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Irix 21mm F1.4 Dragonfly Review RSS Feed

Irix 21mm F1.4 Dragonfly

Sharpness 
 4.0
Aberrations 
 1.0
Bokeh 
 8.0
Handling 
 3.0
Focusing 
 5.0
Value 
 3.0
Reviews Views Date of last review
1 5,755 Thu November 24, 2022
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Recommended By Average Price Average User Rating
No recommendations $640.00 4.00
Irix 21mm F1.4 Dragonfly

Irix 21mm F1.4 Dragonfly
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Irix 21mm F1.4 Dragonfly
supersize
Irix 21mm F1.4 Dragonfly
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Description:

The Irix 21mm F1.4 is a manual focus ultra-wide-angle lens designed for full frame.

The lens feature a Pentax KA mount (automatic aperture control) with no aperture ring and it is weather sealed. Focusing is internal and there is a focus lock feature. The lens has 15 optical elements. Of these 4 are ultra-low dispersion glass elements, 4 are high refractive, and 2 are aspherical. The  lens has no threads for a filter.


Irix 21mm F1.4 Dragonfly
© www.pentaxforums.com, sharable with attribution
Image Format
Full-frame / 35mm film
Lens Mount
Pentax K
Aperture Ring
No
Diaphragm
Automatic, 11 blades (rounded)
Optics
15 elements, 11 groups
Mount Variant
KA
Check camera compatibility
Max. Aperture
F1.4
Min. Aperture
F16
Focusing
Manual
Min. Focus
30 cm
Max. Magnification
Filter Size
Internal Focus
Yes
Field of View (Diag. / Horiz.)

APS-C: 66.9 ° / 57.7 °
Full frame: 89.7 ° / 79.1 °
Hood
Included
Case
Lens Cap
Included
Coating
Multi-coated,Nano Coated
Weather Sealing
Yes
Other Features
Focus Clamp,Distance Scale
Diam x Length
95 x 103 mm (3.7 x 4.1 in.)
Weight
816 g (28.8 oz.)
Production Years
2022 to present (in production)
Engraved Name
21 Irix f/1.4
Reviews
User reviews
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Author:
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New Member

Registered: November, 2022
Location: Ceske Budejovice
Posts: 24
Review Date: November 24, 2022 Not Recommended | Price: $640.00 | Rating: 4 

 
Pros: Sealing, build quality except front lens cap.
Cons: Front lens cap continually falling from lens.
Sharpness: 4    Aberrations: 1    Bokeh: 8    Handling: 3    Focusing: 5    Camera Used: Pentax K1    Value: 3   

General impression:
with K1 it has good handling balance, but in general its big and heavy lens.
Lens comes with very practical bag, bag is a bit solid it will make a good protection for lens.
Build quality very good, lens is robust, except front lens cap.
I have no idea how front cap could be so bad, its just don't holds on lens and in general it looks like it is from much cheaper lens. Other people also have problem with it, for now as I know it affects all lens copies.

I have to say, I was expecting a lot from this lens, its advertised as very good astro lens. In my opinion I got a bad copy, therefore I returned it, lens serial number is 09822070019. Never the less I will give it 2nd chance and will order new copy of lens and then will update the post. Cause I think I was simply unlucky.
Maybe with next copy of lens I will be able to recommend it but for now no.

Sharpness: 4 - my copy has an issue. I think good copy could be extremely sharp.
Aberrations: 3 - my copy was really bad.
Boken: nice, smooth.
Handling: 3 - Handling would be 8 if not that front cap. 10 not possible because of weight and size.
Focusing: 5 - very good for manual lens for day time, for astro it's a bit hard, maybe because of bad copy of lens. If not decentering issue would give 8.
Value: 3 - bad copy. In general I was thinking if I should post a review at all. But i think it important to let others now in advance that they could expect some issues.
I think good copy of this lens has protentional for overall 7+ rating. (I'm a bit tuff on quality...)

I made a test for aberrations, took 5 sec shots from f1.4 up to f2.8. Then normalized brightness for all shots in PP and used ASTAP to generate crops with corners to look close on aberrations. Coma and astigmatism are at all F-stops! I think its also has decentering issue, that why in some areas of images star are very sharp and in other not like they were out of focus. Also this lens suffers from chromatic aberration. Details in link below:
https://flic.kr/s/aHBqjAgBWr

Example of photos I was able to get from this lens:
https://flic.kr/s/aHBqjAgzHL

For that I used my Pentax K1, Astrotracer, Sequator for stacking and PP for editing, more details directly in name of photos.
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