Canon 1D mark III autofocus point blurry

[j_photograph]

I purchased a 1D III. I put a 50mm 1.8 and 17-40 L on it and noticed the center AF point is blurry. I adjusted the diopter, it's nice and sharp, except that point.

Can anyone recommend a fix for this? It does not affect photo quality, but it is kind of annoying. 

Any advice is appreciated. 

[deebatman316]

Is it always blurry. What about the other AF points are thy blurry. What happens if you set the aperture to F/11 and press the depth of field preview button. Does the center AF point become sharp. EF lenses keep the lens aperture wide open all the time. Until the picture is taken. This is to keep the viewfinder bright and provide as much light as possible to the AF system. 

[j_photograph]

Unfortunately it did not. I think it may be the focusing screen after some troubleshooting. thank you for your input

[deebatman316]

Your camera MAY NOT have user changeable focusing screens. Most newer 1D series cameras use an LCD overlay in the viewfinder. So there won't be a user changeable focusing screen.

[jrhoffman75]

From USCamera-dot-com

[rhj09]

Hi,

It sounds like the center AF point issue might be due to a viewfinder problem rather than the lenses. Here are a few steps to try:

1. Clean the Viewfinder: Dust or smudges can cause blurriness. Use a soft brush or blower to clean it gently.
2. Check the Focusing Screen: It might be misaligned or dirty. Refer to your camera's manual for cleaning or replacement instructions.
3. Diopter Adjustment: Ensure the diopter adjustment is correctly set for your eyesight.
4. Service Check: If the problem persists, consider taking your camera to a professional for inspection and servicing.

Hope this helps!

[deebatman316]

Not all 1D cameras have user changeable focusing screens. Most of Canon's newer DSLRs such as the 7D series, 5D MK III/ IV, 1DX Mark II & 6D Mark II. Utilize an LCD overlay in the viewfinder thus no user changeable focusing screens are available.

[Waddizzle]

Excerpt from artile linked just below….

“Ec-C IV Bright Laser-Matte. This is the standard screen for the EOS-1D Mark III/IV, and 1Ds Mark III. It has the same markings as the Ec-C III but is brighter, less grainy and better balanced.”

https://support.usa.canon.com/kb/index?page=content&id=ART170209 

[wq9nsc]

It isn't impossible for a focusing screen to be damaged while mounted in the camera but more likely a bit of debris or some other foreign material is in the center area.

1 series focusing screens are easy to change so I would first pull it and check it and if it is actually damaged then replace it.  There are several optional screens for 1 series bodies but unless you have special requirements, stay with the stock screen since some of the specialized screens will impact exposure metering and/or viewfinder brightness. 

Rodger