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Sigma EX DG Diagonal Fisheye 15mm F2.8

Reviews Views Date of last review
15 76,640 Mon December 25, 2023
Recommended By Average Price Average User Rating
100% of reviewers $373.21 9.33
Sigma EX DG Diagonal Fisheye 15mm F2.8


This lens produces a180 angle of view diagonally on the 35mm full frame format, a bit less on APS-C.As a diagonal fisheye, this lens produces a notably distorted image that fills the entire frame. Its narrow minimum focusing distance allows for working with unique perspectives with close-up subjects. Additionally, the bright F2.8 maximum aperture benefits working in difficult and low-light conditions by allowing the use of faster shutter speeds.

Sigma 15mm F2.8 EX DG Fisheye
©, sharable with attribution
Image Format
Full-frame / 35mm film
Lens Mount
Pentax K
Aperture Ring
Yes (A setting)
Automatic, 7 blades
7 elements, 6 groups
Mount Variant
Check camera compatibility
Max. Aperture
Min. Aperture
AF (screwdrive)
Min. Focus
15 cm
Max. Magnification
Filter Size
Internal Focus
Field of View (Diag. / Horiz.)

Full frame: 180 °
Lens Cap
Weather Sealing
Other Features
Rear Filter Mount,Fisheye
Diam x Length
73.5x69 mm (2.9x2.7 in.)
370 g (3.05 oz.)
Production Years
to 2021
USD current price
User reviews
Accepts gel filters at the rear

Buy Lens: Buy the Sigma EX DG Diagonal Fisheye 15mm F2.8
Price: $609
Mount Type: Pentax KAF2/KAF (screwdrive AF)
Price History:

Add Review of Sigma EX DG Diagonal Fisheye 15mm F2.8 Buy the Sigma EX DG Diagonal Fisheye 15mm F2.8
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Senior Member

Registered: May, 2013
Posts: 103
Review Date: December 25, 2023 Recommended | Price: $120.00 | Rating: 9 

Pros: Weight and size
Cons: Noticeable vignetting in corners
Handling: 6    Value: 9    Camera Used: K-1    New Or Used: Used    Autofocus: 3   

Mine has strong front-focusing, AF becomes almost spot on at adjustment set to -10. (but somehow K-5 II does well even at 0)
This has wider field of view vertically than Sigma 12-24mm.
Maximum magnification is ~1:3,5 in the center.
Outer parts of sharpness field are slightly curved towards the camera.
Auto-matched profile from Adobe DNG Converter works well (PENTAX (Sigma_15mm_F2.8_EX_DG_DIAGONALFISHEYE ) - RAW.lcp).
The focusing scale is very obviously incorrect including infinity mark. Correct distance is being pointed at by red shift mark (R).
DOF marks look exaggerated, the hyperfocal distance starts somewhere slightly past R pointing at 1m at wide open.
There is almost no way to manually focus precisely between 1m and infinity, the throw is minimal and there is zero friction in the ring.

AF screw has slight wobble which does not affect accuracy unlike my 75-200 F3.8.
AFing from macro to far object causes camera to overshoot past infinity. If camera does only one AF move then you are basically guaranteed to miss, in my case it backfocuses slightly (but noticeably).

Get a Rokinon 12mm if you want correct focusing scale probably (I have not verified it).
Loyal Site Supporter

Registered: March, 2007
Location: Toowoomba, Queensland
Posts: 23,920

2 users found this helpful
Review Date: January 20, 2019 Recommended | Price: $500.00 | Rating: 9 

Pros: Sharp across the frame, small and light, quality build, wide FOV
Cons: Not of the calibre of a Limited lens, some flare
Sharpness: 9    Aberrations: 7    Bokeh: 8    Handling: 9    Value: 8    Camera Used: K-1 Mark II    New Or Used: Used    Autofocus: 9   

This is an underrated lens in the full frame format.
There is (at the time of this review) no modern full frame fish eye lens option available from Pentax currently in production. For the fish eye effect, one has to resort to the legacy F 17-28 or the various A and M varieties of Pentax fish eye lenses suitable for full frame photography while we wait for the upcoming DFA version.

In the meantime, I have this little beauty that has produced some stellar results, something I thought would not be seen having been spoilt by the DA 10-17 on all my previous APS-C cameras. This Sigma 15/2.8 is impressive with its colour contrast, its exquisite sharpness in both short and long distance focusing, reasonably (though not the best) good flare control, and its swift focusing response. Its build quality is good, with strong plastic lined by Sigma's rather ordinary matte finish. But the image quality on the lens more than makes up for any of its shortcomings.

Fish eye photography is fun and rewarding when used well, and for now this lens will fit the bill on a full frame camera.

Close up by Ash

Flare control by Ash
Loyal Site Supportaxian

Registered: September, 2013
Location: Texas
Posts: 503

2 users found this helpful
Review Date: May 8, 2017 Recommended | Price: $460.00 | Rating: 10 

Pros: Very sharp, fast, Fast accurate focus.
Cons: Awkward hood. no quick-shift focus.

It seems I have a good copy or the last reviewer had a lesser copy.. Far sharper and with less CA than the last reviewer's. This lens far exceeded my expectations for sharpness, usability, and focusing.

It utterly blows away my SMCP 17/4, and that's a good copy that has produced many keeper images.

When de-fished, it produces a wider and sharper image than my FA20 at same aperture. Has better color rendering, to boot.

For a fisheye, the (rather limited) amount of bokeh it produces is pleasing.

The accurate autofocus is indispensable for monopod overhead shots when using a remote trigger. Fast, doesn't hunt much, and required zero adjustment.

Although the two-piece hood is a bit clumsy, it is sturdy, and fits securely.

It's pleasantly compact.

In a nutshell this was a surprise winner for me, was worth every penny paid and I wholeheartedly recommend it. It frequently makes it into my pack for shooting events.
Veteran Member

Registered: January, 2009
Location: London
Posts: 573

4 users found this helpful
Review Date: January 6, 2017 Recommended | Price: $450.00 | Rating: 5 

Pros: Compact, great build quality, good lens coatings
Cons: In the extremes of the image, very soft and lots of chromatic abberation
Sharpness: 2    Aberrations: 2    Bokeh: 5    Handling: 10    Value: 6    Camera Used: K1    New Or Used: New    Autofocus: 10   

I bought the Sigma 15mm f2.8 fisheye from what is almost certainly a grey importer; 360 versus 500 from the big names.

A very nice lens, really well made.

I can speak only as a "rectilinear user" since I am not after a fisheye effect at all, and bought this lens because there are almost no modern wide angle lenses for the full-frame K1. There is the Pentax 15-30 which is a very expensive and very heavy (over 1kg) chunk of glass, making the K1+lens over 2kg.

This lens can be de-fished pretty well (I use Lightroom 6.5) so it is a good solution for this requirement. It supports the "A" (aperture controlled by camera) and autofocus modes, which you won't get with any of the old film-era lenses. This shortage of modern lenses is a big drawback of the K1, but it didnd't bother me much since I rarely need wide angle and shoot mostly with the excellent Pentax 24-70 f2.8.

Anyway, here we go:


With the lens profile applied in LR 6.5

The 2nd pic had the highlights reduced a little. But this is just an illustration of what LR does when the lens profile is applied. It turns the fisheye into a rectilinear lens. Interesting! You can see the angle of view is reduced (obviously - you are applying pincushion, so have to crop) and my wild guess is a loss of about 10 degrees. so maybe that makes it a 17mm or so lens... still a good result given there are no modern 17mm lenses for the K1

As regards quality, I have put some files on dropbox but if I post the link, DB will pull my account due to the traffic. So if anyone is interested, drop me an email. The pics won't be copyright and can be rehosted anywhere.

On the above pic, zoomed in 100%, this is the centre (I used centre spot focus)




The left corner, for the three apertures respectively:

So, lots of chromatic abberation (which dosn't get better with reducing the aperture) and generally poor sharpness, but this lens was 360 and e.g. the Pentax 15-30 is over 1000...

The CA is easily removed in LR

As regards flare, here the low winter sun is shining into the front lens element. Not bad at all, for a low cost lens.

This pic shows two roadsigns; one in the middle and one blue one to the right

Here they are 1:1, f5.6 (f2.8 is very similar)

again after the purple CA removed in LR. The two roadsigns should be about the same distance so there is a significant loss of sharpness to one side (on the blue sign).

However much of that loss of sharpness is due to LR's pixel replication in the lens correction. This is the blue sign, 1:1, from the non-lens-corrected image

That is to be expected since the lens correction involves stretching (pixel replication).
Loyal Site Supporter

Registered: October, 2009
Posts: 137

2 users found this helpful
Review Date: September 6, 2015 Recommended | Price: $300.00 | Rating: 10 

Pros: Very sharp, small size, quality, fast AF, close focus, IQ and colors
Cons: none really
Sharpness: 10    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 10    Camera Used: K-3 Silver    New Or Used: Used    Autofocus: 10   

I was lucky to pick one up for a very low price.....after monitoring for an opportunity to do so for quite a while...

I am an ultra-wide 'LBA' guy and have many alternatives that I can compare this Sigma 15 with:
e,g DA 10 17, Samyang 8, 10, 14 and DA 15, Sigma 8-16.....(and I used to have the DA 12 24 and Sigma 10 20)

So How is this one doing then? Well....fantastic! It's a very nice walkaround on a K3 with grip. Bigger than the DA 15...but comparable
very nice for snapshots and close focus, for street, for nature....and a bit more fun than the DA 15 (although I would never sell the DA 15! It has its own good qualities)

here are some examples

New Member

Registered: August, 2014
Posts: 13
Review Date: February 22, 2015 Recommended | Price: $340.00 | Rating: 9 

Pros: Fast, close focus at 15cm,ver sharp between f4 and f8
Cons: bad flare, no filter (protection), autofocus
Sharpness: 9    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 9    Camera Used: K-3    New Or Used: New    Autofocus: 9   

I purchased it about 6 years ago in austria for a bargain of 450 and use it on my K7, K5 and now the K3.
Because of it lightweight and small dimension, its my favourite for making freefall skydive fotos. But I have to be aware, that it produce bad lens flare when making photos against the sun.
Its sharp between f4 and f8, at f2,8 CA is a bit of a problem, but LR eliminates this really well.
Sometimes the autofocus was going mad when i put it on the K7 and start hunting. But it works pretty well on the K5 and K3.

New Member

Registered: July, 2009
Location: manchester, UK
Posts: 11
Review Date: November 22, 2012 Recommended | Price: None indicated | Rating: 9 

Pros: Sharp, well made
Cons: Quality variable! CA.
Sharpness: 8    Aberrations: 5    Bokeh: 6    Handling: 9    Value: 5    New Or Used: New    Autofocus: 8   

OK not had it long so these are my initial thoughts. Purchased in UK and currently EXPENSIVE. Primary reason to buy was an aurora photography trip next year for which I want a fast wide angle prime, sharp to edge of field wide open. From the reviews I've seen this ticks those boxes better than anything else.
The first lens I received was not sharp when autofocussing. I could get sharp images by manually focussing, but it back focussed beyond the amount I could correct using a K5. So I sent it back, and the new example (supplied very promptly by the retailer) seems excellent.
And is sharp right up to the edges of a K5 frame (albeit cropped image on a full frame lens) wide open.
Both examples suffered from purple CA at frame edges if you pixel peep (easily corrected in Lightroom).
And although the image distortion can be both fun and useful, if you DON'T want it and would like a rectilinear image, just use the Lightroom 4 Sigma 15mm lens profile and hey presto, you have a non-distorting lens (at the cost of some edge cropping).
Very cool, best of both worlds.
I'll post some further thoughts when I've used it more.

Update Feb 2013. OK and now I have used it more. Just returned from my aurora trip, the lens works fine for extended periods at -20C. The focus scale on my example is off and when manually focussing, infinity focus is just beyond the 4 feet marker on the focus ring. Minor issue and autofocus is fine. An excellent lens for the somewhat esoteric field of aurora photography. Very well built, nice to handle,and very sharp right to edges of frame.
Senior Member

Registered: June, 2011
Location: Berlin
Posts: 197
Review Date: November 6, 2012 Recommended | Price: $500.00 | Rating: 9 

Pros: sharp, fun, lightweight, FF ready
Cons: No filter (front)
Sharpness: 9    Aberrations: 8    Bokeh: 9    Handling: 9    Value: 9    New Or Used: Used    Autofocus: 9   

This lens is for fun; you can't expect normal view from this lens.

AF function is cool, much better than any Tamron lens that I have (Tamron 28-75, Tamron 90 and Tamron 18-200).

You can't get any normal filter on the front element of this lens. For ND you have to use gelatic type (mounted on the rear element of lens). Because you have no filter to protect the lens , and because the minimum focus distance is too short, you should be very careful when taking picture for children or animals. My dog, for example, always to touch the lens :^^

Lensfun ( hasn't supported this lens yet and you need to build your own calibration data.This is to make ultra-wide picture on digital pictures.

On FF camera (film camera!) the effect is much much more than on digital camera.

Sample pictures

Forum Member

Registered: August, 2012
Location: Greece
Posts: 51

1 user found this helpful
Review Date: August 10, 2012 Recommended | Price: $340.00 | Rating: 10 

Pros: Sharp, Good Glass Quality, great bokeh, fast AF, low distorsion, really close focus, accurate colors, no aberrations, looks great!
Cons: None so far!
Sharpness: 9    Aberrations: 9    Bokeh: 10    Handling: 10    Value: 10    New Or Used: New    Autofocus: 10   

Great lens so far! great coverage with the logical distorsion of a fish eye lens,
its really sharp and it give an outstanding sharpness with high iso levels!
i used it with my K-5 with 3200 and although it had noise it lost almost no detail!
the colors are accurate! giving in a normal environment with auto white balance set a little bit of orange (extremely easy to correct!) most will not even recognize actually thats why i didn't put it as a con, it has a good and accurate AF although i didn't tested it in a low light condition much yet!, it is a light lens and looks great and pro...its not something that must be taken highly but its also an add to this great lens!
I totally recommend this lens! its really cheap for a fish eye lens and it gives you better to equal quality of an expensive 15mm of canon or Nikon (I don't mention the pentax 15mm because i've ony tested canon and nikon 15mm)

Registered: May, 2010
Location: now 1 hour north of PDX
Posts: 3,897
Review Date: June 15, 2012 Recommended | Price: $385.00 | Rating: 10 

Pros: sharp, f/2.8 available, close focus, excellent color/contrast, FF-ready
Cons: umm.. it's not the DA15?
Sharpness: 10    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 10    New Or Used: Used    Autofocus: 10   

This was the hardest lens review to date - partly due to peer pressure. I've never owned a 10 before, so can I really be certain? After testing the lens and probing both mind and heart, I will let the perfect score stand: it's much closer to 10 than 9 in my book, maybe 9.8.

I had hoped to pick up either this or a DA15, as each has merits. This one is heavier but 320g is not heavy, so that's not a reason to demote it. And yes this one distorts, but on aps-c results are just a tad bizarre and I'm OK with that (and software can de-fish the shots that really need it). The Sigma also has great sunpoints and incredibly slight flare, so that appears to be a draw. Note that my copy is the EX not-DG version so flare is at its 'worst' with no DG coatings.

Points in the Sigma's favor are listed in the 'pros' (though most can be found on the DA15) and are all important to me except maybe FF (though I've put it on my film ME and really enjoyed it). Unique features would be f/2.8, 1:4 close focus and FF capable, plus this has an aperture ring and 'A' setting which makes it friendly with film bodies and my micro4/3 camera. The biggest point in favor is price, which was easily $100 less than most used DA15s that I had seen.

I really have enjoyed this lens and whatever happens with my kit this is a keeper!
More shots at my picasa site.

Worst-case distortion with the K-5 on the left

closeup, f/5.6

I believe that's a smidge of flare near the front tire..
New Member

Registered: October, 2009
Location: Rijeka
Posts: 15

1 user found this helpful
Review Date: March 14, 2012 Recommended | Price: $380.00 | Rating: 10 

Pros: Build quality, sharpness, wide angle, contrast...
Cons: Lens flare, CA, lens cap
Sharpness: 10    Aberrations: 9    Bokeh: 9    Handling: 10    Value: 10    New Or Used: Used    Autofocus: 10   

How the lens has to be good when the biggest drawback is a lens cap? Yes, it is a bit funny and there is no point taking off only one part because you will get a black ring in your photos. When I bought it I was interested in fisheye effects but this lens is much more. Fisheye effect on apsc-bodies is hard to see and it can be easy corrected when you don't need it. I have a non-DG version and I think there are not any differences. Lens is very sharp from 2.8mm in whole areas (center and corners), it is wider and sharper that Pentax 15mm F4.

This lens is always in my bag, most of the hiking I use it mostly for landscapes and macro photography.

This lens is still one of my favorite lens but I must keep in mind that it produce a bad lens flare when making photos against sun. Here is an example:

CA is noticeable but it can be corrected in PP. Lens still deserve 10 and it is always in my bag!
New Member

Registered: September, 2006
Location: Calgary, Alberta
Posts: 18
Review Date: February 23, 2010 Recommended | Price: $350.00 | Rating: 10 

Pros: Fast, great size, nice look to shots.
Cons: None

This is one of my favourite lenses. I shoot a lot of local indie rock/punk shows, and this thing is perfect for catching the action in low-light conditions. The 15mm length and slight (but not insane) fisheye effect add a really great feel to the shots. I rarely leave the house without this lens.

Registered: September, 2006
Location: Millstone,NJ
Posts: 6,491

1 user found this helpful
Review Date: July 12, 2009 Recommended | Price: $400.00 | Rating: 10 

Pros: great close focus of 15cm/5.9" and very sharp at F4 +
Cons: you have to be more carefull keeping the glass clean
New Or Used: New   

I use it more than any other lens with my K-7 in movie mode to shoot home videos of the kids because of the larger DOF and wide angle. It's fantastic shooting HD video from 1" in front of this lens and in focus !!!

Here it is on my K-01 :
Senior Member

Registered: February, 2008
Location: Paris
Posts: 222
Review Date: July 15, 2008 Recommended | Price: $425.00 | Rating: 10 

Pros: Sharpness, contrast, built
Cons: Lens cap, flare

I purchased this lens a week ago from a member of this forum and I am very happy with it.

First thing that strikes is the strange lens cap. It comes in two parts, one is a regular clip on cap that mounts onto a strange circular cap that slides onto the built in hood. So no filters can be used on this thing. It is not the easiest system to get on and off, and actually is a little PITA. I am also worried that after a few years, it may not work as well. We will see.

Once the cap is off, this lens is a tone of fun. It is a very well built lens, and the manual focus feels very nice but it is not really needed. The Autofocus works well and this thing has such a huge depth of field that it doesn't really matter anyways. With the crop factor, the Fisheye effect is not too pronounced, and depending on how you compose your shots it may not be visible at all.

It has a very close minimum focusing distance making it a really interesting lens with which you can be very creative.

Finally, the images it produces are very sharp straight from f2.8, and it is a very contrasty lens. Also, I haven't had any problem with CA yet, so I am glad that I purchased this lens over the DA 10-17.

Here is a sample pic at f8.
Veteran Member

Registered: November, 2006
Location: Virginia, USA
Posts: 1,300

1 user found this helpful
Review Date: March 14, 2008 Recommended | Price: $275.00 | Rating: 10 

Pros: Sharp sharp sharp! Great color and contras.
Cons: None realy

Excellent lens from every perspective!

Sharp, even wide open
Great color and contrast
Fast and accurate AF on K10D and K100D
Huge DOF
Excellent metering in both cameras!

Fun lens to use, well worth adding to a bag at the right price!

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