Focal Length:28mm (42mm: 35mm equivalent)Focal Distance:0.24m - infinityMinimum Focal length:0.3m (3cm with 1:1 Extension Tube Adapter)Max aperture:f/2.8Focus mechanism:InternalLens Length:4cmFilter Thread Diameter:37mmLens Weight:280g (9.8 oz)The SLR Magic 28mm f/2.8 lens is a multi coated manual prime lens that is made to work with the Sony NEX system for camera bodies such as the NEX-3 NEX-5 and NEX-VG10. Lens is in native E lens mount and will work directly on your camera! What is really special about this lens is that it is very light weight (280g) and has a unique rotational aperture disk. When wide open it produces silky smooth bokeh. When stopped down it still produces silky smooth bokeh. It is because the rotational aperture disk ensures a perfectly round aperture opening at all times for the perfect bokeh. It is the signature of this SLR Magic lens. The lens is great for creative photography. A perfectly round aperture is achieved at all times means great portrait photos can be achieved. The fully manual lens is great for creative photographers who would like to take artistic photos with a shallow Depth of Field.