Review on YONGNUO YN42.5mm F1.7 II Large Aperture AF/MF Autofocus Prime Lens for Panasonic GF8, GF9, GX85, Olympus E-PL9 Cameras by Steven Lesperance

I'll start with the GOOD sides of this lens. FIRST this lens is also very sharp wide open and HA is minimal. The SECOND focus ring is very smooth with a long stroke for precise focusing when focusing manually. THIRD, it has manual focus override when you're in autofocus mode, although I have to say that in manual focus mode, autofocus is disabled on the lens itself. Now the build quality is plastic, but what else can you expect from a lens at this price point. FOURTH, it has a metal lens mount, which is very unexpected for a budget lens, and a lens cap. Now for the bad. The autofocus hits or misses pretty hard 50% of the time and really suffers in video mode. I've used it on my GH5 which isn't that good initially and also on Olympus which is better. Pulsating BAD! even in good light, sometimes in bad light it doesn't even lock into place (better to focus manually if possible) and it's noisy too! You can hear the focus motor electronics and these are not your normal auto focus sounds, you will also hear a beep along with the focus motor coming from the lens. I've never heard of a lens that ever did this. Despite everything, can I recommend this lens? Absolutely! If you can work around its shortcomings this is a fantastic lens for M43 systems for under $100, it's a steal. general. Regardless of whether the switch is set to manual or automatic, you cannot close the aperture. So be careful if you have a pocket 4k.