The K & R Concept Lens Mount Adapter for Nikon F mount lenses to Micro Thirds camera bodies does exactly what it was designed to do. I have tested it with a Blackmagic Pocket Cinema Camera using Nikon glass, both an AFS DX 55-200mm f4-5.6G and a 50mm f1.8D. Both worked.Since the 50mm f1.8D has an aperture ring, you can use the adapter or the aperture ring on the lens to control the iris function. With a Nikon "G" lens, you must use the adapter to control the iris. If there is a downside to the adapter, it is that there are only six clicks between wide open and stopped down and there are no markings to indicate the correlation between the adapter's clicks and the lens's F stop. Having read a previous reviewer's comments, I was aware of this, however, so it was no surprise. The BMPCC has a histogram, so that can be used for exposure metering. Previously, I have used a Nikon 50mm f1.4 non-AIS on a D5100 body. With that set up, there is no exposure metering either. You can check exposure by eye through live view or use a light meter.So, if you absolutely need to know the F stop value you're shooting in, then this adapter is not the one. Certainly a Metabones Speedbooster is a better option as it is calibrated and clearly marked - the caveat being that it is also significantly more expensive. If you're comfortable using additional tools to check exposure or don't mind eyeballing it, then this is a great value for $16.99.