conurus

icechan · Joined: 08 Nov 2006 Posts: 5 Location: Hong Kong

Hihi,

I am using 50 f/1.4, but having a problem on a Canon 20D. After operating properly for a while, the camera fails to react (AF or whatever) the upper screen of the camera showing an aperture value of "0.0", meaning the camera can't recognize the lens.

The problem can't be corrected by switching off the camera. I have to take out the battery for a couple of second and the camera/lens returns to normal, which is quite disturbing when I try to take pictures of others.

I would like to know if this is due to my camera (being a old/outdated model) or what. For your reference as well, the camera is not in the "sleep" mode when the problem occurs. The SN is 12718169.

Thanks for your help.

Regards,

Mickey.

conurus · Posted: Fri Jan 08, 2010 4:19 pm Post subject:

Hi Mickey,

Your lens was serviced in July. Had the problem developed recently? Does the problem occur on only one camera body or more than one camera body?

0.0 is the result of bad contact between the camera body and the lens. You may see if there is play after attaching the lens by rotating it clockwise slightly and counterclockwise slighting after attaching (the lens is locked but there should be a very tiny little bit of leeway). Your camera may regain contact with the lens after some wiggling.

One possible cause is the springs of the camera's electrical contacts are losing strength. Problems such as this are usually specific to one camera/lens combination. You can take the same lens to another camera body and it would work fine. Conversely you can take the same camera body to another lens and it would work fine.

icechan · Joined: 08 Nov 2006 Posts: 5 Location: Hong Kong

Hi, thanks for your help.

Yes, I have the lens converted sometime ago, but actually I only "tested" the lens (after conversion) for one or two minutes. My recent vacation is only the first time I used the lens more intensively, really sorry for late reporting.

I used 50mm and 17-35mm in my vacation, no problem for the 17-35mm and other Canon lens, but the problem of 50mm occurs quite frequently (at least 1-2 times per day, during my 7 days vacation).

May need to try other converted lens on my 20D (sorry that I don't have other camera to test) and see if it works by your suggested method.

cheers.