Bower MC4 2X AF Teleconverter for Canon EOS EF lenses

Excellent bang for the $$. Using it with my Canon EF 70-200 mm f4 L the auto focus works fine which surprised me from what some of the reviews indicated. The uploaded photo of the hummingbird was 15 ft away on Auto focus! The ants at pixel level on the bird feeder were very sharp on my monitor. However the edges of other images did have some edge softening on my Canon EOS 30D. On a full frame camera I can see this may be a huge issue. Overall very satisfied.Update: I just received my Canon EOS 5D mk2 and with the same lens mentioned above does show a "ton" of softening with the teleconverter. So I'll not be using it on my full frame camera.

Seems to work well with auto-focus as long as you have enough light. With this on my 70-300mm Canon lens, I can get really close to things without really getting close! Of course, when you're talking about 300mmx2 (as you get with this teleconverter), you really should be shooting with a tripod most of the time. Just be aware that if you get into too low light of a situation that auto-focus will "search" and not be able to lock. In that case, just simply switch to manual focus and fire away!Works as I expected it would. Bower makes pretty good stuff, and I love the extra range this gives me with my Canon 7D.

This lens doubler is perfect. I recently bought the canon rebel t3 when it went on sale along with the 55-250 lens and the 75-300 lens. this doubler is attached to my 75-300mm lens and will not be removed. i tried this at the zoo and got some really beautiful up close shots of a snakes scales that my 55-250 lens couldn't pick up. there is an autofocus issue at max zoom but as i don't own a dslr to have it do the work for me this was not an issue for me for those who do not have experience with manual focus or know how to use it even should not consider this and should instead get the canon version for 3 times the price so the auto focus will work the way you want.

First off let me say that South Bay Camera handled my order very well. I really chose a teleconverter based on price. With that in mind I am very satisfied with the product. I confirm what other reviewers mentioned that the AF "hunts" for a focus at higher magnifications so I had to use manual focus. Other than that, I had no other problems with it. FYI, I used the converter on my Canon 75-300mm f4-5.6 III and my kit lens (18-55mm). It worked on both.

Because it was combatively inexpensive, I decided to take a flyer on this. I slapped it on my 70-300 Canon EF lens and it worked well. I took several photos in a wooded, cloudy setting and was pleased with the results. I'd recommend it if you're looking to double your focal length. Remember, though, it will also halve the shutter speed or f/stop.

Thanks to all who previously wrote reviews listing information about this lens converter for Canon EOS digital. I really needed and wanted a 2x converter for my Canon Rebel XT to use with my 75-300 telephoto lens. I got conflicting information prior to coming to Amazon site. Previous comments really helped!! I am very satisfied with this product. Like it stated you have change two f-stops - but hey - using the camera on manual is the only way to go. The converter is auto-focus so no problem. Great photos!! Bower is a local company in the USA with products made in Japan, what else is new.!! Thanks!!

Fairly sharp photo using 2x converter w/canon 75-300. AF does not stop with subj. in focus. Manual focus only. Also must have lots of light or iso will be high and picture noisy. For the money I won't complain--the review I read before purchase indicated AF would work with the T5 and this lens, thus my lower rating.

I used this to replace the Canon branded converter that got stolen and this one does not like to auto-focus as quickly as my Canon brand did. You get what you pay for, but it does work. I use manual focus to speed things up.