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

Reviews Views Date of last review
7 11,594 Mon October 7, 2019
Recommended By Average Price Average User Rating
100% of reviewers $239.83 9.29
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)
$219 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 1-7 of 7

Registered: May, 2014
Location: Linz
Posts: 819
Lens Review Date: October 7, 2019 I can recommend this lens: Yes | Price: None indicated | Rating: 8 

Pros: build and image quality
Cons: minimum focus distance; lens cap; can't mount frontfilters
Sharpness: 8    Aberrations: 8    Bokeh: 5    Handling: 9    Value: 9    Camera Used: K-3   

It's a sturdy and well built lens, with the exception of the somewhat flimsy lens cap (not that it is likely to break but it doesn't hold that good on the lens).

Because of the removeable lens hood and it's near FF coverage the lens can be used with slight restrictions on FF, too.

My infinity focus wasn't quite correct in the beginning but this can be resolved by oneself, although it was a little tricky because of the wide angle of view.

The big and bulky front lens has the disadvantage of attracting some dust (has to be removed if you don't want to spend an eternity in post) and not allowing frontfilters.

My last and maybe biggest concern is the somewhat long minimum focus distance of 0.3m for a fisheye, it's mangeable but a little bit closer would be nice sometimes.

Beside those points this lens is fun to use. While it is a fisheye it has a more even distoriton than other lenses of this type have which I actually like.

While this lens has an A-setting and therefore supports other shooting modes I normaly use the M mode anyhow, because of the wide angel of view you get so much different lightsources and diverse lighted areas in the frame that the automatic programms are unrelyable in my opinion.

For best sharpness I usually set aperture at f5.6 or f8, focus at infinity and shoot away.

I use it mostly for landscape and architectural photography.

With slight defishing in post you can even use it to photograph interiors (as long as you carefully place straight lines in the frame)

Last but not least some expamles:



For landscapes I usually place the horizon in the middle and crop away some sky afterwards:

Vaude Schmugglersteig

A slightly defished example:

Double Spiral Staircase
New Member

Registered: July, 2019
Posts: 1
Lens Review Date: July 24, 2019 I can recommend this lens: Yes | Price: $199.00 | Rating: 10 

Pros: Well built, suitable for aps-c and maybe full-frame
Cons: The front hood cover requires care
Sharpness: 10    Aberrations: 9    Handling: 10    Value: 10    Camera Used: K-5 ll   

Overall, this lens deserves a 10. It's well made, a lot of fun on my K-5 ll, and could be usable in the future on a full-frame camera (minus the removeable hood). As another reviewer wrote, just set the aperture for 5.6 or smaller, and shoot away. One tiny issue was the rear lens cap -- it didn't cover the electrical contacts of the lens, as another reviewer wrote. I went to ebay and found some rear lens caps for Pentax Auto-focus lenses, 2 for 99 cents. Best deal in town. Just be sure the lister of the auction for rear lens caps specifies for "Auto-Focus" or "AF". Otherwise the rear cap will be too small. These caps lock on securely. And the front hood cover arrangement is not perfect, so just be careful with it. My copy is the Rokinon CS ll. I bought it from an authorized dealer on ebay with a one year warrantee. Be sure to get the "CS ll" version. Some sellers really don't know what they've got, and it may or may not be in the title of the listing. The price of both items have gone up since my purchase, the lens went to $239, and the caps skyrocketed to $1.39. This lens is a thrill every time I use it. You won't be sorry.
Site Supporter

Registered: February, 2014
Location: Pennsylvania
Posts: 297
Lens Review Date: July 9, 2019 I can recommend this lens: Yes | Price: $170.00 | Rating: 9 

Pros: Even distortion, little vignetting, sharpness
Cons: Lens cap design.
Sharpness: 9    Aberrations: 8    Bokeh: 7    Handling: 9    Value: 9    Camera Used: Pentax K-3   

My copy is the Rokinon CSII version which I purchased used on the Forum Marketplace.
The lens provides a very useful, reasonably priced entry into the world of rectilinear fisheye lenses on an APS-C camera body. If you carefully compose and keep the lens parallel to the ground, fisheye effects are kept to a minimum making the lens useful for Scenic an architectural subjects. Tilting the lens upward provides pleasing fisheye distortion.

The minimum focusing distance is adequately close for creative uses. Vignetting is quite well controlled after f8 or so. Chromatic aberrations show on high contrast subjects, though usually not objectionably so. All in all a solid performer for a value priced optic.

My major issue with this lens- it is hard to focus accurately. Even using Live View with focus peaking accurate focus is somewhat hit or miss. Stopping down to f11-16 and bracketing focus are recommended for the best results when maximum depth of focus is desired. That said, this lens bumped my Sigma 10-20mm F4.5-5.6 from my daily use bag. It is a fun and useful lens. See photos in the Fisheye Lens thread.
Site Supporter

Registered: September, 2013
Location: Saskatoon
Posts: 2,319
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: 1,775
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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