The optical construction of the Samyang 8mm T3.8 Fish-eye CSII DH VDSLR (Video DSLR) DH lens is based on the 8mm 1:3.5 Fish-eye CS model, and is specifically developed for shooting and video with APS-C sensor digital SLRs and professional camcorders fitted with corresponding mounts. This CSII version features a removable lens hood (DH), but is otherwise identical (optically and mechanically) to the standard version with a fixed, non-removable lens hood. The Samyang 8mm T3.8 fisheye lens has an aperture of f3.5 (indicated as T3.8, which is the f-number of a lens corrected for light loss during transmission through the lens). T-numbers are important in the film industry, where TTL metering is not common, and also help to distinguish this video version of the lens from the standard Samyang 8mm F3.5 fish-eye version. Optically, they are identical, with 10 elements in 7 optical groups, one aspherical lens element and multi-coated optics. The features of this new model include geared rings compatible with professional gear-driven follow focus systems used in the film industry, as well as a de-clicked aperture ring with smooth, stepless adjustment. These modifications allow extremely precise control of focus and aperture during video recording/shooting. This enables ultimate manual control of exposure when shooting scene by scene with different light source intensities, such as changing exposure values (EV) from indoors to outdoors, or even in-camera fades, etc. It can also be perfectly used for still photography; however, users may find the standard version with a clicked aperture (Samyang 8mm F3.5 fish-eye) perhaps more suitable to avoid accidentally changing the aperture between shots. The Samyang 8mm T3.8 fisheye lens is a manual focus lens and offers a very large depth of field. The 8mm T3.8 fisheye features a removable/detachable lens hood for shooting on full-frame cameras in order to produce the widest possible image circle. On full-frame cameras with the lens hood removed, it produces a vignetted, almost circular image. This effect is required for users wishing to obtain the largest possible image/field of view for panoramic software on full-frame cameras, and this is one of the specific reasons why Samyang produced this removable lens hood version. The Samyang 8mm fisheye lens is ideal for creating 360° panoramas and virtual tours, including full 360-degree images with appropriate equipment and various third-party panoramic software provided by other suppliers. Available in 10 camera mounts: Canon, Canon-M, Nikon, Pentax K, Sony A, Sony E, Four-Thirds, MFT, Samsung NX and Fujifilm X. The Samyang 8mm fisheye lens offers some of the best optics in its class, with an excellent price-to-quality ratio. A specialised and affordable lens for every videographer or photographer, particularly suited for panoramic and video use. specifications