This neutral density filter can be easily installed (as opposed to Delamax gray filter, I had to send back), comes with a lens cover (good because the parts disappear forever once anyway) and makes the picture even darker. The factor is about 4 full stops (3.5 levels in several tests). So if I had to expose an object with f5.6 f1.8 I can illuminate with it now. Why is this good? First, I can play a lot more with the depth of field and when it is very bright outside and I had to, for example, exposure to f18 I then f5.6. A sharp image with F18 should get is purely physical (ray diffraction in the lenses) difficult. With f5.6 very good. 5 stars only because full 4 levels were promised and the filter is not quite just.
