I haven't had the full use of this extension, but I like it so far. I use the extender on a Canon 70-200 f2.8 ISM lens with no autofocus issues. I used f8 as most reviews said that was the "sweet" point. I do a lot of school sports photography. If I make more I will update this review. I have attached some photos. I think the labels speak for themselves, but basically I took the same shot at 70 and 200 and then added an extender for the 140 and 400 shots. So it seemed like the photos weren't added in the right order, but I think you can see the difference. Update: I was able to use this extender today while photographing a local high school football game. WOW! Added two more photos. Image with target in focus at 120 yards at f8 and ISO 2000 at 400mm. There were absolutely no problems with autofocus and slowdowns, as in many other reviews. I shoot with Canon 5D Mark IV and Canon 70-200 f2.8 ISM. I know it was 120 yards because the game was played on a soccer field and the goal was at the end of the end zone, 10 yards on each side, 120 yards total. The image with people in focus is about 100 meters away. I highly recommend this product to anyone who needs extra lens distance. Be sure to check compatibility with your lens.
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