Using a Kenko 1.4x Teleplus Pro with Canon 40D

[strelleymagpie]

Hi, has anybody used the Kenko C-AF 1.4x Teleplus Pro with a Canon 40D, and were there any problems? I'd like to use the combination along with a Canon EF 75-300mm f/4-5.6 III lens to extend my range for bird and wildlife photography

 

[Box Brownie]

Just a general point that you might have to bear in mind?

At the long end the f5.6 will become f8 with the x1.4 TC . Can the 40D actually AF @f8 ???

I have a vague memory that with the 7D Canon released a firmware update to allow AF @f8

Hopefully those still using Canon will be more definitive with their answers

Edit
The table in this article says no AF @f8

Which Canon DSLR Cameras Maintain Autofocus with Extenders at f/8 Max Aperture?

Some of Canon's DSLR cameras allow autofocus with lenses with a max f/8 aperture. Here's how to tell which ones.

shuttermuse.com

 

[GreenNinja67]

In layman's terms the output will not be good.

I wouldn't bother having tried the same in the past.

 

[ecoleman]

The 75-300 isn’t a very good lens to start with and will only get horribly worse when adding a TC. If I were you I’d save up and get a Sigma 150-600 at some point