From Kenko Global Website
“KENKO Teleplus Pro 300 DGX converters are made with precision quality multi-coated optical glass supplied by Hoya Corporation, the worlds largest manufacturer of optical glass. These glass elements were designed to match the optical quality of the prime lens (even at the edges) and telephoto zoom lenses. The optical design of the elements and light path is wide enough not to cause vignetting.
The PRO 300 family are designed specifically to be used with prime telephoto lenses of 100mm or above, such as 300 mm f/2.8 lenses, and work best with telephoto lenses of 200mm to 500mm. The PRO 300 can be used with telephoto zoom lenses as well as prime lenses. However, Kenko does not recommend them for zoom lenses that have a range starting under 50 mm.”
The problem with converters is the image quality, preparing my gear for my South America adventure, adding a 1.4 converter if the image quality remain will be a plus.
I decided to do some tests using a tripod and manual focusing at the same aperture, for all the lenses.
I tested my favorite lens the Canon 24-105 extended range with converter 33.6 - 147mm, I also tested my Canon Macro lens 100mm that will extend to 140mm, and the last one was Canon 16-35mm that extend to 22.4 - 49mm with the 1.4 converter.
I heard great reviews about “KENKO Teleplus Pro 300 DGX converter but I had to make sure that I was getting same image quality using it on my Canon lenses.
I am more than happy with the result, the image quality remained with all the lenses tested, just to give you an example the following cropped tested images using my Canon Prime 100mm macro attached to Canon 5DMarkiii.
Both images were took at f4, 1/13sec, ISO200, process in batch in Photoshop Raw.
The first one was done with only the Macro Lens attached, second had the KENKO Teleplus Pro 300 DGX converter attached. For me that's close enough to put that little converter in my camera bag.
Price is not bad less that $200US at Adorama.
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