Seven reasons Irix may be the greatest budget ultra wide lens for Milky Way photos

What is a good lens for Milky Way photos that won’t break the bank?

This is a common question that frequently pops up in social media discussions everywhere. People ask about recommendations for ultra wide angle lenses for night photography, astrophotography, or photographing the starry night. And with “Milky Way season” upon us, I thought I would mention a high quality option that I use.

My “workhorse” night photography lens is currently the Pentax 15-30mm 2/8 lens. This is the same lens as the Tamron 15-30mm f/2.8 (Tamron makes it for Pentax). It’s a high quality lens. However, it is also almost $1300 in price. Not everyone can pay that much for lens. 

However, there’s another lens that I use right without hesitation that works extremely well!

Irix 15mm f/2.4

My often-used Irix 15mm f/2.4 ultra wide lens, still going strong after quite a bit of use.

I was one of the first people in the United States to purchase an Irix 15mm f/2.4. In fact, I purchased it in 2016, so early that Irix didn’t have distribution in this country! I had to purchase it through eBay. But I was glad I did.

I have the Blackstone version of this lens (more on this later), which is a sturdy manual focus lens that almost seems made for night photographers, although I believe it would  be a good lens for long exposure photography, landscape, architecture, or real estate as well.

Seven reasons why I love this lens

1. Sharpness even at wide apertures

Even at its widest aperture at f/2.4, it’s surprisingly sharp. Wide open, of course, there is some vignetting in the corners, which is easily addressed. There is slight softness in the corners, less than most ultra wide angle wide-aperture lens.. And the time you stop down to f/2.8, everything seems tack sharp.

Ojo Oro Arch, a remote arch deep within the Mojave Desert, a Milky Way photo taken with the Irix 15mm f/2.4 lens.

2. Detent at true infinity

Move the focal ring and you will feel a detent at true infinity. For photographing the Milky Way or the starry sky, this is invaluable. Just fix the focal ring at detent, and you are ready to go. 

But there’s more. If a foreground is not quite in focus at infinity, you can simply re-focus the lens for the foreground object and then “focus stack” the two photos later in post-processing so that everything is in focus. And this brings me to the next point….

3. Scarcely any focus breathing

There is very little “focus breathing” when re-focusing as described above, having elements grow larger if one is refocusing. The entire time I have been focus stacking with this lens, I have never encountered an issue. It blends beautifully.

4. Rectilinear distortion

For a wide angle lens, the Irix exhibits very little barrel or pincushion distortion. It’s a rectilinear lens, so images with straight features, such as walls of buildings, continue to appear with straight lines instead of being curved. 

5. Accepts filters easily

Most ultra wide angle lenses have bulbous front elements. Not so the Irix. This allows it to accept screw-on filters in the front. Furthermore, it also accepts gel filters in the back. This would make it useful for long exposure photography without the need to use externally-mounted and more expensive filter systems such as Nisi, Lee or Cokin.

6. Inexpensive

TheIrix Blackstone, which a sturdy all-metal model which I have, sells for about $549. The Firefly, which is basically the plastic version of the Blackstone, sells for under $400. You can purchase three Firefly lenses for the price of one Tamron 15-30mm f/2.8 and still have enough money left over to purchase a speedlight….or dinner for four at your favorite Mexican restaurant. Mmmmmm……tacos…..

7. Focus lock

How many times have you, as a night photographer, mistakenly knocked the lens out of focus? Raise your hands. We’ve all done it, haven’t we? I often affix gaffer’s tape to the focus ring of my other lenses. I don’t need to with the Irix. The focus ring is appropriately stiff, and it also has a focus lock. I don’t bother using this if I am focusing on infinity since it has a detent there and is unlikely to be knocked out of focus.


The Irix 15mm f/2.4 Blackstone ultra wide lens also comes with a nice case, a soft case which is still firm enough to offer ample protection.

There are few ultra-wide lenses, if any, that can approach the optical quality of the Irix for this price, or even several hundred dollars more, for that matter. The one lens I can think of off the top of my head that one could also consider in the same price range would be the Rokinon ultra wide angle lenses. 

The Irix also has UV Fluorescent Engraved Markings. I was excited about this upon purchase. In practice, however, they don’t seem to be all that visible at night. And I probably wouldn’t use it that much anyway, preferring to manually focus on sight. Still, the fact that the engineers even thought to incorporate this indicates how much they seemed to be designing this lens for night photography.

As I mentioned, this lens would be outstanding in many applications, including landscape, architecture, real estate, and long exposure photography. But isn’t it good that a night photographer is looking out for your needs all the same?

Ancient Bristlecone Pine Forest, California. Irix 15mm f/2.4 lens.

Final words

While I haven’t done a specific side-by-side comparison with the 15-30mm f/2.8 lens that I have, I have alongside or instead of that lens without hesitation for years. And I’ve never felt like I’ve ever perceived a drop-off in image equality or sharpness at any point. It keeps up with that or the venerable 14-24mm f/2.8 F-mount without breaking a sweat. And given that the Firefly version is under $400, less than a third of the price of those other lenses, that’s stunning.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s