Reviews

Bird Photography Equipment – Teleconverters for 7D and 5D MIII

June 2, 2012 by Renato 13 Comments

In my previous blog Bird Photography Equipment Lens and filters I compared two telephotos which I use regularly, the 300 f/4 IS USM which is an excellent prime lens, and the 100-400 f/4.5-5.6 IS USM is the best zoom lens commonly used for bird photography.  I also tried the Canon Extender EF 1.4X II and found that the 300 f/4 worked well but the image quality was never superior that the 300 f/4 by itself.

Recently I tried the Kenko C-AF 2X  Teleplus Pro 300 DGX with my Canon 7D and the 300 f/4 lens.  To my utter surprised it worked!  I had read that this was not possible since the 2X raised the f stop by two-stops making it a 300 f/8.   In this particular case this combination raised the f stop to 8, as expected, but the camera was able to focus.  I tested this combination extensively and found that the 7D would focus but only under good light conditions.  But… after some more testing , I found that the 7D focusing system has more sensitive focusing points on the right or left sides of the 19 point AF system.  After multiple test I found that the 7D will focus under all normal conditions with the Kenko 2X by using the Zone AF set to the right or the left sides as show below:

So now I have a 600 mm f/8 lens with autofocus and Image Stabilization. How good is the image quality? Here are two images (cropped) taken at the same distance and you can be the judge:

Dont try this with a Canon Extender, the camera will not focus!

Note: I thought this would be an interesting post since Canon has now priced the new 600 mm f/4 at $13,599.

To top it all, I am now a proud owner of the the new 5D Mark III and it too works with the 300 mm f/4 + 2X Kenko. It focuses perfectly well even at reasonably low light conditions at f/8!  Again Canon says this is not possible..

Here is a shot with the new Canon 5D Mark III at an amazing ISO 8000 and 1/400 sec with Kenko 2X + 300 mm f/4 = 600 mm f/8 AF and IS:

Sword-billed Hummingbird at my garden taken with Canon 5D Mark III with a 300 mm f/4 L IS USM telephoto and a Kenko C-AF 2X  Teleplus Pro 300 DGX.   1/400 sec, f/8, ISO 8000 Focal lenght = 600 mm

Written by Renato
Renato was born in Quito, Ecuador and quickly flew to the USA to learn all about engineering and climbing company ladders. After getting his engineering degree from the University of Minnesota he worked in the Standard-American-Rat-Race-Company for fifteen years. After climbing the ladder to where he could no longer see the ground, he decided to jump off the ladder and migrate south like all normal birds do. To his surprise home did not look like it did when he left as a young fledgling; the towns were bigger, most of his friends had nests of their own, and the countryside was changed. Shocked by all the change he searched for a new life and a new wife. He stumbled across a vivacious young chick who would accompany him inside a volcanic crater to set up a love nest. So, after eight years of nesting inside the crater a new love for nature and birds has sprung a career in environmental conservation and birding tours. Finally this bird has come home to roost!