Canon Auto Focus Extension Tube EF 12 II problem

Hi all,

I just got the Canon Auto Focus Extension Tube EF 12 II for my 24-105mm lens. Before purchsing i made sure that this is compatible with the lens and according to Canon it is.

Well, the problem is after installing the extender to the camera body, and then the lens to the extender, i am unable to get the aperture reading it kept saying "00" i can change Shutter speed ( shooting in Manual) on the 24-105mm i have changed the setting to MF and even IS to off.

Am i doing something wrong or is this device not compatible or did i just get a bad copy??

TIA!

You should be able to set the aperture (and also AF) with the extender on.

If it's seated on the lens/body correctly and you're getting an aperture of '00', then I'd say it's a duff extension unit and return it for a new one.

went home during lunch time and I was able to see the aperture. However, i cannot focus AT ALL.

If this is a bad copy then it'll be my first one. i got it from an online retailer. i wish i have gotten it from amazon.com but they are out of stock..

I hope you know that you lose infinity focus with extenders...
Otherwise, clean all the contacts.

I've used extension tubes with my 24-105 before with no problems.

I found it easiest to set the lens to the desired focal Lent, ie 100mm, and switch to manual focus. then just rock back and forth looking threw the viewfinder until you achieve focus.

Eric