"The Irix 11mm f/4 is an excellent ultra-wide-angle prime lens that delivers very good image quality. Sharpness in the centre of the frame is excellent throughout the aperture range, even wide open at f/4, as are the edges, with f/5.6-f/11 producing the best results. The Irix 11mm f/4 is a pleasure to use, thanks to its superb build quality, smooth focus ring and hyperfocal scale." Read full review

"What an exciting lens the Irix 11mm f/4 Firefly is. It opens up a whole new world of creative possibilities in a well-made, well-designed package that delivers the image quality. It will not be for everybody, perhaps because of the ultra-wide style of the images, or maybe because of difficulties using the manual focus system, but if the lens appeals to the individual photographer's creativity then it will be a rewarding experience." Read full review

"The Irix 11mm f/4 Blackstone is a well made and competitively priced ultrawide lens for full-frame Canon, Nikon and Pentax DSLRs. Image quality and handling are very good, but if our test sample lens is anything to go by, you may have to make some exposure corrections to compensate for the lens's imprecise aperture diaphragm control." Read full review

"Urban, real estate, and landscape photographers looking for the widest possible focal without fisheye effect should be pleased by this product." Read full review

"Irix came up with an appealing piece of well-designed ultrawide lens. At the time being, it is the widest rectilinear lens available, offering good sharpness, very controlled amount of distortion – and that all in a body that is perfectly weather-sealed (Blackstone version) and built to outlive the photographer." Read full review

"This is a nicely-built and attractively-designed lens that is simple to use and delivers nice image quality at a bargain price. This lens may be the ideal gift for a photographer who seems to have everything." Read full review

"Image quality is very good even on maximum aperture; stopping down improves quality up to f/11. Irix Firefly 11/4 offers  good image quality and features in its price-range (approx. 600€ in Finland)  and features like “Focus lock” and “Infinity click” makes it a solid performer." Read full review

"Through the years i have been able to test different lenses, today thanks to my experiences i can say that the IRIX 11mm Blackstone is a great and unique lens!" Read full review

"When you use the IRIX 11mm f4 Blackstone lens, you’ll realize that it’s pretty difficult to get a bad photo with it. Like pretty much every lens on the market, it’s got good image quality and there is very little to discredit it with when it comes to the image quality." Read full review

"The Irix 11mm is a fully manual lens. Its focus rig is large, well dampened and fluid. Its range allows precise adjustments at close distances, and easy corrections at longer distances." Read full review

"In terms of image quality, I was pleasantly surprised by the optical performance of this glass. The sharpness in the center is very good even at the widest settings, while the corner resolution improves significantly at f/5.6. Have a little bit of Vignetting and chromatic aberration at f/4 but they also decrease when stopping down the aperture." Read full review