The use of a teleconverter is often a compromise that will result in reduced image quality than with a dedicated lens. This teleconverter is no exception to the rule, although it does offer a cost-effective way to gain extra telephoto reach with image quality that will be acceptable for many people.

Sometimes I have to focus my hand, and the auto focus hunts. But the image quality is really quite good and my 250 ml lens now becomes a 350, saving me the hassle of dragging around my larger lenses at least for long-distance photography or things don't move. I do recommend this model.

So far the Kenko AF 1.4 fits my EF and EF-S Canon (55-250 mm) lens as well as my Sigma 70-300 mm. The Auto focus work fine and there is no distortion. All my testing has been in my back yard, birds and other wildlife.

This basic 1.4x teleconverter lives up to expectations. I bought it to expand the reach of my Canon EF-S 55-250mm STM lens while losing only one stop in speed (it would go from f/5.6 to f/8 at 250mm) instead of 2 stops with a 2x extender.

This little 1.4 teleconverter works with my Canon EFS lenses. YAY!! This really let me reach out and capture some nice pics on a recent excursion with my wife. We both have identical cameras and lenses, and this converter made a definite difference while trying to get a little bit closer shots of...

Moving to a 5D Mk. 3, my Sigma 14-28mm Wide EF-S was going to have issues with full frame, until I read about people using the Kenko HD DGX 1.4 teleconverter. Wow, it works amazing well and I now keep it on my Sigma lens ready to go.

I have used this teleconverter with the EF-S 55-250 STM (which is a very sharp lens) and it works well. It retains autofocus at the center on an 80D and it is nearly as sharp as the lens without the converter and shooting closer (which isn't always possible).

Works very well with my Canon 200D and both my CanonEF-S55-250mmf/4-5.6II andCanonEF 70-300mmf/4-5.6IS USM lens.

Works great with the EF-S 55mm-250mm STM, still focuses quickly and has some pretty nice results on a 7D Mark II. Highly recommended.

Works with EF-S lenses but do loose some sharpness.

Well made, snug fit. 4.5 stops of IS on 55-250 STM lets you recover most of the stop of light lost by lower shutter speed. Good for targets that do not move a lot, or in good light. As with all contrast only AF, half press and compose is often needed (or back button focus and compose).