Weather-sealed, magnesium-aluminum alloy body, focus lock, filter thread. Compatible with: Canon

You can see sample images here
Designed in Switzerland and manufactured in Korea, the Irix lenses are available in two different versions; the Blackstone with a magnesium-aluminum alloy body and the Firefly with a plastic body. The advantage of the plastic body is that it weighs up to 12%. The manufacturer claims that the Firefly series lenses are the lightest in their class.
Other differences between Firefly and Blackstone versions
The Irix 15 mm f/2.4 is a fast, weather-sealed, ultra-wide-angle lens for full-frame cameras. The focal length is excellent for indoor and landscape photography, and its brightness is also excellent for starry skies and northern lights photography.
The manufacturer has made it easier to focus Irix lenses to infinity. There is a stopper at infinity that keeps the clicking sound when the focus ring is turned to infinity. This is a great feature when, for example, you are shooting in the dark and need to focus at infinity. However, many things affect the infinity position, such as temperature. The infinity adjusted after the factory is not necessarily exactly right. However, the lens can help with this. You can adjust the focus scale yourself, as the lens has a removable cover and an adjustment screw under it.
In addition to focusing, the lens also features focus lock. A feature that allows you to lock the focus at any point without the fear of accidentally turning the focus ring and causing the focus to shift. Once the focus is locked, the focus will not change either way.
Unlike other wide-angle lenses, it is possible to attach a filter to the Irix lens. Either on the nose of the lens, where there is a 95mm filter thread, or on the back of the lens, where there is a place for a gelatin filter.
Specifications: