Review on YONGNUO YN2 0X III Teleconverter Extender by Joseph Cvetkovic

. This worked great with my Canon 80D and Canon EF 70-200 F4. However, I've only used it twice, taking about 200 photos in total. On the third try to use it I got "Er 01, there is a problem with the camera and lens communication. Clean the lens contacts." The contacts looked great and I tried cleaning them to no avail. This was a real bummer as I really needed the extra range in the event I was shooting at. The teleconverter stopped working properly during the warranty period, but when I contacted the seller it was out of warranty. They couldn't help and told me to contact Yongnuo directly. I've messaged Yongnuo to see if they can help at all, but their website states that warranties only apply to items purchased directly from their website. If I get help from them I will update the rating. Overall it worked as expected and I managed to get some great photos with it the two times it worked. However, had I known I was going to have problems with that, I would have just gone for a Canon teleconverter, no matter the price. I can't get the photos I missed from this third event.