Review: Irix 15mm f2.4 Blackstone (Nikon F Mount)

If you were to look at the lenses coming from Korea in the past couples of years, you’d be shocked; and that’s where the Irix 15mm f2.4 Blackstone lens is manufactured. We took a previous look at the company’s Blackstone lenses at Photo Plus last year and were very blown away by some of the features and innovation that Irix has been putting into the glass to make it different from many of the others out there. For starters, besides the metal build, there is text on the lens that can be illuminated to glow when a blacklight is shone on it. Then there’s the fact that the lens clicks into place when the focusing hits infinity. While these features sound infinitesimal, they’re important to the manual focus shooter when it comes to working with a precise manual focus optic in various lighting scenarios.

Then you consider other features such as weather sealing, the image quality, and the feeling of the lens in your hand–and then it just gets put over the top in many ways.

Pros and Cons


  • Absolutely fantastic image quality
  • Not too contrasty
  • Not too saturated
  • Super sharp
  • Zone focusing scale and a touch-up zone focusing scale
  • Weather sealing
  • Smoothing focusing action
  • Click at the infinity spot
  • Illumination with a blacklight in the dark
  • Autofocus confirmation and EXIF registration in the contacts
  • These lenses are pretty damned affordable.


  • Maybe the text on the lens should be glow in the dark and not blacklight illuminated

Gear Used

We tested the Irix 15mm f2.4 Blackstone with the Nikon D850.

Tech Specs

Specs taken from the Irix 15mm f2.4 Blackstone page


The Irix 15mm f2.4 Blackstone lens is pretty gorgeous. When you look at it and hold it, you can tell it isn’t a conventional lens at all. There are amazing things about the lens such as the exterior being made of metal (the detachable lens hood is plastic).

The Irix 15mm f2.4 Blackstone’s front element is weather sealed. As you can also see, there is surely room for you to mount a filter if you need to.

The Irix 15mm f2.4 Blackstone has a unique design. It’s characterized by not one, but two rings. The main ring is the focusing ring. This ring works accordingly with the lens’ depth of field scale. Unfortunately, it only start at f8 instead of something like f5.6 to give a bit more insight into zone focusing. Then on top of the depth of field scale is another scale that gives you some touch ups.

One of the nicer things about the Irix 15mm f2.4 Blackstone is that there is a whole other ring on top of the focusing ring. This ring is the focus lock ring. It ensure that your focusing doesn’t move at all. Twist it to the according lock position, and you’re all set. It’s so incredibly nice and movements in your hand are sometimes bound to turn the focusing ring no matter what lens you’re working with.

Build Quality

Though I didn’t take the Irix 15mm f2.4 Blackstone out in the rain or inclement weather, it surely did survive some tumbles in my camera bag. Still, the Blackstone versions of the lens have full weather sealing vs the Firefly versions which have a plastic exterior and no weather sealing on the front element. With the Irix 15mm f2.4 Blackstone lens, you can rest assured that as long as it’s connected to a camera with weather sealing that it is protected. On the lens mount, you can see the rubber ring that completes the contact with the camera.

The exterior is also made of metal and has a texture that doesn’t really make the lens slippery at all. Instead, it’s easy to grip and hold onto. It’s a great lens when it comes to the build quality.

Ease of Use

If you’re not used to manually focusing a lens, then the Irix 15mm f2.4 Blackstone may be difficult. There is a full depth of field scale as well as a touch up scale on top of the depth of field scale and a nice, hearty click that confirms that you’re focusing at infinity. When it came to street photography, I just needed to ensure that I was focusing and shooting at the right distance away. Many times I didn’t even look through the viewfinder simply because the lens is just that wide. With all this said, I’d recommend that the Irix 15mm f2.4 Blackstone be only used by photographers who understand manual focusing and its intricacies.


Focusing the Irix 15mm f2.4 Blackstone requires you to do it manually. The focusing ring is nice and smooth and there is quite the focusing throw–but it’s not as tough as something like Rokinon’s lenses. To help with focusing, there is a depth of field and distance scale. Zone focusing is perhaps your best bet here.

Image Quality

The greatest thing about the Irix 15mm f2.4 Blackstone is the image quality. Irix has an image quality that they can surely call their own–which I find amazing. They’re not like Tamron, Sigma, Zeiss, Rokinon, Nikon or Canon. They’ve got just a bit of extra saturation, not a whole lot of micro contrast or contrast at all, and some superbly sharp optics.


The Irix 15mm f2.4 Blackstone is inherently a wide angle lens. It isn’t even one of the fastest out there. So getting bokeh really requires you to shoot wide open and get really close to your subject. Your bokeh isn’t going to be glorious, creamy, or incredibly beautiful. But it’s surely going to be more than adequate. The focus falloff however is pretty nice.

Chromatic Aberration

Is there distortion with this lens? Amazingly, not a whole lot. I went through Capture One’s settings with distortion correction and in the end liked the original images better. Of course there is perspective distortion, but you have to expect that. Additionally, you’ll get some lens flare sort of like how you see on the bottom left in the photo above. But personally speaking, I like lens flare. This one looks a bit like a light leak, and I’ll happily embrace that.

Color Rendition

Irix seems to have a color rendition all their own. At times, it seems to be pastel. At other times, it seems to just be a bit muted and subdued. It’s a beautiful color rendition though and with a sensor like the Nikon D850’s, a whole lot can be done with the files anyway.


The best sharpness from the Irix 15mm f2.4 Blackstone comes at f8. But even when you’re shooting it wide open, the sharpness is pretty strong. I’ve got little to complain about here. Is it Zeiss sharp? No, but it’s close. Is it Sigma sharp? It’s probably just behind them.

Extra Image Samples

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  • Weather sealing
  • Image quality
  • Features


  • I’d love some autofocus lenses or a zone focusing scale that works at f5.6.

The Irix 15mm f2.4 Blackstone is a seriously fantastic lens in many ways. It has great image quality–but it doesn’t best Sigma and Zeiss. However, it comes close and in some ways I feel like it can’t be directly compared. But where the Irix lens really earns our Editor’s choice award comes with the features. Let’s list them:

  • Weather sealing
  • Zone focusing scale
  • Touch up zone focusing scale
  • Click at infinity
  • Texture that makes it easy to hold
  • Blacklight glow text
  • Focus locking

Some of these features have never been done by any manufacturer and it gives Irix quite an edge. For this reason, the Irix 15mm f2.4 Blackstone is surely worthy of our highest praise.

The Irix 15mm f2.4 Blackstone wins our Editor’s Choice award and five out of five stars. Want one? Be sure to check out Amazon for the latest prices.

Chris Gampat

Chris Gampat is the Editor in Chief, Founder, and Publisher of the Phoblographer. He also likes pizza.