Wednesday, April 28, 2010

Canon 7D Auto-Focus Issues?

Hello readers!

I am saddened to say, I had to send my Canon 7D in to Canon for repairs. Now, if you have been following the news about this camera you may have heard of excessive noise issues and auto-focusing issues throughout the internet. Fortunately this is something that does not seem to be happening (or have happened) to all Canon 7D's. However, a few out there do seem to be plagued by very unfocused images in conditions that should otherwise have had nice focus. Now, do NOT confuse this for unsharp images. Due to the Canon 7D's high pixel count, images will require a higher level of sharpening to achieve what other (less megapixel) models may have required. Don't let that fool you into thinking it's not a quality image though. However, if you focus and snap a few shots, and in post... even at sharpness setting 100 (or 135 even) you still have a soft image, then you most likely missed the focus somehow.

I have been shooting snaps off all month, and I can count on one hand the number of sharp images I achieved. I checked, achieving the same results on 3 different lenses. So it finally had to go back, fingers crossed that it returns with an amazing focus ability and low noise production (as some have reported post repair submitting).

Below I'll post a few of the images. These pictures have had NO sharpening applied (I tried, it didn't change much, for those not in focus to begin with).

Note that the shutter speed is 1/800, with an f/5.6 in most if not all these images. Keep in mind that at these speeds camera shake should be completely eliminated (I'm shooting at 4x with focal length) and I am not at a shallow depth of field either. For those who may state that lenses have a sweet spot at f/8 and I should have shot at f/8 clearly... keep in mind the resolving power of the Canon 7D places most lenses into a new sweetspot to avoid reaching the difraction point.

Properly Focused Image:

100% Crop of Properly Focused Image (Above):


Now, let's look at the other 19 images (for the sake of speed, I'll only post 1, I can assure you they all look the same, despite changes in angle, distance, and zoom length).

Unproperly Focused Image:

100% Crop of Unproperly Focused Image (Above):

This was a series of 20 shots. One of them, was sharp... 19 were just as this one. These were shot using Center Point (not spot point or AF Zone) without any "modifiers" on the lens (Such as an UV filter). I'd like to take this opportunity to remind you that I was shooting at 4x to 7x the focal length in shutterspeed, making camera shake a very unlikely phenomenon (1/800th of a second), and especially unlikely 19 out of 20 times.

7 comments:

  1. Hi,

    I seem to be having the same issues as you with my 7D and all lenses. Please let me know if your camera is any better when it comes back from Canon. I would really appreciate it, as i'm debating sending mine in as well.

    Thanks!
    Matt

    matt@mattberkowitz.com

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  2. Sent you an email :)

    But basically, it has improved significantly! Check out the newest post for more info!

    -Dave

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  3. Dave, I just sent my 7d to cannon for the same problem. Did cannon indicate what they did to fix the problem?

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  4. Yes, I do know it is spelled Canon

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  5. Heya Kirk :)

    They stated in the paperwork that was included in the box that they:

    "Adjusted the focus mechanism, cleaned the sensor, and verified lack of noise"

    At the bottom of the page, it had another note stating "focusing tested - working"

    Thats all on the paper though, nothing else was written to indicated modifications or things done to the camera.

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  6. Thanks.

    That is all mine said and still getting erratic focus. Although I just found a setting in custom function IV-I that showed that lens was set to AF-Off rather than Metering and Autofocus (found this tip from a web search). So when I get a chance I'll retest and see if this was causing the issues. I looked at the manual but am not clear what AF-Stop set on the lens does.

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  7. Heya Kirk, if that solved your issue let me know :)

    Mine is working better for sure, but still erratic on occasion.

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