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

[CarlTN]

I got the 6D for about one year now.
The least description of 6D that makes me happy "owning" it is that:

"The 6D is better than 5Dii in about every aspect."
And 5Dii have took a lot of great pictures.

Just sharing what I thought about the AF of my 6D.
Im very amateur and shoot still people.
And I really dont check and compare if focus was spot on.
At decent light like normal house room with fluorescent lighting or sunlight outside or soft light outdoor.
Outer focus points works.

I am happy with 6D Outer point AF, can't say much.

Glad to hear you like yours! Yes in that light the outer points work, they just aren't reliable in servo mode. It really also depends on the lens. There were plenty of people who complained about the 5D2 autofocus. It's just that they had to either buy it, or the 1Ds3...or the D700. The D700 was probably the more capable stills camera. It just didn't have the resolution (at low ISO), and was from the wrong company...had the wrong ergonomics...I could go on.

 

[J.R.]

How about a handheld shot indoors in a dark room at 300mm and f/5.6 (with the 70-300L), for .8 seconds at ISO 10,000? Is that not low light? If a 5D3 can autofocus in that amount of light, I'll go buy 10 of them tomorrow...

Those settings would result in close to EV +1. The AF working range of the 5D3 is between EV (-) 2 to (+) 18 so yeah ... it will autofocus.

 

[Marsu42]

How about a handheld shot indoors in a dark room at 300mm and f/5.6 (with the 70-300L), for .8 seconds at ISO 10,000? Is that not low light? If a 5D3 can autofocus in that amount of light, I'll go buy 10 of them tomorrow...

Those settings would result in close to EV +1. The AF working range of the 5D3 is between EV (-) 2 to (+) 18 so yeah ... it will autofocus.

Thanks for the calculation, imho Canon pulled a real marketing stunt with the -3LV af as the 6d defining feature since it's only the center point, and very few people will need this one stop more, ever.

For me it's still useful for silently af'ing animals in very dark conditions w/o af assist for flash shots, and neuro has convinced me that there might be some long expo handheld shots with IS that are -3LV. For tripod shots I'D still take live view focusing with ML focus peaking and "night mode" lv boost over phase af...

 

[candc]

How about a handheld shot indoors in a dark room at 300mm and f/5.6 (with the 70-300L), for .8 seconds at ISO 10,000? Is that not low light? If a 5D3 can autofocus in that amount of light, I'll go buy 10 of them tomorrow...

10 of them, thats 610 af points, Dang!

the 6d af does what its supposed to but like the rest of the camera, its not real exciting. it needs some cool sounding features like "dual pixel auto focus". dual anything sounds awesome, dual rectifier, dual exhaust. maybe next one will get a dual core digic+ image processor, now that sounds cool.

 

[Loswr]

How about a handheld shot indoors in a dark room at 300mm and f/5.6 (with the 70-300L), for .8 seconds at ISO 10,000? Is that not low light? If a 5D3 can autofocus in that amount of light, I'll go buy 10 of them tomorrow...

Those settings would result in close to EV +1. The AF working range of the 5D3 is between EV (-) 2 to (+) 18 so yeah ... it will autofocus.

Actually, by accepted convention those settings are EV –1.67, which is above the specified EV –2 sensitivity of the 5DIII. I have empirically confirmed that my 1D X (same AF sensor as the 5DIII) can AF at those light levels.

Carl, I look forward to tomorrow when you post a scanned image of the receipt or invoice for the 10 5DIII bodies you're going to buy. Unless you were not being honest... Of course, I would not find that surprising – it seems commensurate with your rudeness and insulting behavior.

 

[Marsu42]

maybe next one will get a dual core digic+ image processor, now that sounds cool.

Actually the last one might be useful, more capable cameras have a second processor for autofocus - and on the 6d when enabling multipoint tracking, the struggle of the camera to decide where to focus is pitiful. But then again, the 60d did better with an even slower digic4, so the 6d firmware might as well to blame.

Carl, I look forward to tomorrow when you post a scanned image of the receipt or invoice for the 10 5DIII bodies you're going to buy.

Oh, come on, don't be so hard on him - you known he's doesn't know what he's talking about when it comes to the 6d (though he has a refreshingly stern opinion based on that)... and everybody is entitled to a little enthusiasm. Maybe he can get off the 10x 5d3 purchase if he pledges to learn about the "Insert Quote" and "Edit Post" buttons so he doesn't have to do 5 separate posts with complete quotes in succession ?

 

[Chuck Alaimo]

Half a year now on my 6d, and running side by side with a 5d3. I shoot mostly weddings and portraits, with some events splashed in. I have to say for all the talk about the 6d's lacking AF, it's really not that bad. I am not shooting sports though or high action - so the weakness (servo mode) isn't a deal breaker for me. But with that said, it can get the job done... (lol...if you have to drive a nail in and only have a screw driver, you can get the nail in, yeah a hammer is the correct tool, but, you can still bang it in there with the butt end...)

The outer points, for stills, are usable in the right situations (and if its dark, the AF assist beam from a flash can make up the difference).

It's really not a bad camera!

 

[Skirball]

How about a handheld shot indoors in a dark room at 300mm and f/5.6 (with the 70-300L), for .8 seconds at ISO 10,000? Is that not low light? If a 5D3 can autofocus in that amount of light, I'll go buy 10 of them tomorrow...

You can handhold at 300mm for .8 seconds? I guess I don't have a steady grip.

Not to get in yet another one of your pissing matches, but I do find the low light centerpoint to be useful when shooting in a dark room with off-camera flash.

 

[Marsu42]

You can handhold at 300mm for .8 seconds? I guess I don't have a steady grip.

Nobody can do that without a large amount of luck, not even our unofficial 6d ambassador, but you're thinking of 100% crop sharpness - if you're shooting for a small print/viewing size a bit shaky shot is better than one completely out of focus.

but I do find the low light centerpoint to be useful when shooting in a dark room with off-camera flash.

+1, and I'm also using the low-light af with a flash on a bracket - but it's slow, that's why I'll most likely get the new Yn radio trigger with built-in af assist.

 

[YuengLinger]

"One thing the 60D DOES NOT HAVE, and one thing both the 6D and 50D have...is autofocus micro adjustment. The 6D even has it for both the wide and tele ends of a zoom lens."

Agreed, lack of micro adjustment is a deficiency of the 60D. But the point is that the lowly 60D has an all around more robust, quicker AF for those of us who want more than one AF point dead in the center. I've used it in a lot of situations, low light, birds in flight, landscape--always super reliable, quick AF at any point.

(In fact, I guess I was lucky with the lenses on my 60D, as they were all sharp, even my ef 50mm 1.4.

On my 5DIII, only two lenses need AF micro adjust--my 100mm 2.8 macro (standard) and my Sigma 35mm 1.4. My zooms are all great.)

Anyway, AF micro adjust is for another thread, but it is undeniably an important feature and a "pro" for the 6D.

Happy holidays, all!

 

[CarlTN]

How about a handheld shot indoors in a dark room at 300mm and f/5.6 (with the 70-300L), for .8 seconds at ISO 10,000? Is that not low light? If a 5D3 can autofocus in that amount of light, I'll go buy 10 of them tomorrow...

Those settings would result in close to EV +1. The AF working range of the 5D3 is between EV (-) 2 to (+) 18 so yeah ... it will autofocus.

Correct, because I wanted the image to look like the lights were on, even though they were off. So I used positive exposure compensation.

 

[CarlTN]

How about a handheld shot indoors in a dark room at 300mm and f/5.6 (with the 70-300L), for .8 seconds at ISO 10,000? Is that not low light? If a 5D3 can autofocus in that amount of light, I'll go buy 10 of them tomorrow...

Those settings would result in close to EV +1. The AF working range of the 5D3 is between EV (-) 2 to (+) 18 so yeah ... it will autofocus.

Thanks for the calculation, imho Canon pulled a real marketing stunt with the -3LV af as the 6d defining feature since it's only the center point, and very few people will need this one stop more, ever.

For me it's still useful for silently af'ing animals in very dark conditions w/o af assist for flash shots, and neuro has convinced me that there might be some long expo handheld shots with IS that are -3LV. For tripod shots I'D still take live view focusing with ML focus peaking and "night mode" lv boost over phase af...

As I explained above, I used positive exposure compensation. So yeah, the actual available light was more like -2 to -3EV. And this was with a lens that was native f/5.6. The room was quite dark.

 

[CarlTN]

Correct, because I wanted the image to look like the lights were on, even though they were off. So I used positive exposure compensation.

Now just wait here - you're saying that the light level was -2 LV, but with setting +1 positive exposure compensation on your camera you dimmed down the ambient to -3 LV so that only the 6d af would have been able to auto-focus as you theorized with the wager of buying 10 5d3 camera bodies?

Look, you all can calculate the available light all you like. I don't have a calibrated light meter. It was a black pepper shaker that I focused on with that center point. I just looked it up in my camera, and the exposure compensation was +2 EV. I will post the picture in the next day or two, unedited, but also post an edited version to make the darkness appear how it looked to my eye. I shot it as a jpeg. There is white lettering against the black of the shaker that says "pepper", that helped the autofocus. Also there is a highlight on the left edge of the shaker, but I didn't put the point over that. It may or may not have been a factor in the focusing. I was mainly trying to test the IS...it worked, but only for about 1 in 4 of the shots at such a long exposure. How many stops of IS is 8/10 of a second at 300mm?

 

[J.R.]

How about a handheld shot indoors in a dark room at 300mm and f/5.6 (with the 70-300L), for .8 seconds at ISO 10,000? Is that not low light? If a 5D3 can autofocus in that amount of light, I'll go buy 10 of them tomorrow...

Those settings would result in close to EV +1. The AF working range of the 5D3 is between EV (-) 2 to (+) 18 so yeah ... it will autofocus.

Correct, because I wanted the image to look like the lights were on, even though they were off. So I used positive exposure compensation.

I'm not sure I understand your post.

 

[Marsu42]

It may or may not have been a factor in the focusing. I was mainly trying to test the IS...it worked, but only for about 1 in 4 of the shots at such a long exposure. How many stops of IS is 8/10 of a second at 300mm?

Sorry, I mis-read your posts (just drinking my morning coffee ) and removed it, but not before you could snatch it for a quote ... you're correct, with exposure compensation used (which you didn't mention at the time) you cannot directly calculate back the ambient from only shutter/aperture/iso, so if it was as you said it might have been darker than -2 LV.

Another question is how hard these barriers are, much more likely the camera's ability to af doesn't stop suddenly af -3.000001 LV, and nobody really tested it so we can only take Canon's word on how large the 5d3/6d gap really is.

My experience with the 6d af using the 100L f2.8(!) lens is that the lack of a precise center cross point shows up more at dim light, it af's alright sooner or later, but the precision seems to be worse than at good light unless you're extra-careful to pick a contrast part. With a f4+ lens you won't have these troubles of course.

 

[CarlTN]

It may or may not have been a factor in the focusing. I was mainly trying to test the IS...it worked, but only for about 1 in 4 of the shots at such a long exposure. How many stops of IS is 8/10 of a second at 300mm?

Sorry, I mis-read your posts (just drinking my morning coffee ) and removed it, but not before you could snatch it for a quote ... you're correct, with exposure compensation used (which you didn't mention at the time) you cannot directly calculate back the ambient from only shutter/aperture/iso, so if it was as you said it might have been darker than -2 LV.

Another question is how hard these barriers are, much more likely the camera's ability to af doesn't stop suddenly af -3.000001 LV, and nobody really tested it so we can only take Canon's word on how large the 5d3/6d gap really is.

My experience with the 6d af using the 100L f2.8(!) lens is that the lack of a precise center cross point shows up more at dim light, it af's alright sooner or later, but the precision seems to be worse than at good light unless you're extra-careful to pick a contrast part. With a f4+ lens you won't have these troubles of course.

Something we can agree on! I have the same experience as you with your 100 f/2.8, in my same darkly lit room, with my 135 f/2 mounted. It absolutely refuses to autofocus with just center point, where it will easily AF with an f/4 lens in the same light. An f/4 lens is how much less light than f/2?

As for the 70-300L, I really must conclude that it just still can't autofocus as fast or in as low of a light, as the 70-200 f/4 (non IS)...even if the 70-300L is zoomed to f/4 at the wider end. The 70-300L has more trouble all around than the 70-200 f/4. I hate to sell it, but I can't afford to keep both lenses (also need to sell two of my Sigma lenses...I like them but I can't afford to collect 40 lenses like some of you guys).

The 70-200 f/4 non-IS, combined with the 6D, absolutely got the best out of the 6D's admittedly limited autofocus and servo tracking ability, in my experience. I've still not fully explored the 70-300L's servo ability, but given its single shot performance, I have to conclude it also cannot do what the 70-200 f/4 could do.

The 70-300L seems quite a lot sharper, except all the way at 300mm. It seems to have slightly more CA, but it's not a problem. It seems to have quite a lot more contrast (similar to the 135 f/2 and that's saying something, especially for a zoom!!)...And again, it most definitely is the most flare resistant lens I've ever used. The reviews that talk about this are almost understating it. I can't believe I'm pointing this thing nearly into the sun and no flare, no significant hazing (ghosting?).

The IS of the 70-300L can be spectacular (.8 seconds hand-held at 300mm)...but this is NOT the norm. And if I focus-recompose and I'm not in panning mode, the IS gets upset and I have to let it settle for probably 1.5 seconds before I snap the picture. It does seem to have some mirror slap compensation (which is impressive in itself at this price level imho)...But again, it's nothing like the best IS I've personally experienced so far, the 200 f/2L. That was in another realm...however the 200L's IS was probably only reliably repeatable while hand-held at 1/10 or 1/13 of a second, and faster. The 70-300L is similar at 1/30 or 1/40 of a second...at least at 300mm. In the middle, around 100-150mm, it might be repeatable down to 1/20 second. At the wide end it seems slightly better than the long end, but not as good as from 100-150mm.

 

[Marsu42]

I've still not fully explored the 70-300L's servo ability, but given its single shot performance, I have to conclude it also cannot do what the 70-200 f/4 could do.

I've already read multiple posts complaining about 6d+70-300L, but I have to say I can't see the problem - but maybe that's because I've only got "tricky" lenses to begin with and no good "standard" comparison. Unless I use multipoint-tracking in which the result is pitiful, the 70-300L is ok at single-point tracking, well, as ok as I'd expect the 6d to get at all.

The one issue I can see that the 70-300L exposes the 6d not to be a closed loop system. I just tested it in a dim room, it af's a first step, then thinks again for some microseconds, then af's a second step - just like the Tamron 24-70/2.8 does. I also just did a quick comparison on the 60d: the speed isn't a big difference, however the final 2nd af step seems to be bit faster on the 60d, but it's also there.

 

[CarlTN]

I've still not fully explored the 70-300L's servo ability, but given its single shot performance, I have to conclude it also cannot do what the 70-200 f/4 could do.

I've already read multiple posts complaining about 6d+70-300L, but I have to say I can't see the problem - but maybe that's because I've only got "tricky" lenses to begin with and no good "standard" comparison. Unless I use multipoint-tracking in which the result is pitiful, the 70-300L is ok at single-point tracking, well, as ok as I'd expect the 6d to get at all.

The one issue I can see that the 70-300L exposes the 6d not to be a closed loop system. I just tested it in a dim room, it af's a first step, then thinks again for some microseconds, then af's a second step - just like the Tamron 24-70/2.8 does. I also just did a quick comparison on the 60d: the speed isn't a big difference, however the final 2nd af step seems to be bit faster on the 60d, but it's also there.

Interesting, I've not noticed a two step process.

 

[Marsu42]

Interesting, I've not noticed a two step process.

Compare it to a "closed loop" system like 1dx/5d3 if you have the opportunity, these don't need any further feedback from the lens and can tell it precisely where to focus in one step, while "open loop" systems use a second micro-step depending on circumstances. This is the big advantage of Canon's newest af system, though it only works in combination with the latest lenses.

 

[CarlTN]

Interesting, I've not noticed a two step process.

Compare it to a "closed loop" system like 1dx/5d3 if you have the opportunity, these don't need any further feedback from the lens and can tell it precisely where to focus in one step, while "open loop" systems use a second micro-step depending on circumstances. This is the big advantage of Canon's newest af system, though it only works in combination with the latest lenses.

My cousin who owns the 1DX does not have any of the newest lenses. You're welcome to bring all of yours over sometime!