Yesterday at an Autocross i had the privledge to use a borrowed Canon EOS 10D.

Knowing i was going to be using the camera i brought my Rebel 2000's Sigma 300mm lense to see how the pics would come out. Well when i attached the lense the camera powered up fine but when i would go to take a picture the camera would throw an ERROR 99 and shut off....

I thought any Canon camera in the "EOS" line works with any EOS lense? Anybody know why this kept happening?

Maybe one of the electrical contacts on the camera or lens are dirty?

...or the lens might need to be "adjusted". Not sure exactly what Canon does for this, but I've seen some lenses that were released before the 10D (and D-30 and D-60) that required some kind of software update otherwise they wouldn't get recognized, or focus properly.

The only lenses I know that are not supposed to work with the 10-D are the EF-S series lenses, which are the shorter, APS-sensor only ones which were released when the 300D came out.

Here you go. http://iphotoforum.com/forum/viewtopic.php?t=3017

Great link, sucks for me though because i only had use of the camera for a day and this pretty much ruined it. Oh well, i had tried two sigma lenses on the camera to make sure it wasn't a contact or just the one lense being bad or something.

I hope i don't have to have my lenses upgraded when i buy a Digital Rebel...?

Thameth, chances are the same lenses that have the issue with the 10D will be with all newer Canon bodies, such as the 20D and 300D (digital Rebel). Sorry man.

I guess i should send them out now so their ready in the future. I'll have to read up on that link you posted.

Huge Thanx again

Some older Sigma optics have to be rechipped/reprogrammed to work with newer cameras, thus the ERR99, Sigma does this upgrade free of charge if im not mistaken.