ePhotozine made a review of the Samyang 7.5mm F3.5 UMC Fisheye Lens. The Samyang 7.5mm is a relatively affordable and excellent quality fisheye lens.
It is a manual focusing lens and its mount does not have electrical contacts so you have to take photos fully manually and without EXIF information recorded to files.
According to ePhotozine the fact of the lens is priced so low at around £240, this fisheye lens represents an excellent value for money for micro four thirds compact system cameras world. It is able to deliver sharp images and has an excellent build quality. It is also necessary to emphasise that with a fisheye lens, it is relatively easy to use manaul focus due to the huge depth of field provided.
This lens produces a 180 degrees field of view and has a minimum focusing distance of 9 cm. The lens mount is made out of metal and it is relatively small with just about 4.83cm protruding out of camera when mounted. The aperture ring is easy to manoeuvre and is divided in half stop increments. If an object is farther than a metre or two it is quite easy to focus lens as at that distance lens can already be set to infinity.
We can find below some sample photos of the review.