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Samyang 8mm F3.5 UMC Fish-eye CS II

Reviews Views Date of last review
4 8,921 Wed November 22, 2017
Recommended By Average Price Average User Rating
100% of reviewers $267.50 9.50
Samyang 8mm F3.5 UMC Fish-eye CS II

Samyang 8mm F3.5 UMC Fish-eye CS II
Samyang 8mm F3.5 UMC Fish-eye CS II
Samyang 8mm F3.5 UMC Fish-eye CS II


This is the second generation of Samyang's 8mm F3.5 fish-eye lens for the APS-C format. The diagonal field of view is 180 degrees. Per Samyang the lens cam be used on a 24x36mm full frame camera if the lens hood is removed. We would expect some heavy vignetting in this case. The optics feature one aspherical element.

Samyang 8mm F3.5 UMC Fish-eye CS II
©, sharable with attribution
Image Format
Lens Mount
Pentax K
Aperture Ring
Yes (A setting)
10 elements, 7 groups
Mount Variant
Check camera compatibility
Max. Aperture
Min. Aperture
Min. Focus
30 cm
Max. Magnification
Filter Size
Internal Focus
Field of View (Diag. / Horiz.)

APS-C: 180 °
Pouch included
Lens Cap
Weather Sealing
Other Features
Diam x Length
75x77.3 mm (2.95x3.04 in.)
415 g (14.6 oz.)
Production Years
(in production)
$199 USD current price
User reviews
In-depth review

Also sold under the Rokinon brand and possibly other brand names as well

Buy Lens: Buy the Samyang 8mm F3.5 UMC Fish-eye CS II
Mount Type: Pentax KA
Price History:

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Sort Reviews by: Date | Author | Rating | Recommendation | Likes (Descending) Showing Reviews 1-4 of 4
Site Supporter

Registered: September, 2013
Location: Saskatoon
Posts: 1,968
Lens Review Date: November 22, 2017 I can recommend this lens: Yes | Price: $230.00 | Rating: 8 

Pros: Inexpensive, well-built, automated exposure
Cons: Not sharp until f5.6
Sharpness: 8    Aberrations: 8    Bokeh: 5    Handling: 5    Value: 8    Camera Used: K-30   

The lack of AF isn't a problem as far as I'm concerned, I try to use hyperfocal distance to get the portion of the image (much larger than a spot) I want in focus, so I would be focusing manually, regardless. Flare resistance is decent for such a large front element and once you get your head around the curvature of a fish-eye lens, distortion is much less than expected. Minimum focus distance of 12 inches is twice that of the DA 10-17, but with a 180 degree field of view it has never been an issue. This is a stereoscopic fish-eye, as opposed to equisolid like the DA 10-17, so objects on the sides are not as "squished" and seem to look more natural (to me, anyway). There is an excellent explanation of this in the in-depth review of ultra wide lenses here on PentaxForums.

P.S. Mine is the Rokinon Fish Eye CS (not CS II) and the hood is not removable.


Registered: May, 2016
Posts: 1,113
Lens Review Date: June 24, 2017 I can recommend this lens: Yes | Price: $230.00 | Rating: 10 

Pros: build and image quality, Av
Cons: lens caps
Sharpness: 10    Aberrations: 9    Bokeh: 10    Handling: 8    Value: 10    Camera Used: K-3II   

I like the uniformly curved distortion, there's clear detail up to the edge of the frame. Sharpness is quite good, although I don't really know what to expect from a fisheye. At f5.6 there's only a little blue/yellow CA but nothing bad at all (edit: lensfun/darktable have a CA correction profile that works great, just need to enable it and set the projection to stereographic). Contrast and colors are fine, but it's not a HD limited, the colors are less vibrant. Not sure how to rate bokeh, nothing is ever really out of focus due to it's relatively long minimum focus distance... so 10 because the "out of focus" look soft but not busy.

Build quality is very nice, the focus ring is dampened and has a good throw. The aperture ring is useful, but the "A" setting is even better.
Overall only the hood and cap are a little too big, but at least the front element is well protected when they're in use. I took a couple points off handling because the lens hood is makes it difficult to fit in smaller bags, even though the lens itself isn't that large. Also a negative point is the rear cap which doesn't cover electrical contacts. But this is really all I can think of, it's a nice lens for very little money.
New Member

Registered: July, 2011
Posts: 3
Lens Review Date: December 22, 2016 I can recommend this lens: Yes | Price: $360.00 | Rating: 10 

Pros: Very sharp, Balanced fish eye and light
Cons: Cannot mount filters
Sharpness: 10    Aberrations: 8    Bokeh: 8    Handling: 10    Value: 10    Camera Used: K3   

Bought this for the sole purpose to catch the northern lights. Surprised that it performed much better than the 12-24 Pentax UWA lens which I had. Though its manual lens but the K3 works very well with it. No regrets getting it.
New Member

Registered: December, 2016
Location: North Germany
Posts: 1

2 users found this helpful
Lens Review Date: December 8, 2016 I can recommend this lens: Yes | Price: $250.00 | Rating: 10 

Pros: tack sharp, vivid colours, removable lens hood
Cons: none
Sharpness: 10    Aberrations: 10    Handling: 10    Value: 10    Camera Used: K-5   

This second edition is far better than the first one. It has got brilliant IQ.
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