This was probably the only time this happened so far, instead of the manufacturer approaching me to review a lens, it was the other way around, I requested a review sample of the 17mm F1.7 from Yongnuo. I did so because I was curious about how the new 17mm alternative lens performed and if it can do better than Olympus 17mm F1.8 which I openly talked about how much I disliked its rendering. Yongnuo sent me the lens and I did several street shooting sessions on the streets of Kuala Lumpur on my own OM System OM-1 and Olympus PEN E-PL7 cameras. Long story short, the lens performed admirably, and I do prefer the Yongnuo better than the Olympus 17mn lens. I have made a video to talk about this, you can view it here (click). 

Yongnuo 17mm F1.7 for Micro Four Thirds