[Val.Ou]

I have tried the 15mm three days ago at the Paris Photo Show. Mechanical construction is a fine hight-quality and very clever one, for both the firefly variant , as the blackstone. Optical quality seems very fine too. Very well balanced lens on the K-1, and lightweight. Even the blackstone variant. Amazing lens.
The 11mm-K will be avalable untill 2 monthes in Europe.

[Snappertim]

Just received my Irix 15mm Blackstone yesterday, purchased from the Irix site, order was fulfilled by Lens-Tip of Poland took four days to reach London, lens feels very well made, lock ring is a bit fiddle because its next to the focus ring, comes boxed, inside the box a tin, two rear caps and the hard case, I am awaiting a thin frame Hoys CPL. filter for the front, Instructions tell you to take care in case the filter touches the front element, I will use the standard technique to assess this, and then leave the filter in place, as this is the only 95mm fitting lens I have,
So designed by two Germans (ex Leica ??) for a Swiss company (TH Ltd) made in Korea (Samyang ??) and distribution by Lens -Tip from Poland in europe (the Samyang theory may come from the fact Lens-Tip is the distributor for Samyang - big on Ebay) total globalization, !!!!, I will take some pics with the lens on my K1 and post when I have the time, My plan of use is to hyperfocaly set the lens to about f9.6 (shows in the viewfinder of the K1) and just point and shoot.

[JPT]

This short report has some astrophotography samples taken the the Blackstone version on the K-1. It's in Japanese but the shots might interesting to anyone considering the lens for astrophotography.

irix15?f/2.4 Blackstone | GANREF

[Interspieder]

I guess the lens is slightly decentered, because on the last picture, on the left side you can see way more coma (startrails) than on the right side. Otherwise it looks quite good (imo).
The only real game-killer for me is the flare resistance- or better the non-existance of flare resistance

Otherwise the lens would have been my choice as a wide angle lens.

[wkraus]

I guess the lens is slightly decentered, because on the last picture, on the left side you can see way more coma (startrails) than on the right side. Otherwise it looks quite good (imo).
The only real game-killer for me is the flare resistance- or better the non-existance of flare resistance

Otherwise the lens would have been my choice as a wide angle lens.

Actually what you are seeing in the upper left corner is not coma but the movement of the stars. Depending on the position of the rotational center in the image, varying amounts of star movement are to be expected. Tangential coma is clearly visible in both corners.

@JPT: Thanks for the link!

[OzzRod]

My IRIX 15mm f2.4 Blackstone arrived today, also dispatched from Poland. Interesting metal storage box ("tea cannister"); nice semi-firm zippered pouch; lens cap fits even with hood in place; spare rear cap; basic instruction notes. Lovely looking lens, especially on the K1. Has a focus lock ring that my stubby fingers have a little difficulty moving; focus ring is firm and smooth (with slight click stop at infinity); aperture is controlled in camera.

Took it for a quick spin this afternoon - probably didn't do it justice because I don't have my "eye in" currently for wide shots. My copy is beautifully subject sharp at MFD and infinity, but I've yet to test centre/edge sharpness rigorously; oof backgrounds are rendered fairly well. Nice contrast; colours just a touch on the cool side perhaps; colour fringing seems not be a significant issue; lovely sunbursts; minor multicolour flare features (I quite like them). The only "issue" for me is distortion near the margins but hey, I've only taken about thirty shots and I'm sure I can exert better user control of this. Initial verdict - very happy. My fingers are crossed for decent star images ....

A handful of images with notes here.

[ranchy]

Great to see more owners of the Irix 15mm. do share your shots here too.

https://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/333494-pent...ur-photos.html

[Nitrogliserin]

Does this lens provide hard-stop at infinity? Is it well calibrated?

[Weevil]

If you go to that thread, https://www.pentaxforums.com/forums/122-lens-clubs/333494-pentax-irix-lens-cl...ur-photos.html you'll have your answer:

The focus ring will slightly turn past infinity but has a click stop at the calibrated infinity. I don't own one yet so I can't tell how well the factory calibration is but there is a small access door that can be opened to recalibrate the infinity focus click point yourself and it also has a switch to lock focus at any chosen point.

[Nitrogliserin]

I did and it's a bit disappointment. Same as Samyang...

[Mistral75]

Tested by Jean-Marie Sépulchre on Canon EOS 5D Mark III for Le Monde de la Photo:

TEST IRIX 15 mm F/2.4 Blackstone : Prise en main - Le Monde de la Photo (5 pages in French)

- you need to stop down to f/8 or f/11 to achieve edge-to-edge sharpness
- heavy vignetting
- no visible chromatic aberrations
- very moderate distortion.

[DrBop]

The Irix web site store is set-up as a multi-step process purchase far from Click and Buy.

First you must link to a description of the lens, then Details, then choose your mount, then begin the purchase process.

When I first started this chain, I thought I was in an endless loop -- only seeing the description, which I had already read multiple times!

BTW, the U.S. Amazon.com site shows Canon and Nikon mounts for sale from a vendor based in Hong Kong. No Pentax mount offered.

[Zygonyx]

Canon doesn't seem to be the sweet spot for IRIX.
That's fine for me, as EF mount has the widest choice in lenses...

[Mountain Vision]

I thought it was common knowledge that they have worked together before... I've never heard it contradicted, it you have sources that say otherwise, I'd be interested to know.


For instance, one example:


Pentax DA 12-24mm f/4 AL ED [IF] - Review / Test Report


Eric

When Hoya owned Pentax they shared some lens designs like Tamron does now. Unfortunately, that was the end of Tokina K-mount glass. From that point on I don't believe Tokina made a K-mount Tokina lens.

Before that, plenty of K-mount Tokina lenses, including 2.8 pro zooms. I had 3 of them. All good. All big heavy metal beast.

ATX 20-35 2.8, ATX 28-70 2.8 (still own it), ATX 80-200 2.8. The weakest was the 28-70 which is why I kept it. Resale was too low for a very good (but not exceptional) 28-70 when pentax only sold APS-C the market just wasn't there.
I wish Tokina would make Pentax glass again, but unless the KAF4 really does change things, I don't expect it. Clearly sales of 3rd party lenses just weren't enough to justify tooling for Pentax. The good news is, Pentax makes some good glass.



---------- Post added 12-10-2016 at 04:40 AM ----------

Do you think a front UV filter would help reduce the ingress of water on the firefly?
Just a thought.

I would think it would make it plenty usable in rain, mist, etc. Remember, even a non sealed lens isn't necessarily hydrophilic. Water has a high surface tension (it's why you use soap, not the antibacterial kind, just plain old soap). Water doesn't just drop into every crack and crevice. If only the front element is different, adding another layer of ingress protection, via a screw on front filter should be enough barrier for light rain, snow, sleet, dust, etc.

Personally, if the barrel and mount are sealed, it almost seems the screw on filter was sort of the compromise Irix felt people would make to save $200 or so, and that would be my choice.

[daimonwn]

Is there any sense to change Samyang/Rokinon 14mm /2.8 on this Iris lens? Did anyone compare this two lenses?
Because I have Samyang 14mm for landscape and asto shooting and I like it except next thing: I can't put round filters and take off lens hood, strange mustache distortion.
With Irix 15mm I have opportunity to use filters and rear gel filters, acceptable distortion. Also I like focus ring lock function, infinity click function. But also read that some lenses have bad optical quality with discentered effect. And at /2.8 aperture sharpness in the corner quite soft (Samyang has perfect sharpness all over the frame at /2.8).
So tell me please change Samyang on Irix or not? Thanks!