New Old School Wide Angle For Pentax

smoke665

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So recently this add has been popping up on the Pentax site. Basically a full manual k mount lens, that looks interesting. $599 (metal version) full weather sealed, f/2.4. Can't seem to find much user feed back. Anyone know about it or used it?

Irix 15mm f/2.4 Blackstone Pentax
 
@petrochemist the details I saw on it looked to be well made. If the comparison on distortion that I saw is correct I see all sorts of possibilities for the this.
 
@Derrel I've noticed several posts like yours today where the only thing showing is the post you quoted. Is there a site proble?
 
I believe that this lens was discussed here on tpf, about a month ago, and that western guy mentioned the lens suffered from bad coma, thus making it a poor choice for star photography.

Seems to be some weird problem posting to TPF for me today.
 
@Derrel I'll search that tonight, thank you.
 
Ain't Google wonderful?

I'd already seen a couple of these, but still enjoyed reading the others. Thank you. I'd hoped maybe someone on here had personal knowledge, as I'm always a little hesitant of sites that generate their income from ads of the manufacturers they are reviewing.
 
yeah...this lens is NOT a good ultra-wide lens.

Irix 15 mm f/2.4 Blackstone review - Coma, astigmatism and bokeh - LensTip.com
Bad coma….worse than the much lower-cost Samyang 14mm f/2.8 lens

Irix 15 mm f/2.4 Blackstone review - Vignetting - LensTip.com
"As a result you get one of the highest vignetting values we’ve seen in our tests so far. At the maximum relative aperture it amounts to as much as 72% (−3.64 EV) and deserves to be called monstrous. The f/2.8 aperture is equally weak, with a result of 66% (−3.10 EV). Even by f/4.0 you still deal with a high level of that aberration as it gets to 48% (−1.87 EV).”


Ummm, yeah….that’s the MOST vignetting Lenstip’s testing lab has **ever** encountered. And closed down to f/4, there is still over one and two-third stops’ worth of light fall-off?


Irix 15 mm f/2.4 Blackstone review - Ghosting and flares - LensTip.com

“According to our expectations the situation is not exactly rosy. The flares are distinct, they appear in different combinations of settings and often they are able to spoil the frame completely.”


Ugggh! Good Lord///LOOK at how dramatic these flares are!!! Would be awesome for that Zoom Lens Flare Shot in a spaghetti western…but wait..this is a prime lens, and it flares like a ba&+$R@! The 23-flare performance on the Canon 50D…OMG…staggeringly AWFUL when shooting toward the light.
 
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