Canon 70d center focus point -bug- problem

[koolman]

Hi,

I was considering upgrading from my t2i to the canon 70d. I use quite a few fast primes at 1.4 like the canon 50mm 1.4, and 35L 1.4.

There is quite a "buzz" on the net - claiming a focus problem with the 70d when using the view finder and center point for maximum accuracy. it seems there is a quirk which does not provide sharp focus.

Can anyone confirm or negate this ? If I cannot focus like my t2i with my fast glass - then the 70d is not for me?

 

[Mt Spokane Photography]

Hi,

I was considering upgrading from my t2i to the canon 70d. I use quite a few fast primes at 1.4 like the canon 50mm 1.4, and 35L 1.4.

There is quite a "buzz" on the net - claiming a focus problem with the 70d when using the view finder and center point for maximum accuracy. it seems there is a quirk which does not provide sharp focus.

Can anyone confirm or negate this ? If I cannot focus like my t2i with my fast glass - then the 70d is not for me?

Phase detect autofocus is fast, but is not as accurate as the dual pixel AF or manual AF either. I have not heard of any issues, do you have links to reliable testers that found a issue? Usually it is lens related, some lenses do not focus reliably or accurately. Be sure that the tester is experienced and knows what he is doing. Beware of posts on forums where testers make incorrect assumptions or use lenses that may not be consistent.

I've yet to see any expert reports of a issue that is repeatable using good lenses.

Here are some links to people who know what they are doing.

http://www.imaging-resource.com/news/2014/02/27/canon-dual-pixel-cmos-af-autofocus-secrets-of-the-canon-70d-explained

DP Review did a lot of testing and has some remarks specifically about AF accuracy.

http://www.dpreview.com/reviews/canon-eos-70d/12

 

[koolman]

Hi,

I was considering upgrading from my t2i to the canon 70d. I use quite a few fast primes at 1.4 like the canon 50mm 1.4, and 35L 1.4.

There is quite a "buzz" on the net - claiming a focus problem with the 70d when using the view finder and center point for maximum accuracy. it seems there is a quirk which does not provide sharp focus.

Can anyone confirm or negate this ? If I cannot focus like my t2i with my fast glass - then the 70d is not for me?

Phase detect autofocus is fast, but is not as accurate as the dual pixel AF or manual AF either. I have not heard of any issues, do you have links to reliable testers that found a issue? Usually it is lens related, some lenses do not focus reliably or accurately. Be sure that the tester is experienced and knows what he is doing. Beware of posts on forums where testers make incorrect assumptions or use lenses that may not be consistent.

I've yet to see any expert reports of a issue that is repeatable using good lenses.

Here are some links to people who know what they are doing.

http://www.imaging-resource.com/news/2014/02/27/canon-dual-pixel-cmos-af-autofocus-secrets-of-the-canon-70d-explained

DP Review did a lot of testing and has some remarks specifically about AF accuracy.

http://www.dpreview.com/reviews/canon-eos-70d/12

Here are links about this:

Canon 70D- Serious Focusing Problem!

Canon 70D Focusing Issue

 

[Loswr]

Here are links about this:

Well, the first video is a useless joke. Evidence? I see none. Zero information about the lens used, the camera settings, or the set up. The most obvious answer to that "problem" is that the lens needs AFMA – sharper with live view than with phase AF is the easiest test to determine that. I chuckled at the claim that "a good knowledge of photography" is necessary to detect the problem. That's what we call irony. :

The second video says exactly what I just said – the focus was off with the 50/1.4 at f/1.4, and AFMA corrected the problem. Duh. He then goes on to suggest there is, in fact, a problem with some cameras – but he has no evidence for that, except "some people on the Internet say"…

Were these two videos the best 'evidence' you could come up with? I think the only problems you're seeing are wetware errors – the person holding the camera is the issue.

 

[Don Haines]

Here are links about this:

Well, the first video is a useless joke. Evidence? I see none. Zero information about the lens used, the camera settings, or the set up. The most obvious answer to that "problem" is that the lens needs AFMA – sharper with live view than with phase AF is the easiest test to determine that. I chuckled at the claim that "a good knowledge of photography" is necessary to detect the problem. That's what we call irony. :

The second video says exactly what I just said – the focus was off with the 50/1.4 at f/1.4, and AFMA corrected the problem. Duh. He then goes on to suggest there is, in fact, a problem with some cameras – but he has no evidence for that, except "some people on the Internet say"…

Were these two videos the best 'evidence' you could come up with? I think the only problems you're seeing are wetware errors – the person holding the camera is the issue.

Who would have thought that moving a camera a greater distance than the DOF would result in blurry pictures! Next thing you know, people will discover that the 1DX does not focus well with the lens cap on....

 

[Loswr]

Next thing you know, people will discover that the 1DX does not focus well with the lens cap on....

So that's what I've been doing wrong!!!

 

[alistairm1]

check this out for a bit more detail.

http://photography-on-the.net/forum/showthread.php?t=1354075


Not all the people reporting issues are as poor at photography as your comments suggest.

 

[Loswr]

check this out for a bit more detail.

http://photography-on-the.net/forum/showthread.php?t=1354075


Not all the people reporting issues are as poor at photography as your comments suggest.

Yep, lots of experts there...

Like the person who states, "I may also try on a T1i to see if FoCal can come up with an MFA number for my 50/1.4 on that." I wonder how much luck he'll have with that. :

Or all the people saying the 70D has inconsistent AF…but they're using a 50/1.8 which is one of Canon's poorest-focusing lenses.

Or the person who states, "AFMA should generally correct across the range" of distances, which is far from true.

So, we have a few complaints on the internet, lots of poor testing by 'experts', and the known reality that in any production line there are defective units that make it past QC, so there are undoubtedly a very small number of actually defective units out there.

That, and claims of a Canon coverup. Egad, we'd better all switch to Nikon, where that sort of thing never happens. :-X

 

[alistairm1]

Just picked a few out of 35 pages-worth.
Better just tell them all to get a 1Dx then all their problems will go away.

Just joined this forum, but it doesn't seem to be all than friendly.

I'll contact the admins to get unregistered.

Sorry to have wasted your valuable time

 

[Loswr]

Just picked a few out of 35 pages-worth.
Better just tell them all to get a 1Dx then all their problems will go away.

Just joined this forum, but it doesn't seem to be all than friendly.

I'll contact the admins to get unregistered.

Sorry to have wasted your valuable time

Sorry you feel that way. But honestly, I don't see anything in those 35 pages or the two videos the OP linked that are consistent with this being a widespread problem. Once you eliminate the people who don't know about or haven't tried AFMA, the people who aren't testing properly, the people who are using lenses with known AF inconsistency (Canon 50/1.8, almost every Sigma lens), and the people with unrelated issues (many of which also boil down to user error), and once you subtract the people in that 35-page thread that tested for this specific problem with their 70D and found it worked properly, you really aren't left with much of an issue.

Particularly in this thread…the OP is wondering if the 70D should not be purchased because of the 'buzz' about this 'problem'. I see no reason to avoid the 70D over this non-issue.

alistairm1, are you experiencing AF issues with your 70D? If so, what steps have you performed to identify and troubleshoot the issue?

 

[alistairm1]

I haven't bought one as I can see other people having problems with theirs.
Just as I wouldn't buy anything else which has issues reported and which doesn't seem to have any sort of fix available.

I'm sure you are the same.

Or maybe not.

 

[Loswr]

I haven't bought one as I can see other people having problems with theirs.
Just as I wouldn't buy anything else which has issues reported and which doesn't seem to have any sort of fix available.

I'm surprised you've bought anything at all. Do you have a dSLR now? Google search for that camera and 'problems'. Do a search on anything you've bought - a car, HDTV, computer, whatever, with the word "problems" appended. I bet you'll get hundreds of thousands if not millions of hits. You'll find forums with people reporting problems of all kinds. My cars give close to a million 'problems' hits each. My HDTV gives close to 50 million 'problems' hits. Over 70 million hits for one of my laptops. My cars, TV, and laptops have worked flawlessly since the day I bought them.

Reports of problems on the internet are a very poor guide for buying choices.

 

[jarrieta]

Have gone through the POTN thread and some people there are even implying that people "without" this problem do not know how to use their cameras. So, I guess the people posting excellent shots on the 70d sample thread don't know how to use their 70ds.

 

[Don Haines]

I haven't bought one as I can see other people having problems with theirs.
Just as I wouldn't buy anything else which has issues reported and which doesn't seem to have any sort of fix available.

I'm sure you are the same.

Or maybe not.

Alistair, it does not matter which camera model you get or from which company.... you can find "experts" who claim that the camera has problems and that there is a conspiracy. Sometimes these claims are true, like the Nikon oil-on-sensor issue, but in the vast majority of cases it comes from people not knowing what they are doing or having the settings wrong.

A classic example of that is the Tamron 150-600 which came out recently. A number of users were complaining that the AF on the lens would not work, yet they had the camera set into a mode where it would quickly abandon attempts at AF and just "give up", when all they had to do was to set the mode to "continue autofocus".

Auto-focus on fast lenses is very problematic, from any company. The in-focus range of some of those lenses can be less than half of a centimeter. Any forward/backward/up/down/angle movement after you have locked on focus will take you out of focus.. You really need a tripod under those conditions. One of my favourite lenses in the 100L... the DOF on that lens is miniscule... take a picture of a bee wide open and you can't even get the whole head in focus... it's DOF is that narrow! The depth of field calculator gives me a number of <1mm.

With a fast lens used wide open, AFMA is almost essential to good focus, yet few users AFMA their lenses, and of those who do, most do not do it right and may actually be making the problem worse.

 

[AlanF]

My 70D focusses very accurately and consistently with centre spot. It is much, much better than my previous 7D and as good as my 5DIII.

 

[Don Haines]

I also why "30-50 percent of cameras in Germany" have this problem....

shouldn't the whole world have this problem if it exists?????

 

[unadog]

I also why "30-50 percent of cameras in Germany" have this problem....

Hysteria!!


The second video should have taken this on much more strongly. This is just nonsense,

1. YOU CANNOT HAND HOLD AN 85 1.2 or 50 1.4 and hit your focus target consistently wide open!

2. YOU CANNOT FOCUS AND RECOMPOSE wide open! The camera needs to be locked down on a tripod for these tests.

3. You have to learn A LOT about autofocus to understand how to accurately test your focus.

From Roger Cicala: "Why You Can't Optically Test Your Lens With Autofocus"

http://www.lensrentals.com/blog/2014/02/why-you-cant-optically-test-your-lens-with-autofocus


4. You have to learn A LOT about autofocus to understand the different features/settings on auto focus.

Anyone who has ever owned a 1DX, for example, will tell you that they had to study the auto focus manual for that camera to learn all of the features. And then test like hell to underastand exactly how to use it in the field.

One example: You can select and set the sensitivity of first shot "focus acquisition priority or shutter release priority."Basically - do you want the camera to ensure absolute best focus before taking a shot, or have a bias toward taking the shot no matter what?


Then you can also tune that for subsequent shots. And that is just one of the focus modes. This is a 55 page book we are talkinmg about:

"Mastering the EOS 1D X's Autofocus System"

http://www.learn.usa.canon.com/resources/articles/2012/1dx_guidebook.shtml


Also time to read up on more of Roger Cicala's posts on auto focus:

http://www.lensrentals.com/blog/2012/07/autofocus-reality-part-1-center-point-single-shot-accuracy

http://www.lensrentals.com/blog/2012/07/autofocus-reality-part-ii-1-vs-2-and-old-vs-new

http://www.lensrentals.com/blog/2012/08/autofocus-reality-part-3b-canon-cameras


These people need to be educate themselves and digest that information before we can talk about an issue with the 70D. This is just the way that the world works.

When Roger tells me that there is a problem with the 70D, I will believe him.

Cheers!

 

[unadog]

Have gone through the POTN thread and some people there are even implying that people "without" this problem do not know how to use their cameras. So, I guess the people posting excellent shots on the 70d sample thread don't know how to use their 70ds.

Ah - the dreaded "Dunning-Kruger Effect":

"The skills needed to produce logically sound arguments, for instance, are the same skills that are necessary to recognize when a logically sound argument has been made. Thus, if people lack the skills to produce correct answers, they are also cursed with an inability to know when their answers, or anyone else's, are right or wrong. They cannot recognize their responses as mistaken, or other people's responses as superior to their own."


"The Dunning-Kruger effect occurs where people fail to adequately assess their level of competence — or specifically, their incompetence — at a task.

This lack of awareness is attributed to their lower level of competence robbing them of the ability to critically analyse their performance, leading to a significant overestimate of themselves. Put more crudely, they're too stupid to realize they're stupid."

 

[Luds34]

I picked up a 70D in January. Probably a month after owning it, a good buddy (fellow 70D owner) asked me if I had heard about the "70D center point focus issue" and included a ton of links. My understanding is this is/was a legit issue for some bodies. A bad production run, a bad batch, whatever, that ended up mostly in Germany?

So of course a bit paranoid about my new toy I spent a little more time then was probably healthy reading up on this and doing some testing. I'm not a test chart shooting kind of guy. I prefer to just keep it to "real world" feel of how equipment performs. However, for this possible issue I busted out the charts, my 4 fastest lenses, shot a hundred or so shots at different distances, constantly cycling back and forth between live view and viewfinder, manually setting out-of-focus near on one shot, far on the next, taking notes, and then studying on a monitor.

Short story, final result for me? My body (and lenses) all shot fine.

Slightly longer story, is that at first I did see a slight issue with my 28mm f/1.8 and to a lesser degree my 85mm f/1.8. Pixel peeping on the monitor showed a purple hue when using the built in phase detection while the live view phase detection did not. Even though historically I have had great luck focusing with my 28mm, I first thought maybe it was back focusing a little and needed to be compensated for. But then I realized I was exclusively lighting my subject (test charts) with daylight CFLs which can have an affect on PDAF. So I duplicated the tests during the day in with natural light and I could not reproduce the very slight mis-focus issues I was seeing the night before.

So my 70D is working great.

Oh, and to the OP, whom I believe was considering upgrading from a T2i, that is exactly what I did. Love the upgrade. My style is to shoot almost exclusively with the center point and while the 550D worked great for me, the 70D is just a step up in consistency and feels to do better in low light when it comes to focus accuracy (just comparing center point to center point). All around it's just a better experience, from the big marketing spec things like live view phase detection (works great for macro work) to just being that prosumer body with all the little things that help (rear dial, dedicated buttons for things like drive mode or BBF, top lcd). Even something as dumb as how it feels in my hands. I'll carry the 70D one handed and don't fear dropping it. The Rebel was just too small and felt like I was more pinching it with my fingers then wrapping my hand around it (granted I have large hands).

My Rebel is in a small camera bag with the 40mm pancake lens attached. The small size makes it easy to bring almost anywhere. I really wish Canon would do an EF-S 22mm or so pancake as that would make a great, compact walk around (40mm is just a little too long on crop) setup. That "old" 18 MP sensor still takes great pictures.

 

[Slyham]

This issue really says one thing: DPAF rocks! Some of the videos out there are pixel peeping at 200% to notice the difference. This is not a new issue, but since live view focusing is suddenly super accurate people start to realize that phase detection AF has acceptable tolerances. That is why AFMA was created.