I just received the Kenko 1.4x Teleplus Pro 300 DGX teleconverter. My first impressions can be boiled down to the following:
- Build quality is great.
- Image quality is great.
- Works great with the 1D Mark IV.
- Does not report to the camera that it is there. It even focuses on the EOS 350D, i.e. it report f/5.6, although the actual f number (with teleconverter) is 8.
- Focusing of the EF 100-400mm f/4.5-5.6 IS L with the teleconverter is slightly slower than without the teleconverter.
- 1.4x is not really enough magnification.
I didn’t have a chance to try it out at sunlight, but judging by the performance indoors at ISO12600, it should work great in the daytime in sunshine. However, I am still a bit concerned about bird-in-flight photos. I’ll add a section once I had the chance to try it out for real.
Practical use
I’ve now had some time to play with the Kenko 1.4x teleconverter and my findings are:
1. For birds, I work in TV mode with automatic ISO, so the camera will bump up the ISO automatically when I insert the teleconverter, resulting in more grainy images with the teleconverter attached. I will have to take some photos in AV mode with a fixed ISO, to compare the image quality properly.
2. The image with teleconverter is not as contrasty, and gets a more washed out look.
3. The focusing is fine with the 1D Mark IV, but problematic with the EOS 350D – this is as expected, as only the 1D series can focus properly at f/8. That it focuses in good daylight on the EOS 350D is pretty amazing.
4. With the EOS 1D Mark IV, the focus speed is still not good enough for birds in flight, unless it is something really slow flying, like a gull or similar. Even something as docile as a Jackdaw (Corvus monedula) is too fast, when the Kenko is used.
So, there you have it – unless you shoot only slow-moving birds (or something stationary), and can accept the washed-out colours, this teleconverter may not be for you.



Jesper Broe is a photography enthusiast with more than 10 years experience. He is a full member of the Danish Onithological Association and specialises in nature photography, aircraft and historic photos. Jesper works exclusively in the digital format.
Jesper sells his personal work as limited edition prints and licenses his work for cards, posters, books, calendars etc. He has travelled extensively in Europe and South-East Asia photographing wildlife and landscapes.
Unless you’ve got an f4 or faster lens, you’ll lose autufotos with a 1.4x TC. You need a f2.8 or faster if you’re using a 2.0x. Or you could go out and buy a 1D or 1Ds body
I know that. I have a 1D Mark II and a 1D Mark IV.
Jesper