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

[3kramd5]

The lateral points are vertical line sensors, meaning they detect horizontal lines

Ah yes, pardon the brain fart.

 

[Ruined]

I have both the 6D as well as the 5D3. I've tried and did not like using the 50L or the 85L II on the 6D except when I was shooting with a tripod and LV. The positioning of the AF points on the 6D is such that lots of focus-recompose is needed and with the 50L and 85L II, it's just asking for trouble.

While it is true you are more limited with your AF points on the 6D, keep in mind you can focus and crop instead of recompose.

More importantly, the 6D allows for easy switch to Eg-S focus screen unlike the 5D3 - so IMO 6D actually has a significant advantage for manually focusing the f/1.2 lenses and seeing their true DOF in the viewfinder. One could argue you are looking for trouble in general if you try to autofocus at f/1.2 all the time no matter what camera you use.

 

[J.R.]

While it is true you are more limited with your AF points on the 6D, keep in mind you can focus and crop instead of recompose.

Certainly, but I'd consider it a a workaround in the extreme.

More importantly, the 6D allows for easy switch to Eg-S focus screen unlike the 5D3 - so IMO 6D actually has a significant advantage for manually focusing the f/1.2 lenses and seeing their true DOF in the viewfinder.

Yes, the focusing screen can be installed (I have the Eg-S screen) but I'm specifically commenting on the AF which doesn't work too well with very large aperture lenses. Comparing the 5D3 AF with the 6D MF with Eg-S screen is like comparing apples to oranges. The 5D3 outer AF points will lock on with superb precision and you would have already taken the shot and moved on to another in the same time you would be focusing manually with the 6D.

One could argue you are looking for trouble in general if you try to autofocus at f/1.2 all the time no matter what camera you use.

All EOS cameras AF with the lenses wide open, so a f/1.2 lens will AF wide open at f/1.2 no matter what settings you use to shoot. The cross type outer AF points work extremely well on the 5D3. See below photo taken with a 5D3 with 85L II - 100% crop of the AF area also provided - I have been using this combo for quite a while now and am happy with the results.

Not saying that 6D is a bad camera, but the whinging that takes place over the AF happens deservedly so.

Edit: I'm not sure how to post the 100% crop. The 100% crop image that I can view here on CR is larger than what I see in LR with a 1:1 view - any tips on how to post the exact image?

 

[CarlTN]

I have both the 6D as well as the 5D3. I've tried and did not like using the 50L or the 85L II on the 6D except when I was shooting with a tripod and LV. The positioning of the AF points on the 6D is such that lots of focus-recompose is needed and with the 50L and 85L II, it's just asking for trouble.

Strange as it may sound, the 135L doesn't give me nearly half as much trouble - and yes, I AFMA all my lenses using FoCal.

OTOH, I hardly ever face trouble with the outer focus points on the 5D3 - it is pointless comparing the AF systems on both cameras. The 6D isn't built for fast action shooting - you may be able to get some shots in focus, but the chances of an OOF shot are higher.

True enough. I've not tried either the 50L or 85L on my 6D, yet. My 135L actually gives more AF trouble than all f/4 aperture zoom lenses I've owned or used on it, which I have stated before. This is the nature of the 6D AF sensor. The 85L that I rented 4 years ago, certainly would not AF accurately on my 50D no matter what I did with the AFMA. When in an earlier post above, I said the 5D3 "didn't fare much better" with its outer AF points, I should have said it another way...certainly the 6D's outer points don't compare, and I didn't mean to imply they did. I experimented with selecting the outer right side AF point this morning, in servo mode with just my 24-105 at 105mm. It got about 7 shots out of 10 usably sharp, but only 6 out of 10 were critically sharp (the shutter speed was only 1/320 in Tv mode, though...but the light was less than ideal). This was on a stationary object backlit in a window sill, as I walked toward it while shooting the camera at 4.5 fps. If this had been a native f/1.2 lens, I have no idea what the "sharp" focus rate would be, but I suspect 3 to 4 out of 10 at best. Again though, those are portrait lenses, not sports lenses, so...neither the camera (6D) nor the lens, is designed to work ideally in servo AF mode anyway. Mating the two together, is not going to be reliable. Some say it's usable with still portrait shooting, and that is what I would like to see.

 

[CarlTN]

Are you Dylan? That quote was from his post.

I thought you were discussing side AF points. Those eyes look pretty centered in the FOV to me, unless this is heavily cropped...which I doubt.

 

[CarlTN]

Not saying that 6D is a bad camera, but the whinging that takes place over the AF happens deservedly so.

While I see where you are coming from, I disagree. The 6D does not deserve the criticism it gets regarding its AF. Why? Mostly because most of the same folks who are bashing its AF, spent 5 years thinking their 5D2 was a superb camera at a superb price, and rarely complained, if EVER, about its AF performance. The 6D proves you can get a better camera overall for $1000 less than the 5D2 sold for over most of its life. So the 6D definitely does not deserve criticism that is really just nitpicking and kicking the next lower model down from the one you like best.

It's only since Canon decided to gift the 5D3 with the 1DX AF sensor, that you suddenly have people saying the 6D has "terrible" AF performance. It most definitely is not "terrible". What it is, is "quite usable". If the successor to the 6D gets the 1DX AF sensor, and sells for the same or lower price than the current 6D...ONLY THEN can you say the 6D had a "terrible AF sensor" for the money. Because as of now, it does not.

While your image of the girl looks sharp, all I can say is, her nose occupies the right side of the "center 50%" of the image. My previous point, had to do with the nasties that come about when you go outside that 50%, with an f/1.2 lens, shot at f/1.2. I thought the side AF points of the 5D3, were well outside this center 50% image area. In fact I'm pretty sure they are. The 6D's side point is almost at this location...but would be closer to her ear ring...hardly a matter of much focus and recompose.

 

[CarlTN]

I have both the 6D as well as the 5D3. I've tried and did not like using the 50L or the 85L II on the 6D except when I was shooting with a tripod and LV. The positioning of the AF points on the 6D is such that lots of focus-recompose is needed and with the 50L and 85L II, it's just asking for trouble.

While it is true you are more limited with your AF points on the 6D, keep in mind you can focus and crop instead of recompose.

More importantly, the 6D allows for easy switch to Eg-S focus screen unlike the 5D3 - so IMO 6D actually has a significant advantage for manually focusing the f/1.2 lenses and seeing their true DOF in the viewfinder. One could argue you are looking for trouble in general if you try to autofocus at f/1.2 all the time no matter what camera you use.

Indeed.

 

[CarlTN]

And let the record show that I replied to neuro, but it got deleted. Like that's never happened before, lol!

 

[Loswr]

Mostly because most of the same folks who are bashing its AF, spent 5 years thinking their 5D2 was a superb camera at a superb price, and rarely complained, if EVER, about its AF performance.

That's some serious revisionist history. Complaints and bashing on the 5DII's AF are legion. The original 5D's AF system was often likened to the 20D, and there was major flak from the beginning when the 5DII came out with the same AF.

For example, this from just after its release: http://blog.kareldonk.com/canon-eos-5d-mark-ii-not-all-it-could-have-been/

I think the 6D suffers even more from the backlash of having an AF system not significantly better than that of the original 5D, and that backlash is made even worse by the stellar AF put into the 5DIII.

Yes, the 5DII's AF had a few defenders, as does the 6D's. Some of those defenders have even achieved superhero status:

But most of the defenses come off as apologies - 'the 5DII's AF isn't bad considering the image sensor is the same as the flagship 1DsIII' and 'the 6D is great for the price'. Both statements are true, but the fact remains that the old 40D had a better AF sensor than the 5D/5DII/6D, and the 40D's AF sensor has now trickled down into the Rebel/xxxD line, while the 7D and 70D have an AF sensor that's far better than those in the lower end FF bodies.

 

[CarlTN]

Mostly because most of the same folks who are bashing its AF, spent 5 years thinking their 5D2 was a superb camera at a superb price, and rarely complained, if EVER, about its AF performance.

That's some serious revisionist history. Complaints and bashing on the 5DII's AF are legion. The original 5D's AF system was often likened to the 20D, and there was major flak from the beginning when the 5DII came out with the same AF.

For example, this from just after its release: http://blog.kareldonk.com/canon-eos-5d-mark-ii-not-all-it-could-have-been/

I think the 6D suffers even more from the backlash of having an AF system not significantly better than that of the original 5D, and that backlash is made even worse by the stellar AF put into the 5DIII.

But most of the defenses come off as apologies - 'the 5DII's AF isn't bad considering the image sensor is the same as the flagship 1DsIII' and 'the 6D is great for the price'. Both statements are true, but the fact remains that the old 40D had a better AF sensor than the 5D/5DII/6D, and the 40D's AF sensor has now trickled down into the Rebel/xxxD line, while the 7D and 70D have an AF sensor that's far better than those in the lower end FF bodies.

Well your history is different from mine. I'm not revising anything, I'll leave that to you and your little helpers.

All I ever read, was how great the 5D2 was. And the people I knew who owned it, thought it was the best camera ever made.

Not sure what other backlash you are talking about of the 6D, besides its AF sensor.

 

[J.R.]

While your image of the girl looks sharp, all I can say is, her nose occupies the right side of the "center 50%" of the image. My previous point, had to do with the nasties that come about when you go outside that 50%, with an f/1.2 lens, shot at f/1.2. I thought the side AF points of the 5D3, were well outside this center 50% image area. In fact I'm pretty sure they are. The 6D's side point is almost at this location...but would be closer to her ear ring...hardly a matter of much focus and recompose.

Not sure what you mean. The focus was on her left eye with the outer AF points

 

[CarlTN]

While your image of the girl looks sharp, all I can say is, her nose occupies the right side of the "center 50%" of the image. My previous point, had to do with the nasties that come about when you go outside that 50%, with an f/1.2 lens, shot at f/1.2. I thought the side AF points of the 5D3, were well outside this center 50% image area. In fact I'm pretty sure they are. The 6D's side point is almost at this location...but would be closer to her ear ring...hardly a matter of much focus and recompose.

Not sure what you mean. The focus was on her left eye with the outer AF points

I'm saying my previous point had to do with the part of the FOV that was even farther outside this area. I thought the width of the AF sensor area in the FOV of the 5D3, was wider than that.

 

[Dick]

I have both the 6D as well as the 5D3. I've tried and did not like using the 50L or the 85L II on the 6D except when I was shooting with a tripod and LV. The positioning of the AF points on the 6D is such that lots of focus-recompose is needed and with the 50L and 85L II, it's just asking for trouble.

While it is true you are more limited with your AF points on the 6D, keep in mind you can focus and crop instead of recompose.

Focusing to the center and then cropping off half of the photo? In that case I'd rather use a crop body with a decent AF system.

 

[CarlTN]

Full size uncropped image. Autofocused with the 6D center point on the yellow bubble level, then recomposed. Apparently nobody else can do this, but my camera can while I'm bending over, and handholding it in a very dark room, at 1/13 second, f/1.8, 24mm, about 4 inches from the lens front element, with no image stabilization. It looked darker than this to my naked eye, and I don't think I used exposure compensation (the metadata doesn't show it if I did). Shot only as a jpeg, with some NR applied in LR. ISO 25,600.

What's all the fuss about focusing and recomposing? If little old me can do this, hand-held with no image stabilization, why can't others do it at 1/200 second in good light, or especially with strobes or flashguns? Not saying all lenses and focal lengths are the same...but gee whiz. It's not unheard of, because I did it.

 

[Ruined]

While it is true you are more limited with your AF points on the 6D, keep in mind you can focus and crop instead of recompose.

Certainly, but I'd consider it a a workaround in the extreme.

Well, considering that the 5D3 AF points definitely are far from filling the entire frame, it is a workaround you will have to employ on the 5D3 as well - perhaps just less frequently. At f/1.2, one should never focus and recompose even a smidgen as you well know due to the thin DOF.

More importantly, the 6D allows for easy switch to Eg-S focus screen unlike the 5D3 - so IMO 6D actually has a significant advantage for manually focusing the f/1.2 lenses and seeing their true DOF in the viewfinder.

Yes, the focusing screen can be installed (I have the Eg-S screen) but I'm specifically commenting on the AF which doesn't work too well with very large aperture lenses. Comparing the 5D3 AF with the 6D MF with Eg-S screen is like comparing apples to oranges. The 5D3 outer AF points will lock on with superb precision and you would have already taken the shot and moved on to another in the same time you would be focusing manually with the 6D.

Its not really comparing apples with oranges because the Eg-S allows you to see in the viewfinder more accurate DOF - even when autofocusing - than the 5D3's stock screen which is not user replaceable. 5D3's fixed focus screen only shows about f/2.8 DOF while the Eg-S on the 6D will come close to the DOF of f/1.2.

So, the fact that the 6D allows the user to swap to Eg-S means that what you see in the viewfinder when both AF *and* MF will more accurately represent the end product. If you do choose to MF to that end product, it is worlds easier on the 6D using Eg-S vs the 5D3's fixed screen.

Yes, the 5D3 will likely allow to set up your shots faster, but that does not make the 6D AF useless.

One could argue you are looking for trouble in general if you try to autofocus at f/1.2 all the time no matter what camera you use.

All EOS cameras AF with the lenses wide open, so a f/1.2 lens will AF wide open at f/1.2 no matter what settings you use to shoot.

Correct, when aperture is set to f/1.2 DOF is so thin that the very slightest difference between where you thought you were focusing and where the actual camera focused will cause loss of detail. MF with Eg-S/matte screen allows you to easily see if you got the shot or not before you take it - and you don't even have to go into Live View.

The cross type outer AF points work extremely well on the 5D3. See below photo taken with a 5D3 with 85L II - 100% crop of the AF area also provided - I have been using this combo for quite a while now and am happy with the results.

Not saying that 6D is a bad camera, but the whinging that takes place over the AF happens deservedly so.

Edit: I'm not sure how to post the 100% crop. The 100% crop image that I can view here on CR is larger than what I see in LR with a 1:1 view - any tips on how to post the exact image?

I think the whining about the 6D AF depends of what you take shots of. Birds, sure, the 6D AF probably not good for that. But for shooting people, the 6D AF is superb. Finally when one wants to MF (or see DOF when AF in viewfinder below f/2. 8), as one often may want to with an f/1.2 DOF, the 6D actually is better than the 5D3 IMO.

If the 5D3 had a user replaceable focus screen like the 6D (or a stock screen similar to the Eg-s) I'd be quicker to throw the 6D under the bus, but the 5D3 does not, which is certainly a large demerit against the 5D3 when AF or MF in the viewfinder with fast lenses at apertures wider than f/2. 8.

 

[Fotofanten]

CarlTN: I focus and recompose too. It's never been a problem, even with a 50L on a 6D. If I am getting paid for the shot then sure, I bag a few extra shots before I move on. The same goes if the subject is a person and he or she is not perfectly still, if its windy, or if I've had a couple of glasses of wine. As long as I am not careless I am fine. I always pixel peep, so as to learn from my mistakes. Focusing and recomposing is not the end of the world as some would have you believe. That being said, I do look forward to the day there is a camera that lets me place the focus point fast and effortlessly and that provides the same hit-ratio as focusing and recomposing + practice does. If you feel the need to use anything but the centre point, I do agree that the 6D AF is inadequate.

 

[whothafunk]

6D's AF capabilities and focus points are just plain sad for today's standards for a camera worth that much money and a FF label. Some people defend it by saying "it can take sports photos too!". Sure it can, I did it with my 550D also. I can make my eggs on a hot engine of my car, but I can do better.

Nobody denies 6D's low light focusing ability though.

 

[cheeseheadsaint]

I primarily shoot sports(quidditch see: http://www.canonrumors.com/forum/index.php?topic=20529) and the 6D serves me well. Then again, my previous and first dslr was the Rebel XSi(so my perspective is different) and I shoot with only the center focus point and use back button focusing to recompose. Crop in post if necessary. Most of the time my shots are in focus but a significant chunk is also annoyingly blurring my intended subject and tracking on someone next to them instead. I feel like the back button focusing isn't as reliable -or maybe I'm doing it wrong. Are you supposed to be holding the backbutton(what I've been doing) or just press it once? I'm shooting in AI Servo.

 

[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?

I thought you were discussing side AF points. Those eyes look pretty centered in the FOV to me, unless this is heavily cropped...which I doubt.

As I mentioned, 1st photo came straight out from camera, untouch, JPEG.

The only I did reduced photo size down to 3000x2000 for posting purpose(zero cropping). It was a 3rd outer AF point, from the center.

I'm not bashing 6D, but the #1 reason I went from 5D II to 5D III is 61 AF points. 5D II feel much better in hand...that just me of course.

 

[Dylan777]

I thought you were discussing side AF points. Those eyes look pretty centered in the FOV to me, unless this is heavily cropped...which I doubt.

Did you read the description? There is no crop. Her right eye is near the center of the frame, and because she is nearly parallel to the sensor plane it is in focus. But AF was on her left eye.

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

I get that kind of performance from my 5D3 outer cross-type points too (in one shot, I disable non-cross type AF), at least as best I can tell with shallow DOF from say 200mm/2.8.

5D2? Not so much. The 6D outer points are vertical line sensors like the 5D2, right? In landscape orientation it will just hunt on the outlying points if there is no vertical contrast. The 1Dx unit is sensitive in two directions widely across the frame. That's a significant improvement over the 5D2/6D.

I don't know of anyone who wanted a 5D3 at 6D prices. Rather, I suspect there are plenty who would pay $4500 for a 5D3.

Willingness to pay and a desire to pay are two different things. I certainly would have wanted a 5D3 at 6D prices. However, that's unrealistic.

As for there being plenty who would pay $4,500... I don't know. There may be some, but at that point, many may look elsewhere or decide to save a little bit more for the 1Dx.

+1....same here 3kramd5. It's nice to have over 40 cross type AF points.