Swiss company Irix recently released two versions of their 15mm F2.4 prime to the consumer market. The Irix 15mm is offered in two varieties: 'Blackstone' and the 'Firefly.' The Irix Blackstone features a magnesium and aluminum body able to withstand 'extreme conditions,' while the Irix Firefly model is, according to the company, the lightest lens in its class. Both versions of the lens are available in Canon EF-, Nikon F- and Pentax K-mount. 

The lens is composed of 15 elements in 11 groups and produces a really nice sunstar and some, well, very interesting lens flare. Interestingly enough although the lens states its widest aperture is F2.4, the best we could do on the Canon 5DS R was F2.5. In any case we put the lens to the test over a few weeks of shooting and here are the results. 

Irix 15mm F2.4 real-world sample gallery