bought the adapter because I also want to use my existing Nikon lenses on the new BMPCC4K. Because the vast majority of lenses have an aperture lever, they can also be used without a separate aperture ring (lenses without E-marking!) The adapter makes a very high-quality impression. It is made of metal and fits comfortably in the hand. It can be easily connected to the camera and lens. I haven't been able to find a game yet. If this occurs during use and possibly leads to stray light, I will provide an update. The adapter is supplied in a small plastic box. This makes it easy to store or transport when not in use. The silver ring is used to adjust the opening. However, there are no numbers to be found, only a symbol for open and one for closed aperture. But you can see directly on the display how turning the ring affects the brightness. So I'm not missing any numbers. I have also read from other adapters with numbers on the ring that these values are not as finely graduated as the numbers make it seem, I am very satisfied with this adapter. Of course you lose light intensity because any mounting between the lens and the sensor “swallows” light. But this adapter only costs a fraction of what a speed booster costs. Moreover, you don't get a speed booster with contacts for Nikon lenses. No information is passed to the camera, so you have to set everything manually, even if you use a speed booster. I highly recommend this adapter to anyone who can tolerate a bit of low light.