Canon 5Ds r autofocus problems

[Ethan]

Just bought the 5Ds r and have used it once (yesterday) on a shoot. Seemed to work fine. Picked it up today and the autofocus doesn't work with either of the two lenses I have at my disposal. I haven't changed a thing that I know of. I've cleared all custom functions and cleared camera settings to try and fix. Nothing has worked. Suggestions?

[TCampbell]

What are the two lenses?

If Canon, call Canon for support.

If 3rd party... this is mildy uncommon, but has certainly happened many times before (lens is "chipped" to be compatible with Canon bodies so far as the 3rd party lens maker has been able to test, but someone gets a new camera that the 3rd party lens maker has never tested before and they find out it's not compatible.)

You can contact the 3rd party to find out if they are aware of the problem.  Sometimes you can send them the lens and they can update the logic (assuming they have an update available.)

[Ethan]

Thanks for the reply Tim. The lenses are a Sigma 15mm and a Canon 24-70. I primarily use the Sigma and it seemed to be working fine yesterday. I can only assume that within the last 24 hrs that the contacts on the camera body have become corroded. This is hard for me to believe since the camera is brand new but I can't think of any other explanation. I don't see any corrosion and I've cleaned the contacts on both lenses. This is crazy irritating as I'm on the road supposed to be on a shoot over the next few days!!! I just left my old (but trustworthy) 5D MkII at home... 

[TCampbell]

The contacts are gold-plated. They don't corrode. They could become dirty -- but not corroded. The plating is thin, so Canon suggests using only a soft cloth (slightly moistened would be ok) to clean. But even a pencil eraser would be enough of an abrasive to remove the plating.

The Canon lens is certainly compatible with the camera. It's a 5Dsr -- so to get the benefit of the high resolution sensor, it makes sense to use high quality lenses. The 24-70 (especially the Mk II version) is very good glass.

I presume the AF/MF switch is in the AF position and you haven't done something like reconfigure to back button focus but are trying to use the front button focus (because I have NEVER made that mistake before *whistles innocently*).

[Ethan]

Yes, the AF/MF switch is in the AF position and I've been careful not to reconfigure any of the buttons. In any case, I have reset all the original camera settings a couple of times just to be sure.

It's kind of bizarre. I've kept playing around with it this afternoon and the autofocus seems to kick in once in a while but only for one or two shots. It then stops working. Again, it works fine in MF. This is driving me crazy - this being a brand-spanking new body!

[TCampbell]

Which autofocus mode are you using? The camera has many options.

Spot focus uses a reduced size AF point and isn't good on subjects lacking good contrast. Normal single point is better, but expanded and surround modes are even better if a subject lacks contrast. Canon makes numerous modes to make it easier for you and the camera to deal with focus situations -- even difficult focus situations. But you would want to make sure you are using an appropriate focus mode.

[Ethan]

I have tried each of the AF modes and none of them work. The lens isn't even trying to focus (in any mode) - using a subject with good contrast or one that doesn't. So, I don't believe it's the focus mode.

[TCampbell]

If the camera is in "One Shot" focus mode, will it take a photo?

I'm wondering if the lens "thinks" it's in MF mode (e.g. bad switch or something along those lines).  In "One Shot" mode, the camera uses "focus priority" and will (should) refuse to take a photo if it cannot get a focus lock.  But in MF mode it'll take a photo immedaitely (It will also take a photo immedaitely if in "AI Servo" mode.)

You could test it, take a photo (if it will), and then inspect the EXIF data to see if the camera or lens thinks the lens is in MF mode.

[Ethan]

In "one shot" it only takes a photo if I move the camera to the point where the image is in focus. That is, I have to move forward or backward until the subject is in focus and then the camera will take a photo. In MF it takes photos immediately and in AI Servo it takes them immediately, though the lens is still not trying to focus when I hold the shutter button down half way.

The EXIF data says it's in whatever mode I shoot in, i.e. one shot (moving the camera to a point where the image is in focus), AI Servo, or MF. 

I'm at my wits end BUT I really appreciate your help Tim!

[jrhoffman75]

Since it's a brand new camera don't rule out the possibility of an infant mortality failure.