Conclusion

The Irix 45mm F1.4 GFX is one of the fastest native GFX lenses on the market, and shooting at f/1.4 on a medium-format sensor is certainly an addictive drug - when the focus is spot on, the degree of separation that's possible between subject and background is intoxicating.

On the flip-side of that shiny coin, actually trying to get the subject sharp is certainly a challenge with this lens, given its manual-focus only nature. Despite the best efforts of Fuji's excellent focus peaking and auto-magnification visual aids, shooting at f/1.4 on such a large sensor camera inevitably results in a lot more misses than we're used to, whilst also slowing down the overall operation of camera and lens in order to try and achieve more hits.

That's perhaps an unfair criticism of this particular lens, which applies to shooting with very fast glass on any camera system - what's more problematic for the Irix 45mm F/1.4 GFX is the actual image quality that it delivers.

It seems that the design and optical construction are actually identical to the 35mm DSLR version - Irix have essentially just adapted it for G-mount and added a physical aperture ring in place of the electronic contacts that provide some degree of automation on the DSLR version.

This means that the optical construction of this lens only just covers the larger Fuji medium-format sensor, which results in rather severe vignetting that only disappears at f/8. There's also plenty of chromatic aberrations and flare when shooting directly into the sun, although thankfully Irix's promise of less than 1% distortion is at least borne out in practice.

It's also not the sharpest lens that we've ever tested - whilst centre sharpens is OK at f/1.4 and impressively high throughout most of the rest of the aperture range, edge sharpness is not so good, with the lens requiring you to stop down to f/4 to produce its optimal sharpness.

Build quality is better, with a premium finish and lovely focus ring that belies the budget price-point, although we're not huge fans of the lock ring which doesn't truly lock the focus ring into place.

Another factor to take into account is the size an weight of this lens - it's a lot bigger and much heavier than its main rival, the Fujifilm GF 45mm F2.8 R WR, which also has the obvious advantage of having auto-focus.

Fuji's 45mm does cost twice as much, however, and has the even more obvious disadvantage of only having a maximum aperture of f/2.8, which is still pretty fast for a medium-format lens, but not on the same level as the Irix 45mm.

And therein lies the main appeal for us of the Irix 45mm F1.4 GFX - it's a relatively cheap and uniquely fast lens that is capable of delivering compelling bokeh and subject/background separation, albeit with quite a lot of manual labour on your part, both to actually carry it and to achieve pin-point focusing and accurate exposure.

Despite the rather obvious image quality issues, overall we're inclined to give the Irix 45mm the benefit of the doubt, simply because there's no other lens quite like it for Fuji's GFX camera system.

Ratings (out of 5)
Design	4
Features	3
Ease-of-use	3
Image quality	3
Value for money	4.5