Err 99 message on 350D

[Macone]

Currently having problems with my sigma 100-300 lense on my canon 350d. When the appeture is set any higher than 4.5, i get the message err99 and the camera then locks up.

I'm thinking it could be to do with the lack of power for the lense, although the battery is new and fully charged.

I would be gratefull of any ideas.

[Rhys]

Never tried it but it sounds like the lens is slightly incompatible. Ask Sigma, if it's a new lens. Otherwise either change the lens or the camera for a different model.

[noyjimi]

Can't hurt to try: Clean the lens contacts by gently rubbing with a pencil eraser. Make sure the dust doesn't get into your lens or body though.

[Macone]

Thanks for the advise. It looks like the lens may not be fully compatible with the camera as suggested. If i use the creative modes the lens seems to work ok, as long as the aperture is kept large. I seem to have the problem when i use the manual modes.

Thanks again.

[coldrain]

Your Sigma lens is quite a few years older, right? The signals from the lens are not totally accurate and give problems with bigger apertures, same as my old (and AF broken) Sigma 70-300. It is a known problem with older Sigma lenses.

[Macone]

Thanks Coldrain, your correct. I originally got the lens about 5 or 6 year ago, to go with my Canon 3000. That camera also locked with the same message, but only the once. It was a cold day on the top of a high rise block of flats, i put that instance down to the cold weather draining the power. It looks like i may have to invest in a new lens. Thanks for you help.