many 6D users probably have not ever experienced them.

Having shot with the 6d and my 70-300L I changed my opinion and would disagree here:

The 6d still af's in dim light @f5.6 aperture just fine w/o af assist, and the exposure was taken care of with some flashes and iso 6400. For the big boys with constant f2.8 zooms pr even faster primes that might not matter that much, but for the cheap rest of us 1 more stop of af capability can come in handy

[CarlTN]

- The 6D's -3 EV lowlight sensitivity is currently unmatched by any DSLR on the market

If you shoot lowlight, sunsets, night photography or landscape photography the lowlight AF performance on the 6D wins.

As I pointed out a few pages ago in this thread:

How do you define 'low light'?  For example, the difference between shooting at -2 EV and-3 EV could mean 1/15 s, f/2.8, ISO 51200 vs. 102400.  Neither is very usable from an IQ standpoint.  What most people call 'low light' is generally substantially brighter than either spec.

Long exposure night photograpy might benefit from that extra stop of AF capability (but in that situation, you are on a triod and probably using Live View to focus anyway).  Sunsets, landscapes and general shooting have plenty of light relative to the AF sensitivity of even lower end dSLRs. 

I think the -3 EV spec of the 6D is Canon saying 'we did it because we can, and to throw a bone after otherwise limiting AF functionality of this body' - it looks good on paper, but is of little practical benefit in the vast majority of shooting situations.

As I've said many times, due to the low noise of the 6D, the low light sensitivity of the center AF point, can be very useful in the majority of situations where you are shooting wildlife (or people) around, before, or after sunset.  Or else if you are shooting landscape hand-held, with an IS lens, up to an hour after sunset...or during a full moon.  Or if you are shooting inside a club, or outside on a dimly lit city street at night, that -3EV capability is very useful.

ISO 6400 is extremely usable for professional prints via the 6D (with a bit of post processing), and ISO's a bit above that are still useful.

As for bashing the other AF points on the 6D, you need to bash the 5D2's as well, because they were no better.  It might not still be on sale, but plenty of forum readers still own and use the 5D2.

For anyone shooting with strobes, or shooting fast sports action in well lit areas, the 5D3 or 1DX is the camera you need (or perhaps a D800 at low ISO).

If you're shooting portraits with an f/1.4 lens, wide open at f/1.4, and require peripheral AF points to be used (for focusing on eyes, etc.), then yes the 6D will not give consistent results.  But then the 1DX and 5D3 don't fare much better in that situation, which is why serious portrait photogs who shoot this way, either manually focus, or use live view.  Of course most of them are closing that fast lens down quite a bit, in which case there is more wiggle room for AF inaccuracies.

And besides, in that peripheral area of these lenses (other than the Zeiss Otus)...those eyes that you claim are so razor sharp...actually are not, and are suffering from coma and astigmatism.  It's unavoidable...especially with such lenses as the 50L and 85L.

This was fine until you mentioned the 5D3 not being much better than the 6D for f/1.4 portraits using the outer AF points. The 5D3 makes the 6D look broken doing this and it's a shame a 60D or a 7D would also make the 6D look broken.

Pure opinion...

[CarlTN]

- The 6D's -3 EV lowlight sensitivity is currently unmatched by any DSLR on the market

If you shoot lowlight, sunsets, night photography or landscape photography the lowlight AF performance on the 6D wins.

As I pointed out a few pages ago in this thread:

How do you define 'low light'?  For example, the difference between shooting at -2 EV and-3 EV could mean 1/15 s, f/2.8, ISO 51200 vs. 102400.  Neither is very usable from an IQ standpoint.  What most people call 'low light' is generally substantially brighter than either spec.

Long exposure night photograpy might benefit from that extra stop of AF capability (but in that situation, you are on a triod and probably using Live View to focus anyway).  Sunsets, landscapes and general shooting have plenty of light relative to the AF sensitivity of even lower end dSLRs. 

I think the -3 EV spec of the 6D is Canon saying 'we did it because we can, and to throw a bone after otherwise limiting AF functionality of this body' - it looks good on paper, but is of little practical benefit in the vast majority of shooting situations.

As I've said many times, due to the low noise of the 6D, the low light sensitivity of the center AF point, can be very useful in the majority of situations where you are shooting wildlife (or people) around, before, or after sunset.  Or else if you are shooting landscape hand-held, with an IS lens, up to an hour after sunset...or during a full moon.  Or if you are shooting inside a club, or outside on a dimly lit city street at night, that -3EV capability is very useful.

ISO 6400 is extremely usable for professional prints via the 6D (with a bit of post processing), and ISO's a bit above that are still useful.

As for bashing the other AF points on the 6D, you need to bash the 5D2's as well, because they were no better.  It might not still be on sale, but plenty of forum readers still own and use the 5D2.

For anyone shooting with strobes, or shooting fast sports action in well lit areas, the 5D3 or 1DX is the camera you need (or perhaps a D800 at low ISO).

If you're shooting portraits with an f/1.4 lens, wide open at f/1.4, and require peripheral AF points to be used (for focusing on eyes, etc.), then yes the 6D will not give consistent results.  But then the 1DX and 5D3 don't fare much better in that situation, which is why serious portrait photogs who shoot this way, either manually focus, or use live view.  Of course most of them are closing that fast lens down quite a bit, in which case there is more wiggle room for AF inaccuracies.

And besides, in that peripheral area of these lenses (other than the Zeiss Otus)...those eyes that you claim are so razor sharp...actually are not, and are suffering from coma and astigmatism.  It's unavoidable...especially with such lenses as the 50L and 85L.

This was fine until you mentioned the 5D3 not being much better than the 6D for f/1.4 portraits using the outer AF points. The 5D3 makes the 6D look broken doing this and it's a shame a 60D or a 7D would also make the 6D look broken.

+1 with RLPhoto, I have no problem with outer AF points on my 5D III. Doesn't matter 85L II or 50L

Photo below was taken with 5D III + 50L, outer AF point @ f1.2. Oops...sorry, that was f1.2 not f1.4 as he mentioned

That's a chair, not someone's eyes.  Post one of those please.

[CarlTN]

If you're shooting portraits with an f/1.4 lens, wide open at f/1.4, and require peripheral AF points to be used (for focusing on eyes, etc.), then yes the 6D will not give consistent results.  But then the 1DX and 5D3 don't fare much better in that situation, which is why serious portrait photogs who shoot this way, either manually focus, or use live view.  Of course most of them are closing that fast lens down quite a bit, in which case there is more wiggle room for AF inaccuracies.

And besides, in that peripheral area of these lenses (other than the Zeiss Otus)...those eyes that you claim are so razor sharp...actually are not, and are suffering from coma and astigmatism.  It's unavoidable...especially with such lenses as the 50L and 85L.

This was fine until you mentioned the 5D3 not being much better than the 6D for f/1.4 portraits using the outer AF points. The 5D3 makes the 6D look broken doing this and it's a shame a 60D or a 7D would also make the 6D look broken.

+1

The 6D and a fast prime shot wide open are not a good combination - you either use a peripheral AF point and risk missing focus frequently (assuming there's even an AF point close to where you need it), or use the center point and recompose and guarantee backfocused shots.

As for sharp eyes with the 85L...

Show me the uncropped version, so I can see what part of the image this was cropped from.  And besides, this is soft...after criticizing me for posting soft images, this is rather amusing.  Post something SHARP, both cropped and uncropped, in the periphery...at f/1.4 or f/1.2.  Also make the eyes open, not closed please.

[CarlTN]

As I've said many times, due to the low noise of the 6D, the low light sensitivity of the center AF point, can be very useful in the majority of situations where you are shooting wildlife (or people) around, before, or after sunset.  Or else if you are shooting landscape hand-held, with an IS lens, up to an hour after sunset...or during a full moon.  Or if you are shooting inside a club, or outside on a dimly lit city street at night, that -3EV capability is very useful.

ISO 6400 is extremely usable for professional prints via the 6D (with a bit of post processing), and ISO's a bit above that are still useful.

ISO 6400 at -3 EV would be 1/4 s at f/1.4, 1 s at f/2.8.  Are you actually suggesting that such settings are, "useful in the majority of situations where you are shooting wildlife (or people) around, before, or after sunset??"  In that case, I would expect you'll have plenty of examples of wildlife that you shot at 1 s or longer exposures (unless you shoot a lot of wildlife with f/1.4 lenses) and people that you've shot at exposures of 1/4 s or longer, and you should be able to share several of them to support your contention.

Assuming 1/FL, a 24-28mm lens with 4-stop IS could be handheld at ~1/4 s (a conservative assumption, as with today's sensors 1/2xFL is more realistic).  That means your handheld landscape at -3 EV ISO 6400 would be at f/2.8 (and there are a few wide angle f/2.8 lenses with 4-stop IS/VC).  I'd be interested in seeing some examples of your landscapes shot at those settings, too, assuming you have any.

I've personally never shot landscapes/cityscapes at -3 EV unless on a tripod.  The shot below with the swan at the Palace of Fine Arts in San Francisco is the closest I've come to that handheld, it's 1/25 s, f/3.2 and ISO 12800, which is -1.3 EV.  There are issues with the shot - the DoF is too shallow so the structure is OOF, and the shutter speed wasn't quite fast enough to freeze the motion of the swimming swan; IS would not have helped (and at 17mm on a FF camera, IS isn't even a possibility).  The second shot below is an example of -3 EV - the only light sources in the room were the fireplace and the jack-o-lanterns, the settings were 1/15 s, f/2.8, ISO 102400.  In fact, I focused that shot through the viewfinder (although I could barely see), meaning the 1D X's AF was actually able to focus at -3 EV (although that's for the whole scene, the AF point was seeing more light than that).  Still, there's motion blur and lots of noise, and image is no more than a snapshot (albeit one not possible with most cameras).   

Considering the examples above, I would suggest that anyone arguing the -3 EV sensitivity of the 6D's AF system is an advantage over the -2 EV of the 5DIII or 1D X, or even the -0.5 EV sensitivity of most other bodies, in many situations, much less a majority of situations, doesn't know what they're talking about.

As I stated, the majority of situations which people call "low light" really offer plenty of light for the AF systems of even low-end dSLRs.  The extra one stop of sensitivity that the 6D has is an advantage only in very rare situations, so rare that many 6D users probably have not ever experienced them.

As for bashing the other AF points on the 6D, you need to bash the 5D2's as well, because they were no better.  It might not still be on sale, but plenty of forum readers still own and use the 5D2.

I agree, the outer AF points of the 5DII were not very useful, much like those of the 6D.  They did ok with high contrast subjects in bright light, but were lousy in dimmer light or for Servo tracking.

Your shot of the swan looks fine to me.  At least we can agree on something, regarding the outer AF points.  Sometimes they have trouble, other times not...but in low light they're definitely not very useful...especially with a faster aperture lens.  But that's obvious to anyone who has used the camera.

By the way, how long would you say, is the total number of minutes, you have spent with a 6D, in your life?  If that is a low number, why do you feel the need to comment on this camera so often?  Why don't you comment on the 1DX thread more?

I know you think I don't know what I'm talking about, and that's fine with me.  I could never prove you wrong about that, to yourself, no matter what I said or did.  You (and others) have a personal bias against me (and have since day one that I posted on here), so why would I waste my time trying to prove anything to you?  That would be pure folly...and I'm no fool.  However, I would suggest that someone who bullies people as much as you on a forum that is their personal sandbox to play in, is compensating for shortcomings.  I don't have those shortcomings...I don't come on here to compensate for anything.

I've shot about 14,000 shutter cycles with my 6D in a year.  If I don't know what I'm talking about, regarding it, how could that be?  I'm not perfect, but I know what I'm talking about.

How about this?  Since you enjoy commenting about the 6D so much on here, you should at least buy one and shoot it for a while (I would suggest daily for about 3 months at least), before asserting who knows what about the camera.  If that is an unreasonable suggestion, then I wonder who is really contributing on here in a meaningful way, and who is not?

At least one other poster has recently said they've used the 6D on the 50L and 85L, and to good effect.  I suppose he doesn't know what he's talking about either?  I asked him to share samples of his work, because I am slightly skeptical myself, but I don't think it's impossible to get decent results.  I approach things I have little or no experience with, with an open mind.  I don't make snap judgments based on very short experience, and then forever hold to such prejudice.  But that's one of the differences between you and me.  Another big difference, is I try to welcome newcomers with politeness...rather than snidely brow-beating them with trivia, as if this is some kind of robot war.  Nobody's perfect, but damn...??

[RLPhoto]

- The 6D's -3 EV lowlight sensitivity is currently unmatched by any DSLR on the market

If you shoot lowlight, sunsets, night photography or landscape photography the lowlight AF performance on the 6D wins.

As I pointed out a few pages ago in this thread:

How do you define 'low light'?  For example, the difference between shooting at -2 EV and-3 EV could mean 1/15 s, f/2.8, ISO 51200 vs. 102400.  Neither is very usable from an IQ standpoint.  What most people call 'low light' is generally substantially brighter than either spec.

Long exposure night photograpy might benefit from that extra stop of AF capability (but in that situation, you are on a triod and probably using Live View to focus anyway).  Sunsets, landscapes and general shooting have plenty of light relative to the AF sensitivity of even lower end dSLRs. 

I think the -3 EV spec of the 6D is Canon saying 'we did it because we can, and to throw a bone after otherwise limiting AF functionality of this body' - it looks good on paper, but is of little practical benefit in the vast majority of shooting situations.

As I've said many times, due to the low noise of the 6D, the low light sensitivity of the center AF point, can be very useful in the majority of situations where you are shooting wildlife (or people) around, before, or after sunset.  Or else if you are shooting landscape hand-held, with an IS lens, up to an hour after sunset...or during a full moon.  Or if you are shooting inside a club, or outside on a dimly lit city street at night, that -3EV capability is very useful.

ISO 6400 is extremely usable for professional prints via the 6D (with a bit of post processing), and ISO's a bit above that are still useful.

As for bashing the other AF points on the 6D, you need to bash the 5D2's as well, because they were no better.  It might not still be on sale, but plenty of forum readers still own and use the 5D2.

For anyone shooting with strobes, or shooting fast sports action in well lit areas, the 5D3 or 1DX is the camera you need (or perhaps a D800 at low ISO).

If you're shooting portraits with an f/1.4 lens, wide open at f/1.4, and require peripheral AF points to be used (for focusing on eyes, etc.), then yes the 6D will not give consistent results.  But then the 1DX and 5D3 don't fare much better in that situation, which is why serious portrait photogs who shoot this way, either manually focus, or use live view.  Of course most of them are closing that fast lens down quite a bit, in which case there is more wiggle room for AF inaccuracies.

And besides, in that peripheral area of these lenses (other than the Zeiss Otus)...those eyes that you claim are so razor sharp...actually are not, and are suffering from coma and astigmatism.  It's unavoidable...especially with such lenses as the 50L and 85L.

This was fine until you mentioned the 5D3 not being much better than the 6D for f/1.4 portraits using the outer AF points. The 5D3 makes the 6D look broken doing this and it's a shame a 60D or a 7D would also make the 6D look broken.

Pure opinion...

Pure denial...

[Sporgon]

The outer points on both the 5DII and 6D are perfectably fine in reasonable light and with contrast in the appropriate orientation. But defending them against the likes of the 1D series and now III version of the 5D is pretty pointless. I'm only really familiar with the 1D IIn, but the way that camera nailed focus anywhere made the 5D seem as if it had come out of the Ark. Unfortunately ( or fortunately depending on my sanity) I appreciate that you get what you pay for, but good for Canon putting the majority of it's flagship system in the 5DIII.

However, from what I read, the D600/610 isn't in the 1D /5DIII class of AF anyway despite having loads of x points etc. Nor are the likes of the top end Rebels.

The 6D is a perfectly fine camera but I doubt it will ever satisfy those who wanted a 5DIII at 6D prices.

[candyman]

..............
The 6D is a perfectly fine camera but I doubt it will ever satisfy those who wanted a 5DIII at 6D prices.

True. You can't have 5D MKIII for a 6D price
I bought my 6D because I wanted a 2nd camera for use of portrait, landscape and walk-around camera. It is a great camera for that. I sold my 7D and bought the 6D because I wanted to have IQ on par with my 5D MKIII.

[Dylan777]

- The 6D's -3 EV lowlight sensitivity is currently unmatched by any DSLR on the market

If you shoot lowlight, sunsets, night photography or landscape photography the lowlight AF performance on the 6D wins.

As I pointed out a few pages ago in this thread:

How do you define 'low light'?  For example, the difference between shooting at -2 EV and-3 EV could mean 1/15 s, f/2.8, ISO 51200 vs. 102400.  Neither is very usable from an IQ standpoint.  What most people call 'low light' is generally substantially brighter than either spec.

Long exposure night photograpy might benefit from that extra stop of AF capability (but in that situation, you are on a triod and probably using Live View to focus anyway).  Sunsets, landscapes and general shooting have plenty of light relative to the AF sensitivity of even lower end dSLRs. 

I think the -3 EV spec of the 6D is Canon saying 'we did it because we can, and to throw a bone after otherwise limiting AF functionality of this body' - it looks good on paper, but is of little practical benefit in the vast majority of shooting situations.

As I've said many times, due to the low noise of the 6D, the low light sensitivity of the center AF point, can be very useful in the majority of situations where you are shooting wildlife (or people) around, before, or after sunset.  Or else if you are shooting landscape hand-held, with an IS lens, up to an hour after sunset...or during a full moon.  Or if you are shooting inside a club, or outside on a dimly lit city street at night, that -3EV capability is very useful.

ISO 6400 is extremely usable for professional prints via the 6D (with a bit of post processing), and ISO's a bit above that are still useful.

As for bashing the other AF points on the 6D, you need to bash the 5D2's as well, because they were no better.  It might not still be on sale, but plenty of forum readers still own and use the 5D2.

For anyone shooting with strobes, or shooting fast sports action in well lit areas, the 5D3 or 1DX is the camera you need (or perhaps a D800 at low ISO).

If you're shooting portraits with an f/1.4 lens, wide open at f/1.4, and require peripheral AF points to be used (for focusing on eyes, etc.), then yes the 6D will not give consistent results.  But then the 1DX and 5D3 don't fare much better in that situation, which is why serious portrait photogs who shoot this way, either manually focus, or use live view.  Of course most of them are closing that fast lens down quite a bit, in which case there is more wiggle room for AF inaccuracies.

And besides, in that peripheral area of these lenses (other than the Zeiss Otus)...those eyes that you claim are so razor sharp...actually are not, and are suffering from coma and astigmatism.  It's unavoidable...especially with such lenses as the 50L and 85L.

This was fine until you mentioned the 5D3 not being much better than the 6D for f/1.4 portraits using the outer AF points. The 5D3 makes the 6D look broken doing this and it's a shame a 60D or a 7D would also make the 6D look broken.

+1 with RLPhoto, I have no problem with outer AF points on my 5D III. Doesn't matter 85L II or 50L

Photo below was taken with 5D III + 50L, outer AF point @ f1.2. Oops...sorry, that was f1.2 not f1.4 as he mentioned

That's a chair, not someone's eyes.  Post one of those please.

A lot of thing to say...little to show

1st photo SOOC, untouch: 5D III + 85L II, 1/160 @ f1.2, outer AF point, was focus on her left eye
2nd little edit in LR

BTW, I have no problem using AF in -3EV lighting condition, yes, with 5D III. Wanna see sample photos?

[neuroanatomist]

By the way, how long would you say, is the total number of minutes, you have spent with a 6D, in your life?  If that is a low number, why do you feel the need to comment on this camera so often?  Why don't you comment on the 1DX thread more?

A sufficient number.  In fact, I don't comment with great frequency on the 6D relative to other cameras.  I think you just pay more attention to comments on the 6D – especially negative comments (and more so when you're wearing your SuperCarl cape and tights). I comment frequently on the 1D X.  There are simply more threads on the 5DIII and 6D because those bodies are within budget for many more people.

How about this?  Since you enjoy commenting about the 6D so much on here, you should at least buy one and shoot it for a while (I would suggest daily for about 3 months at least), before asserting who knows what about the camera. 

If you had five acres of grass to mow, would you trade your riding mower for a hand-pushed mower, just to prove to yourself that the riding mower was better?  I wouldn't...  Yes, the push mower can be better in very limited situations, like a narrow strip of grass between two structures.  In the same way, there are rare situations where the 6D is better than the higher-end models. 

I know you think I don't know what I'm talking about, and that's fine with me.  I could never prove you wrong about that, to yourself, no matter what I said or did.  You (and others) have a personal bias against me (and have since day one that I posted on here), so why would I waste my time trying to prove anything to you?  That would be pure folly...and I'm no fool.

I have a bias against misinformation.  You stated that the -3 EV AF sensitivity of the 6D, "...can be very useful in the majority of situations where you are shooting wildlife (or people) around, before, or after sunset."  When challenged to back up that claim, instead of even a single image representing 'the majority' you respond with justifications and excuses.

Yes, the 6D can focus well in moderately dim light, as long as you're only using the center point.  In equally dim light, the 5DIII and 1D X can focus just as well with many more AF points, notably with off-center cross-type AF points.  The 6D has no advantage in lighting that allows usable images in most situations, particularly in the situations to which you refer.  The expression, "Put up or shut up," comes to mind.

However, I would suggest that someone who bullies people as much as you on a forum that is their personal sandbox to play in, is compensating for shortcomings.  I don't have those shortcomings...I don't come on here to compensate for anything.

I approach things I have little or no experience with, with an open mind.  I don't make snap judgments based on very short experience, and then forever hold to such prejudice.  But that's one of the differences between you and me.  Another big difference, is I try to welcome newcomers with politeness...rather than snidely brow-beating them with trivia, as if this is some kind of robot war.  Nobody's perfect, but damn...??

If this is a sandbox, you started out by pissing in it.  Within a few days of your first post, you had offended and/or drawn the ire of several forum members (myself not included, yet).

Less than a month after joining, you replied to someone with this:

I'll put mine up against yours any day of the week young lad.  Whoever's lens loses, has to buy the winner a chess set made of all the Nikon and Canon supertelephoto lenses...oh, and we exchange wives and/or girlfriends...and mistresses, for a month...yours won't be coming home after they've played chess with me!  If I lose...well...I keep my harem chained in an underground lair out in the woods...they aren't really allowed to leave...but I'll send you my neighbor's wife.

Frankly, a comment like that is beyond merely offensive, it's disgusting and repugnant.  Any "man" who would make a statement like that, even attempting to pass it off as humor, is clearly compensating for a whole host of shortcomings. 

Nobody's perfect, but most of us aren't sociopathic. 

[CarlTN]

As I stated, the majority of situations which people call "low light" really offer plenty of light for the AF systems of even low-end dSLRs.  The extra one stop of sensitivity that the 6D has is an advantage only in very rare situations, so rare that many 6D users probably have not ever experienced them.

Having shot with the 6d and my 70-300L I changed my opinion and would disagree here:

The 6d still af's in dim light @f5.6 aperture just fine w/o af assist, and the exposure was taken care of with some flashes and iso 6400. For the big boys with constant f2.8 zooms pr even faster primes that might not matter that much, but for the cheap rest of us 1 more stop of af capability can come in handy

Nice to see you weigh in here.