cancel
Showing results for 
Search instead for 
Did you mean: 

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

Photogirl55
Apprentice

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.

223 REPLIES 223

I think that the issue comes from a camera/lens combination and it cannot be fixed. Don't know if the 7Dmkii is better or not.

 

I have no focus issues with slow lenses like the 15-85 from Canon or the 70-300 from Tamron. But  with fast wide angle lenses, the focus only works at short distances below 2 meters, beyond that the focus is awful and very erratic. But it's not the case for all wide angle lenses, and it's not an issue with AF algorithm on third party lens manufacturer, because I have almost no focus issues with the older Sigma 30mm 1.4, but have a lot of focus issues with the 24 1.4 and 18-35 1.8. Only way I could solve that issue is to use either LiveView or zone focusing.

 

I now think that the issue comes from the way the lens is built and the 70D's AF being not precise enough for the lens. Maybe that the best way to prevent that issue from happening is to look on the focus scale of the lens.

 

In short : as a rule of thumb, don't buy a lens if the amount of turn between 1 meter and infinity is too small, it will not work well on the 70D.

 

To get an idea, just look at pictures of the focus scales of Sigma's 24mm 1.4 (have focus issues) and the older 30mm 1.4 (almost no focus issues). On the 24mm the amount of turn is extremely small and the optical quality is very good, so slightest imprecision from the AF will give you blurry pictures. On that lens, I also have a hard time adjusting the focus by hand, slightest touch of the focusing ring blurs the picture.

 

Also other actions should give you better results (unfortunately they don't all involve the 70D) :

- check the lens focus travel, if it's too short don't buy the lens

- go full frame (heavier, but larger pixels giving better low light performance and less precise AF is needed)

 - buy a mirorless (AF will be slower and they mostly come with electronic viewfinder, but at least the focus is done directly on the imaging sensor).


@Molybdo42 wrote:

 

 

In short : as a rule of thumb, don't buy a lens if the amount of turn between 1 meter and infinity is too small, it will not work well on the 70D.

 

And yet all of my lenses (including fast - f/2.8 and f/1.8 lenses) work perfectly all the time on my 70D, regardless of the distance to subject.

 

Your limited personal experiences form no basis whatsoever for a "rule of thumb".

 

As I said, fast lenses can work on a 70D, you just have to be aware that if the lens needs a very high AF precision it will not work. By the way that issue isn't limited to the 70D and also happens on my 60D.

 

On my sigma 24 mm 1.4 lens, if I want to focus manually I have to turn the focus very precisely, no room for error. On my Sigma 30mm 1.4, the lens is softer and the amount of turn is much larger, giving me more room for error.

 

What are your lenses ? Does the focus scale indicate a number between 1 meter and infinity ? Or is it too short to print a number ? Do you have any hard time hand focusing them ?

 

What I said depends on three things :

- optical quality of the lens (on a sharper lens focus issue is more visible)

- focal length (longer focal length need more displacement of the lens elements to focus, also maybe that the AF is less precise with wide angles)

- aperture

 

You only cited your lens aperture...


@kcatle wrote:

hat is my backup plan if I try another 70d and still have the issues that we have all seen.



I have never heard of this issue with the 7D II.  I don't own a 70D and, for a while, I didn't even know anyone who had a 70D so I was unable to do any first-hand testing or evaluation to determine if the issue was even "real" (consumers will pile-on to an invalid claim.)   Now that I know a few people who own the 70D -- I asked them about their experiences and they seem to be completely happy and claim they have no focus issues.

 

I own a 5D II and 5D III body and I own 7 different Canon lenses.  I also happen to own a focus test/calibration chart and all of my lenses have been tested.  As I've tested each lens, I had not encountered a lens that could benefit from adjustment. But I have rented lenses and each of the rented lenses needed a very tiny adjustment.  

 

Just to be clear... same camera body... different lenses.  Some need adjustment, some don't.  This is normal.  Neither the body nor lenses are defective just because they need adjustment.

 

When it's not possible to correct for minor amounts of focus error by using the AFMA feature then there's probably a legitimate issue with the camera body.  I expect this is probably very rare.

 

I have a niece who owns two different Canon bodies and has (or rather had) the EF 50mm f/1.8 II.  She was happy with the focus performance.  That lens was damaged, so she replaced it with the new EF 50mm f/1.8 STM -- but notices that it misses focus at f/1.8.  I had her re-evaluate using "live view" and she confirmed (as I suspected) that it nails the focus in live-view but misses focus when using the viewfinder... but just this one lens.  This is not all that unusual and it's the reason camera bodies have AFMA.  Unfortunately both her cameras are Rebel series bodies and do not support AFMA.  She'll have to try a different copy of the lens.

 

 

 

 

Tim Campbell
5D III, 5D IV, 60Da


@kcatle wrote:

 

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.


There is no "issue". Just - maybe - a small number of faulty bodies, and - definitely - a higher number of users who need to learn how to use a camera.
My 7D Mk II is fantastic, but my 70D is only a hair behind it in terms of AF accuracy.

 

Interesting info for the 7D mkII but even zoom lenses don't work well with the 7D mkii AF, I haven't yet found a pattern : is it dependent on the construction, the maximum aperture, the release date... Hard to say.

 

Back button focus is grea,t it allows me to leave the lens AF on and only use it when I need it.

 

Regarding the size of the focus box of the 7D, I measured the same thing on my 70D and obtained smaller and decentered focus box, some marks are only half covered :

 

40mm_f2-8.jpg

 

I already had my first camera body exchanged by Canon because the first copy was worst than this. WIth this new copy it's better but it's still not perfect. I first though it was a manufacturing issue, but now I don't know if that's how the camera is supposed to behave.

 

If you look at the car's picture on the left, I made sure the plants were way outside the sensitive area (look at the position of the surrounding focus marks). The camera didn't obviously focus on the plants in the foreground, something must have fooled it and this is why some users say there is a focus issue.

 

 

I can't yet understand why something way outside the AF sensitive zone would do this. This is why I want to understand what the AF sees in different situations. For example, how big does the subject need to be, what color, what lightning conditions will give me good accurate focus. When I read the 7Dmkii manual I simply can't stop telling myself that the camera can't focus on something that small ! Look at the squirrel p22, it's eye simply isn't contrasted enough, the cars I aimed at where brighter than that.

 

I think we are more dealing with an AF precision issue not visible on a full frame sensor and with small aperture lenses. I also kind of wished Canon decided to include spot focus on the 70D. This camera is impossible to use if I have to be extra careful on how I frame the picture, making sure nothing else too distracting for the AF occupies 10-20% of the entire frame.

Also look in Andre's blog link you provided me, focus points number 1-2 and 4-5 are identical, how can I know where to aim to get good results ? The center of the focus sensitive zone ? The center of the box ?

 

On a 70D AF on fast wide angle lenses is simply unreliable, no amount of technique can solve that issue, I shouldn't have bought a 70D.


@Molybdo42 wrote:

. . .

 

If you look at the car's picture on the left, I made sure the plants were way outside the sensitive area (look at the position of the surrounding focus marks). The camera didn't obviously focus on the plants in the foreground, something must have fooled it and this is why some users say there is a focus issue.

 

 

I can't yet understand why something way outside the AF sensitive zone would do this. This is why I want to understand what the AF sees in different situations. For example, how big does the subject need to be, what color, what lightning conditions will give me good accurate focus.

. . .


On the classic 7D there is a vertical extended zig zag AF sensor that runs from top to bottom in the center. It is supposed to speed focus when the lens is extremely defocused getting the camera in the ballpark. But, on the classic 7D, just like it appears to have done on your 70D and the plants it sometimes seems to extend the height of the center AF point when there is strong contrast just outside the normal AF area and less contrast in the AF area. It's just one of those things you learn about your camera. Once you learn how your cameras AF behaves all of this will really become second nature. But, it does take getting past believing it is not normal, and moving on to learning what it does do.

Canon-EOS-7D-AF-Sensor-Config (1).gif

 

 I also wonder if the size of the focus boxes vary at all with the focal length of the lens, that is something I haven't tested.


@Molybdo42 wrote:

. . .

 

 

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 ?


We are subjecting cameras to higher degrees of scrutiny. In the days of film cameras and early digital cameras the AF standard was that the focus plane fell within the depth of field for a consumer camera, and within the 1/3 center for pro cameras.

 

The thing to keep in mind was that that depth of field was based on either an 8X10 or 11X14 print at normal viewing distances. When we look at a 20 megapixel photo at 100% on a computer monitor it is equivalent to staring at a 3'X5' poster size print from 28 inches away. Use those parameters in a depth of field calculation and you find that it becomes a minuscule fraction of what cameras were designed for. This exaggerates even the smallest focus error. Take that same photo with that small focus error and make an 8X10 print and it would look fine. View the whole photo on an electronic display at normal viewing distances and it would look fine.

 

So it's not so much about focal lengths and sensor sizes as it is about pixel peeping on computer monitors. 

 

I can provide links to technical documentation for all of the above. So if there is a specific point you'd like to learn more about just ask.

Of course that reducing the file size will help but I still want to be able to keep the full res picture to reframe in post if needed. I won't be trying to use autofocus with a wide angle lens anymore (at least on an APSC camera).

 

If you have any documentation detailing the elements taken into account by the camera during AF post them, I'm still trying to figure it out. But I would like informations about the 19 AF point sensor.

For example the lightning condition (stray light, shadows) seem to have an impact on my AF performance. Is there a way to configure it in the options ? Any information or tips will be welcome.

 

My dream camera would look like a full frame sensor (for lowlight : no noise at mini ISO 6400), as lightweight as possible, with touchscreen, swivel screen, 15-20 Mpx max (for noise issue), dual pixel AF and integrated flash (never use it but in a pinch...)... In short : a 70D with full frame sensor.

 

Last thing : I hope you are ready for the "5Ds focus issue" post Smiley Tongue

You don't feel it was covered in the videos?

 

They certain some of the most comprehensive information on Canon's AF, the AF system in the 70D is a direct descendant of the AF system in the 1D Mk III so even that part of the 3rd video applies to some extent.. 

Announcements

08/09/2022: New firmware version 1.2.0 is available for CR-N 300
08/09/2022: New firmware version 1.2.0 is available for CR-N 500
07/28/2022: New firmware version 1.2.1 is available for EOS-R3
07/21/2022: New firmware version 1.6.0 is available for EOS-R5
07/21/2022: New firmware version 1.6.0 is available for EOS-R6
07/21/2022: New firmware version 1.1.0 is available for EOS-R7
07/21/2022: New firmware version 1.1.0 is available for EOS-R10
07/14/2022: New firmware version 1.0.1 is available for CR-X300
07/01/2022: New firmware version 1.3.0 is available for PowerShot PICK
06/30/2022: Service Notice: EOS 70D: Error 70 or Error 80
06/10/2022: Service Notice:UPDATE: Canon Inkjet Printer continuous reboot loop or powering down
06/07/2022: New firmware version 1.3.2 is available for PowerShot G7 X Mark III
06/07/2022: New firmware version 1.0.3 is available for EOS M50 Mark II
05/31/2022: Did someone SAY Badges?
05/26/2022: New firmware version 1.0.5.1 is available for EOS-C500 Mark II
05/26/2022: New firmware version 1.0.3.1 is available for EOS-C300 Mark III
05/10/2022: Keep your Canon gear in optimal condition with a Canon Maintenance Service
05/05/2022: We are excited to announce that we have refreshed the ranking scale within the community!
04/26/2022: New firmware version 1.0.1.1 is available for EOS R5 C
03/23/2022: New firmware version 1.0.3.1 is available for EOS-C70
02/09/2022: Share Your Photos is back!
02/07/2022: New firmware version 1.6.1 is available for EOS-1DX Mark III
01/19/2022: READY FOR ANYTHING EOS-R5 C
01/13/2022: Community Update. We will be retiring the legacy profile avatars on 01/20/2022. Click this link to read more.
01/05/2022: Welcome to CES 2022!
12/7/2021: New firmware version 1.3.0 is available for Mount Adapter EF-EOS R 0.71x