error 99

[scottyh]

Help everyone!!

i got an eos 300d in november 2004 and i'm really happy with it! except when i try & use it to take pictures of windsurfing. I'm using either a tokina 150-400 ef zoom or a sigma 70-210 zoom. and when i'm taking pictures with a high proportion of grey sky and sea i get an "error 99" this does not happen if i use manual focus and seems especially bad at the shorter end of the lenses range. If i use the supplied ef 18-35 to take scenic shots in thesame conditions no worries and the above 2 lenses work fine on AF mode with a 35mm film eos ??
i tried adjusting my focus weighting so it's a single point but still no joy.

so do you reckon the camera is at fault or is there someting i'm not setting up corectly or will it really not work with all ef compatible lenses??

thanks in advance guys

scott

[cmM]

that is a communication error. First thing you should check is how clean your lens contacts are.

[Jon]

Some older third-party EF lenses will consistently cause Err 99 when the camera tries to stop them down to smaller apertures. Older Sigmas are most commonly known for this, and Sigma has been willing to re-chip them with updated electronics. The problem due to the other manufacturers' having to reverse-engineer what Canon was doing in camera-lens communication. As Canon enabled progressively more features in the camera, the lenses which didn't know about these features couldn't handle them properly. Canon's EF lenses have been able to cope with all the new features. But Canon doesn't guarantee that anyone else will be able to figure out what they did, and doesn't license the technology to anyone.

If you can get these lenses to consistently fail under repeatable circumstances, you might try testing them on a 10D, 20D, or maybe a D60 and the same conditions. If they fail there as well, it's the lens not being able to cope. If they work, the problem's most likely with your camera. As cmM said, start by cleaning your contacts (lens and body sides), and also make sure the lenses are fully seated on the mount.

[scottyh]

thanks guys,

i'll clean the contacts and i'll go for an aperture priority setting that's really open. Failing that i'll try & take the lens to a canon dealer to try on a 1d or 10d .