When will canon fix the focus issues with the 70D?

[Photogirl55]

I was "T.H.I.S." close to buying the 70D.  I have read WAYYY too many posts about issues with the focusing on the 70D.  How is Canon handling the issue?  I would love to buy this camera, but not willing to gamble with that much money.

[TTMartin]

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@Molybdo42 wrote:

@TTMartin : I don't understand why you want to limit the focus issue to that case in Germany.

The 70D simply has poor AF with fast wide angle lenses, same thing for the 7D.

Look at this forum http://www.canonrumors.com/forum/index.php?topic=3100.0

One user of the 7D and Canon's 24mm 1.4 L, found out that his camera could only work well in certain lightning conditions.

If the main shooting style of the users complaining here is to do night photography with the 70D, then they will get very inconsistent results. Unfortunately no one warned them and, like I did, fell into the trap now I need to find a work around. But if your shooting style is to do daytime photography then you won't notice any issue.

According to the forum I cited, the best solution would be to go full frame : better QC (?), better lowlight performance, less need for ultrawide angle to obtain the same field of view.

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The German issue seemed to be a real issue that should not be occurring with the camera. It was misinterpreted by some photo bloggers who put out some bad information. That being that phase detect AF (viewfinder) should be just as sharp as LiveView straight out of the box. That started the myth that their is some systemic problem with the AF of the 70D. LiveView and phase detect AF (viewfinder) use different sensors for auto focus. It is perfectly normal for you to need to micro focus adjust lenses to get them to obtain their maximum sharpness.

I followed the link you provided, from what I read certain copies of that lens can give inconsistent results with multiple Canon bodies. It certainly doesn't indicate that their is a specific problem with the 70D.

One thing to note is that many of the reports of 70D having AF issues mention the EF 50mm f/1.8 II. That lens is a 25 year old design with marginal build quality. It never was a strong AF performer on any camera. Now that Canon has released the EF 50mm f/1.8 STM lens, I expect the number people complaining about AF problems will drop. So in a way Canon did fix the 70D AF issue, they replaced the EF 50mm f/1.8 II with the EF 50mm f/1.8 STM.

[Molybdo42]

@TTMartin : I'm not arguing about the need or not to do mfa, it's just that whatever the AF algorithm does, it can give some out of focus results.

I did further testing and it looks like my camera doesn't work as well as I though in sunlight.

I now think the AF performance will depend a lot on the general illumination of the scene. The picture I had trouble with was taken in a scene illuminated by sunlight. I had no focus issue when aiming at the brightest element in the scene (a car light by sunlight). But I had noticeable defocus when aiming at a gray wall in the shade (the car I previously aimed at was clearly out of the focus sensitive area of the central focus point, but it was still in the field of view).

Now the eyes have a very good dynamic range, so what appeared to be bright in the shade, can be in fact too dark to focus on for the sensor, or the AF sensor might be distracted by stray light.

Canon's focus algorithm must be doing something to prevent the bright spots to saturate the AF detector, so the signal of shaded areas must be quite low, too low for the AF algorithm to consider.

For the ones with AF issues, could you try pointing the camera at the brightest element in the scene (aim at distant objects) ? And avoid pointing the camera at shaded areas. And then compare

The point I'm trying to make is that there is a clear limitation on most prosumer DSLR, not well documented because most users never where in a similar situation (either they don't have fast lens, either they use full frame sensor). Micro focus adjust could be in part to blame , but what appears to be a mfa issue might in fact be a limitation of the AF system.

I think we are converging towards gears that keep getting more challenging for the AF :

- Current generations of lenses from Sigma and Canon are very sharp,

- the DSLR sensors keep getting more pixels,

- Also, take into account the gear : on a 24mm 1.4, for a full frame sensor the hyperfocal distance is only 14 m, on an APSC it's 22 m.

- Take into account the lens construction : on these wide angle lenses the focus ring turn between 10m and infinity is extremely small

Because of those facts any focus issue won't be visible on a full frame sensor (you won't see any difference if the camera focused at 15 or 20 meters), but that error will be visible on an APSC sensor.

Also are AF sensors build differently between full frame and APSC, are they bigger, do they get more light ?

[TTMartin]

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@Molybdo42 wrote:

@TTMartin : I'm not arguing about the need or not to do mfa, it's just that whatever the AF algorithm does, it can give some out of focus results.

I did further testing and it looks like my camera doesn't work as well as I though in sunlight.

I now think the AF performance will depend a lot on the general illumination of the scene. The picture I had trouble with was taken in a scene illuminated by sunlight. I had no focus issue when aiming at the brightest element in the scene (a car light by sunlight). But I had noticeable defocus when aiming at a gray wall in the shade (the car I previously aimed at was clearly out of the focus sensitive area of the central focus point, but it was still in the field of view).

Now the eyes have a very good dynamic range, so what appeared to be bright in the shade, can be in fact too dark to focus on for the sensor, or the AF sensor might be distracted by stray light.

. . .

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AF systems require adequate contrast. What you describe is covered and explained in these 3 videos.

A Look at The Canon Autofocus System Part 1

A Look at The Canon Autofocus System Part 2

A Look at The Canon Autofocus System Part 3

Understanding what the capabilites of an AF system are and are not is key to getting the optimum results from your camera.

[Molybdo42]

I agree, contrasted objects help achieve better focus. But what I was aiming at in the shade appeared (to the naked eye) well contrasted and detailled enougth, see below (24mm 1.4 sigma lens) :

Apparently it wasn't enougth for the AF sensor. There might be a link between the metering and the AF sensitivity threshold.

I'll watch again the videos in case I missed some information.

[TTMartin]

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@Molybdo42 wrote:

I agree, contrasted objects help achieve better focus. But what I was aiming at in the shade appeared (to the naked eye) well contrasted and detailled enougth, see below (24mm 1.4 sigma lens) :

Apparently it wasn't enougth for the AF sensor. There might be a link between the metering and the AF sensitivity threshold.

I'll watch again the videos in case I missed some information.

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In the left photo the camera very obviously AF'd on the plants in the foreground. This can be explained by the AF point size as shown in Andre's Blog above. 

In the right photo the camera appears to have focused exactly where I would have expected it to focus.

[jeffandellie]

I am left to wonder what your motives are for flooding the thread with all kinds of unrelated nonsense and redirection and subject changes.

I noted half a dozen lenses that I tested, all canon except for one sigma (art series), and your response is that 3rd party lenses don't work well with canon – no acknowledgment of the canon lenses.

Then you start going off about the old timers and their issues, and you talk about your problem with wide angle and shadows, as if this is related, and throw in a bunch of info on focus systems.

You are condescending towards the people raising issues, you poo-poo all the issues, and basically have come out and said it is user error, a condition caused by a bunch of clueless consumers using camera gear that is over their head - while effectively burying the real grievances a few pages back in the thread.

I can only assume there is a reason you are doing this. is it possible that any of you are compensated in some form, way, or manner to purposely muddy the waters, redirect the conversation and bury the complaints? Would be an easy assumption for some, but who knows – we never will know the truth.. But this thread was dormant for the most part until you two demonstrated the need to flood it with many, many posts, which as noted basically buried the issues.

you refused to acknowledge that I tested ALL of my lenses (center focus square in viewfinder plus same exact pic in live view exactly per canon’s directions), at several apertures (and focal length in some cases) each, in bright but not direct sun, with a tripod, changing focus in-between sots so that the camera had to refocus, and did all of this not at the widest angle available, but generally in the 40-50 mm range. (In fact, the only lens done at 24mm was the 24mm prime)

ALL of my lenses produced the exact same effect at every aperture - the center square was WAY off of focus. Canon told me to send it in, which I did.

Also worth noting is that canon fixed the issue, without touching any of my lenses, and now none of my lenses need micro adjusting - or at least are so close that I have not noticed any lenses being off (except for my own bad pictures from cameras shake, etc. - as we all get on occasion).

Maybe my problem isn’t exactly the same as some others, and of course I have no way to verify the thousands of users who have had issues – can you get that data from canon? I can’t. I couldn’t even get them to tell me what they did to fix my camera. “check firmware, clean sensor” is all they would tell me. And of course I see no comments about the issue regarding the two different versions of the same firmware 1.1.1 (as noted by magic lantern developers for the 70D)

Yes, it is true that there are generally complaints with every new model of camera that comes out, but to try and suggest that with all the issues, it has 99.99% been user error is just plain ignorant and insulting, and looks to be intentionally misdirecting.

I’ve spent somewhere between 7,500 and 10,000 already, and I consider this payment enough to have my right to raise complaints.

[Molybdo42]

@ jeffandellie :

Sorry if I sound condescending, it's not my aim.

I''m trying to understand what would throw of the 70D focus so badly. I just got the Sigma 24 mm 1.4 lens last week, it cost me more than 950€.

I had a mind shift when I kind of accepted the camera doesn't play well with wide angle fast lenses because this allowed me to set correct values of mfa. I share this info, and now I'm beign told I'm condescending !?

[Molybdo42]

@ jeffandellie :

Also, if your 70D is fixed, can you please test the sigma 18-35 mm ? Mine behaves the same way as my 24 mm 1.4 : random focus depending on what I aim the camera at, even if it's well contrasted. I already sent that lens once to Sigma with the body for adjustment.

Can't acknowledge for your Canon lenses because I don't own these.

[kcatle]

Sorry if this question has already been answered (I went through several pages in this forum post but did not see a clear definitive answer to this).  Are there some 70ds that work out there?

I purchased and returned 2 based upon all of the issues that i had with focusing wtih f2.8 and more open.

I bought the camera 2 months after it was released - so wasnt sure if I were to buy now, if there is a chance that this issue would not exist with some models.

Any help on this question would help. Thanks so much guys. 

Also - Does this issue exist on the 7d mark ii. That is my backup plan if I try another 70d and still have the issues that we have all seen.

[TTMartin]

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@kcatle wrote:

Sorry if this question has already been answered (I went through several pages in this forum post but did not see a clear definitive answer to this).  Are there some 70ds that work out there?

I purchased and returned 2 based upon all of the issues that i had with focusing wtih f2.8 and more open.

I bought the camera 2 months after it was released - so wasnt sure if I were to buy now, if there is a chance that this issue would not exist with some models.

Any help on this question would help. Thanks so much guys. 

Also - Does this issue exist on the 7d mark ii. That is my backup plan if I try another 70d and still have the issues that we have all seen.

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Yes, the vast majority of 70D's work. But, you have to understand that it is perfectly normal to have to micro focus adjust a lens. If you felt that your other 70D's were 'defective' because they needed micro focus adjustment, then no Canon hasn't 'fixed' that because it is perfectly normal.