# Review: Irix Firefly 15mm f/2.4 by Northlight



## Canon Rumors Guy (Dec 13, 2017)

```
Keith over at Northlight Images has completed his extensive review of the Irix Firefly 15mm f/2.4 lens. We seem to have an abundance of fast ultrawide lenses to choose from now. Canon, Sigma, Rokinon, Zeiss and now IRIX all offer competent lenses at different price points.</p>
<p>The Firefly version of this lens has a lower build quality than the Irix Blackstone 15mm f/2.4, which Keith touches on.</p>
<p><strong>From Northlight</strong></p>
<blockquote><p>Optical performance is crisp and with good detail once you stop down a bit. My rough and ready testing suggests that on my 5Ds, f/6.3 or 7.1 give the best overall performance. That said if it’s a central subject the f/2.4 setting restricts DOF enough to soften the background for closer subjects. The amount of coma at the widest aperture may be an annoyance for astro photography, but it’s on a par with many other wide lenses I’ve looked at.</p>


<p>If you’re not used to it, then manual focus definitely will take some getting used to, but after a while you rarely need to give it too much thought.  Modern DSLR viewfinder focus screens are pretty poor for manual focus, so even with a focus confirm indication, your distance estimating skills will improve too. <a href="http://www.northlight-images.co.uk/irix-15mm-lens-review/">Read the full review</a></p></blockquote>
<p><strong><a href="https://www.bhphotovideo.com/c/search?Ntt=irix%2015&N=0&InitialSearch=yes&sts=ma&Top+Nav-Search=&BI=2466&KBID=3296&KWID=EZ">Irix lenses are available at B&H Photo</a></strong></p>
<span id="pty_trigger"></span>
```


----------



## infared (Dec 14, 2017)

Looks like a beautifully designed exterior and not much else. I will keep my $749 Rokinon SP 14mm. THANKS.


----------



## keithcooper (Dec 14, 2017)

infared said:


> Looks like a beautifully designed exterior and not much else. I will keep my $749 Rokinon SP 14mm. THANKS.



Unduly harsh - I've tested both and sure the rather more expensive Samyang is better in some respects.

The Irix exhibits slightly less barrel distortion, so for my (daytime) work is actually easier to work with.

http://www.northlight-images.co.uk/samyang-xp-14mm-f2-4-lens-review/

As with all such lenses you pays your money... ;-)


----------



## Viggo (Dec 14, 2017)

I asked my local shop (very skilled people) about the Irix, and they said they wouldn't sell it to me, and were going to return them all due to the flimsy and inconsistent build quality and absolutely brutal vignetting.

Does any one have a comment about this? Was there a bad batch, or shouldn't one expect much or how come there's such a split verdict on it?


----------



## keithcooper (Dec 14, 2017)

Viggo said:


> I asked my local shop (very skilled people) about the Irix, and they said they wouldn't sell it to me, and were going to return them all due to the flimsy and inconsistent build quality and absolutely brutal vignetting.
> 
> Does any one have a comment about this? Was there a bad batch, or shouldn't one expect much or how come there's such a split verdict on it?



Well, the one I had (from a seller, not the Mfr.) did not have vignetting I'd remotely describe as 'brutal' (see the pics in the review). 

Obviously with just one lens I can't comment on consistency - check other reviews, particularly ones who do rather more of the 'detailed testing' than I have patience for ;-)

I should be getting an 11mm f/4 soon to try as well, and will give it a very good look-over in this respect.


----------



## infared (Dec 14, 2017)

keithcooper said:


> infared said:
> 
> 
> > Looks like a beautifully designed exterior and not much else. I will keep my $749 Rokinon SP 14mm. THANKS.
> ...



I am using my Rokinon mainly for astro...but the lens is a steal at that price ($749) for the build and performance for most genres of photography. Check out Dustin Abbott's review of the Rokinon, the distortion is no big deal. The vignetting is the biggest "issue" but it is inherent on most lenses this wide and I personally do not find it to be a deal-breaker at all. Dustin didn't either. Incredible lens for the money as far as I am concerned. Its even better than the $1500 Sigma 14mm ART optically for astro.
This Irix does not get sharp across the frame until f/6.3. I would not buy it for $100. If I have a 5DIV (which I do) and I am serious about photography (the camera body alone shows that), why would I buy a 2.4 lens that does not get sharp until f/6.3???? For a little more money I can have the Rokinon SP and it is sharp across the frame at f/2.4. (especially useful for my astro pursuits, but useful in general), allowing me to capture clear, beautiful images on my expensive, competent sensor. Why would I severely cut my options with this underwhelming lens...for any price. With the time and energy alone we put into creating images why would I shoot my self in the foot like that? To save a couple hundred dollars? ???


----------



## photoin.nyc (Dec 14, 2017)

Just a few thoughts on this lens. Hope it helps.

I've been using this lens since around May 2017 and it works well. I shot some astro, architecture, and landscapes with it. 
Vignetting is present, but you have to keep in mind that it's a 15mm lens. I also had the Rokinon 14mm f2.8 and I can tell that the Irix has way less vignetting than the Rokinon while Rokinon is better at coma. 

Overall the lens is awesome but, there's one thing nobody talks about, or at least I haven't seen any review mentioning it, and it's a pretty big deal:
The filter thread on the lens is plastic!

It's just a pain to put a filter ring on and after a while it's starting to worn out and it needs a lot more care to avoid extra damage. 
I haven't tried their filter system yet (they came out with square filters), so I don't know how well it works on the Firefly. 

I sent them an email about this issue, but haven't received any response.


----------



## keithcooper (Dec 14, 2017)

infared said:


> keithcooper said:
> 
> 
> > infared said:
> ...



That would be why I emphasised (Daytime) and linked to my own review of the Samyang lens. Living in a big city means Astro uses are somewhat academic :-( The Sigma (at a mere £1000 more than the Irix) would get my vote for quality -and- AF

The Samyang is a very nice lens, but having tried both Samyang and Irix, there is nothing like (for myself) the obvious differences you see from just having used one of them.

Personally I'll likely stick to my Canon 11-24 F4L for my day job... ;-)


----------



## Viggo (Dec 14, 2017)

keithcooper said:


> Viggo said:
> 
> 
> > I asked my local shop (very skilled people) about the Irix, and they said they wouldn't sell it to me, and were going to return them all due to the flimsy and inconsistent build quality and absolutely brutal vignetting.
> ...


----------



## tron (Dec 14, 2017)

From lenstip:

https://www.lenstip.com/486.8-Lens_review-Irix_15_mm_f_2.4_Blackstone_Vignetting.html
8. Vignetting

At the maximum relative aperture it amounts to as much as 72% (−3.64 EV) and deserves to be called monstrous.


----------



## Viggo (Dec 14, 2017)

tron said:


> From lenstip:
> 
> https://www.lenstip.com/486.8-Lens_review-Irix_15_mm_f_2.4_Blackstone_Vignetting.html
> 8. Vignetting
> ...



Thanks, that's pretty much in line with what my shop told me from there testing. 3,64 stops, wow...


----------



## keithcooper (Dec 14, 2017)

tron said:


> From lenstip:
> 
> https://www.lenstip.com/486.8-Lens_review-Irix_15_mm_f_2.4_Blackstone_Vignetting.html
> 8. Vignetting
> ...



I saw this and wondered just how they tested it - I've quite a few shots taken with it wide open, and whilst it's very noticeable at f/2.4, it doesn't seem nearly so bad as those numbers suggest - easily fixable, even without a profile in ACR. I can see that if you expected to be using it wide open very often, such as for astro use, this would be significant. For star photos, there are better choices - but for 'normal' daytime use f/2.4 is not something I'd expect to use very often if at all. In particular if I wanted narrow DOF from shooting wide open, I'd want AF.

Guess it helps explains some of my preference for not buying lenses just on the 'numbers' ;-)


----------



## infared (Dec 14, 2017)

keithcooper said:


> infared said:
> 
> 
> > keithcooper said:
> ...



Well..again....of course, the Sigma f/1.8 ART (very good for astro) and the Canon 11-24 f/4 (not so good for astro) are incredible lenses with AF....and very expensive. No doubt. I do use my Rokinon for other photography, and do own an lot of expensive L and ART glass, but I wanted to get a great astro lens...and it is the BEST super-wide lens for astro at this time, to my knowledge (of any dollar amount)....but as an all-rounder for the price its a great choice, too...As I am sure you know, for the incredible depth of field in a lens like this, AF can become less critical for many every day situations (compared to a normal or tele manual focus lens), so its a very reasonably priced lens for what it delivers and can be used very safely during the day :-X. ..but everyone's needs are different. I do have the Canon 16-35mm f/2.8L III so my Rokinon 14mm f/2.4 SP lens complements my lens quiver perfectly and economically and gives me that extra wide reach if I happen to need it for lots of photography situations, while satisfying my astro needs. One thing for sure we definitely have a lot of choices in cameras and lenses these days. The Irix never made it on my list when I was researching my purchase, mostly because of the build, bad coma, and lack of sharpness wide open. It does come in a cute little well-designed box, though! 8)


----------



## ahsanford (Dec 14, 2017)

Viggo said:


> I asked my local shop (very skilled people) about the Irix, and they said they wouldn't sell it to me, and were going to return them all due to the flimsy and inconsistent build quality and absolutely brutal vignetting.
> 
> Does any one have a comment about this? Was there a bad batch, or shouldn't one expect much or how come there's such a split verdict on it?



The Blackstone version of this lens (presume same optics, just different packaging) shows -3.64 EV Vignetting wide open:

https://www.lenstip.com/486.8-Lens_review-Irix_15_mm_f_2.4_Blackstone_Vignetting.html

...but the 16-35 f/2.8L III @ 16mm f/2.8 _is even worse and it sells just fine_:
https://www.lenstip.com/493.8-Lens_review-Canon_EF_16-35_mm_f_2.8L_III_USM_Vignetting.html

Or you can see both at TDP here:
https://www.the-digital-picture.com/Reviews/Lens-Vignetting-Test-Results.aspx?FLI=0&API=0&FLIComp=0&APIComp=0&Lens=1129&Camera=979&LensComp=1073

I'm not sure a store should stop carrying a lens for vignetting reasons, but it's up to them. 

But as far as this Irix goes, for wide open use it has so-so coma, not terrific sharpness and fairly difficult vignetting. I'm not the astro shooter this lens was designed for, but on those three metrics alone, there clearly are better options out there for you.

- A


----------



## keithcooper (Dec 14, 2017)

The issues raised in the comments here are interesting in the way they show that you ideally pick a lens for the work you want to do with it.

I've gone back and measured a number of shots I took at f/2.4 and it is significant, but still quite fixable in ACR.

I'm partly going to pin it on the size of the front element in this particular design, which does seem small, given the size of the front of the lens.

Unfortunately, the lens has gone back, so I've not had a chance to check the filter thread issue mentioned. I had a polariser to try with the lens, but only used it a few times. I'm just not a big filter user at wide angles (the new big filter system was not available to try at the time I received the lens).

Not sure when the 11mm is turning up - I'll be interested to see how it compares with the likes of my 11-24.

That said, I'm the first to admit that I simply don't have the patience to do much detailed lab type testing - it's about what you can do with a lens for me ;-)

BTW, if anyone has any specific questions about the 11mm, drop me a line at Northlight and I'll try and check when it's here.


----------

