EOS 40D + Extension tube + EF-S lens

When I try 40D plus 12mm ext. tube + EF lens it works fine

 

The ext. tube is a no brand 12mm (probably Soligor) with 5 contacts, tried with

several EF lenses with 5 or 8 contacts (besides ground)

 

When I try 40D plus same 12mm ext. tube + EF-S lenes it do not AF and when I

press the shuter the Error 01 appears (...clean the contacts)

 

The ext. tube has been filed (Dremel) to accept EF-S lenses. I tried with

17-55mm and 10-22 lenses. The tube does not seem to have any chip, only straigt

wires from the front contacts to the rear contacts.

 

I can not explain why this is happening. Can anybody help?

 

 

Related with this topic, as said in a previous thread, some e**y Hong Kong

sellers are announcing new Kenko DG tubes that work with EF-S lenses.

I checked manufacturer website and it says NO compatible with EF-S but the

pictures in some of the e**y sellers show a white point besides the red one and

also a big hole so maybe it is true. I mailed one selle, he says the website is

not updated, they received these new ones tubes a month ago.

 

Has anybody tried those new ext. tubes with 40D and EF-S objetives?

They are cheaper that the Canon ones.

 

Regards

Are you setting your EFs lens to wide anngle (18mm?). If so, you won't auto focus with any 18mm lens, EF or EFs. Try move to the long end of the zoom and manual focus and see if at least it will beep. If not, you could have contact issues. PS. Focus with moving the camera back and fore, not the focus ring.

My cheap (Jessops UK) extension rings that AF work OK with my EFS lenses (10-22 & 17-85) on my 20D. I am planning to replace my 20D with the 40D, I hope they continue to work.<div></div>