f = 8mm F 2.8 For 2/3 type Cameras C‐Mount Model No. M0828-MPW3 Effective Front φ21.2mm Focal Length 8mm Lens Aperture Rear φ10.1mm Max. Aperture Ratio 1:2.8 2/3 type(Y=5.5mm) -1.80% Max. Image Format 8.8mm x 6.6mm(φ11mm) 1/1.8 type(Y=4.5mm) -1.68% Operation Range Iris F2.8 ‐ 16.0 1/2.5 type(Y=3.55mm) -1.28%