Compact Functional lens: 7artisans 7.5mm/f2.8 fisheye features a maximum aperture of F/2.8. The closest focus distance is 0.12m; widely focus within 180 degree. When you use 7artisans 7.5mm/f2.8 on full frame camera, please change the camera into APS-C mode. Ideal Aperture with Twelve Blades and Multi layer Coating: The twelve diaphragm blades are crucial to favorable rendition of highlights in the fore and background. It provides high quality of the transition as well as nice bokeh for the lens, keeping the background intentionally blurred to keep the attention of the observer on the main subject. The multi layer coating can help the visible spectrum from the subject successfully access to lens, preventing the constructive interference from distracting observer’s attention, outputs beautiful pictures without flare. Portable Aluminum Mount: Designed with aluminum-made body and copper bayonet, 7artisans 7.5mm / f2.8 weights as light as 275g, which is portable for your photography. There is also an included foldable hood, which is convenient for your outdoor photography.You can use it on panorama, macro photography, wide angle photography, and mug shot and so on. Price is fixed. Do not trade. Interested can PM me @ 84298110. Thanks.