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Sigma 10-20mm F3.5 EX DC HSM

Reviews Views Date of last review
28 105,407 Sun February 3, 2019
Recommended By Average Price Average User Rating
89% of reviewers $540.40 8.52
Sigma 10-20mm F3.5 EX DC HSM


This is a super-wide angle lens with a relatively bright F3.5 maximum aperture throughout its zoom range. The lens is in particular suitable for indoor shooting and landscapes. The image format is APS-C and it has a wide angle diagonal viewing range of 102.4-63.8°. The lens has a built-in HSM autofocus motor and offers no provision for screw-drive autofocus.

The lens incorporates an inner focusing system and is constructed with two ELD (Extraordinary Low Dispersion) glass elements and an SLD (Special Low Dispersion) glass element. Further more it has four aspherical lens elements to help correct for distortions.

The minimum focusing distance is 9.4" (24cm) throughout the entire zoom range, which yields a maximum magnification ratio of 1:6.6.

Judging from the field of view specified by Sigma this lens is closer to being a 12-23mm lens than being a true 10-20mm lens.

This lens was preceded by the slower Sigma 10-20mm F4-5.6 EX DC reviewed here.

Sigma 10-20mm F3.5 EX DC HSM
©, sharable with attribution
Image Format
Lens Mount
Pentax K
Aperture Ring
Automatic, 7 blades
13 elements, 10 groups
Mount Variant
Check camera compatibility
Max. Aperture
Min. Aperture
AF (in-lens motor)
Min. Focus
24 cm
Max. Magnification
Filter Size
82 mm
Internal Focus
Field of View (Diag. / Horiz.)

APS-C: 102-64 ° / 92-55 °
Lens Cap
Weather Sealing
Other Features
AF/MF Switch
Diam x Length
8.6x8.9 mm (3.4x3.5 in.)
520 g (18.3 oz.)
Production Years
(in production)
$399 USD current price
$649 USD at launch
User reviews
In-depth review

Buy Lens: Buy the Sigma 10-20mm F3.5 EX DC HSM
In-Depth Review: Read our Sigma 10-20mm F3.5 EX DC HSM in-depth review!
Price: $399
Mount Type: Pentax KAF3 (in-lens AF only)
Price History:

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Sort Reviews by: Date | Author | Rating | Recommendation | Likes (Descending) Showing Reviews 1-15 of 28
Seeker of Knowledge

Registered: August, 2016
Location: Topeka, Kansas
Posts: 12,438
Lens Review Date: February 3, 2019 I can recommend this lens: Yes | Price: $200.00 | Rating: 9 

Pros: seems well made, sharp
Cons: none at this time
Sharpness: 10    Aberrations: 9    Bokeh: 5    Autofocus: 10    Handling: 9    Value: 10    New or Used: Used    Camera Used: K 3   

yes it is heavy but so are some of my other lenses

no problem for me to hand hold

haven't had much time to use it yet, but I like it

no chance to examine bokeh yet

purchased via forum's market place

it is my widest lens
New Member

Registered: January, 2017
Posts: 3
Lens Review Date: December 9, 2018 I can recommend this lens: Yes | Price: $220.00 | Rating: 9 

Pros: Sharpness, autofocus
Cons: Heavy
Sharpness: 10    Aberrations: 8    Bokeh: 8    Autofocus: 10    Handling: 9    Value: 10    New or Used: Used    Camera Used: K-S2   

Purchased used, I find this lens an excellent value. Handles very well, with crisp autofocus and clarity (especially in the center). There is some slight distortion at the corners when shooting wide, but it's not a big issue. I found that learning to compose my shots with it took some time. I am typically shooting at 15-18mm and there is not much I can't address regarding the edges in post; when below 15mm it's better stopped down. The lens is constructed very well and is heavier but have gotten used to it (also have a 17-50mm f2.8 so its comparable in that regard). Overall as a super-wide that is not a fisheye, I really recommend this lens. It has provided me with some excellent landscape shots and I trust it to nail the focus and with sharpness.

Registered: December, 2013
Posts: 486
Lens Review Date: July 23, 2018 I can recommend this lens: Yes | Price: $500.00 | Rating: 8 

Pros: Wide, silent focus
Cons: Bulky, distorsion
Sharpness: 9    Aberrations: 8    Bokeh: 8    Autofocus: 8    Handling: 7    Value: 9    New or Used: New    Camera Used: KP, K-30   

This lens is a well rounded ultrawide zoom. The lens is sharp and has a decent IQ. The barell distorsion at the wide and is a little annoying, a rectilinear ultra wide angle lens should be well corrected. The build quality is good. I should note that, the Sigma lenses has a reversed zoom and focus ring, I don't really mind, but some has to get familiar to the unusual directions.
The constant wide aperture makes the lens able to shoot events too. I'am not a great fun of ultrawide, but it's a useful lens in my kit occasionally.

Here are some images:
IMG160120_0048 by Benjámin Czétényi, on Flickr

IMG160120_0005 by Benjámin Czétényi, on Flickr

IMG160129_0154 by Benjámin Czétényi, on Flickr

IMG160129_0119 by Benjámin Czétényi, on Flickr

IMG161031_0008 by Benjámin Czétényi, on Flickr

IMG161031_0002 by Benjámin Czétényi, on Flickr

IMG160820_0011 by Benjámin Czétényi, on Flickr

IMG160619_0014 by Benjámin Czétényi, on Flickr
New Member

Registered: March, 2016
Posts: 5
Lens Review Date: February 16, 2018 I can recommend this lens: Yes | Price: $380.00 | Rating: 9 

Pros: Construction, well controled distorsion
Cons: Extreme angles sharpnes, cromatic aberrations
Sharpness: 9    Aberrations: 9    Bokeh: 8    Autofocus: 8    Handling: 9    Value: 9    New or Used: New    Camera Used: K3II   

After about 100 photos shot with this lens I can say:

-AF worked very bad, inaccurate, slow, sometimes it did not respond ... After cleaning the contacts seemed to be the same but magically began to respond perfectly, being slower than most of my screw lenses.

-The sharpnes is very good in the center even at 3.5 but the extreme angles are never very sharp, neither at f16 nor at f22 where definition is lost in the whole image.

-The management and construction are very good, not as good as those of the ART range but very good.

-The distortion is very well controlled, I think I like much more in the 17-20 range than the Tamron 17-50 2.8.

-CHROMATIC ABERRATIONS are remarkable and are reduced by closing the diaphragm but they never disappear, although this is common in glasses that are so narrow

Once I read that EX was excellent or excellent and Sigma stayed far away with this goal, I would have called it OK

EDIT: It seems that the K3II and the 10-20 dialogue each time better, the HSM is rare. It is the second lens that I tested on HSM and the previous lens (Sigma 50-150) I returned it because the focus was a horror, but I like this lens more and more
Veteran Member

Registered: August, 2014
Location: Italia
Posts: 347
Lens Review Date: May 4, 2017 I can recommend this lens: Yes | Price: $540.00 | Rating: 10 

Pros: Solid build, sharpness, AF,low distortion,contrast, costant aperture
Cons: none for this price target.
Sharpness: 9    Aberrations: 9    Bokeh: 8    Autofocus: 10    Handling: 10    Value: 10    New or Used: New   

Very honest lens. It delivers a lot for the price.
Feels solid and the AF on my copy is excellent without the need of any adjustment. AF is also extremely accurate. MF is possible in any moment but the MF ring hasn't infinity stop.
Distortion is low;my copy doesn't suffer of CA. There's some vignetting at 10 mm to 14 mm at wide apertures. This lens is sharp.
10 mm of FL are for people who know to use them . Otherwise the 15 limited + 21 limited are a better choice (for double the price) . It takes 82 mm filters but if you're used to square filters, Lee or Nisi holders could be used. A side note: the 24 mm FL is useful so people comparing this lens to Da 12-24 have to consider if it's better the 10 to 12 end towards 20 to 24 zoom end. I don't own Da 12-24 but sigma strenghs are low Ca, low distortion and AF (silent and accurate).
I never used it on a 24 mpx sensor but I suppose this lens would perform fine.EDIT: on 24 mm it seems someway softer.
I really don't understand the critics about bokeh.... guys this is a 10 mm lens....this means all is in focus...but if you want some bokeh, the close focus distance means you can apply some out of focus to the background, but the bokeh is nervous, for my taste.
To sum up:I'm satisfied by this lens and I hve no regrets.
Loyal Site Supporter

Registered: October, 2015
Location: Orange County CA
Posts: 48
Lens Review Date: January 10, 2017 I can recommend this lens: Yes | Price: $450.00 | Rating: 9 

Pros: Very sharp
Cons: Still exploring
Sharpness: 10    Aberrations: 8    Bokeh: 5    Autofocus: 9    Handling: 9    Value: 10    New or Used: New    Camera Used: K-30   

I just purchased this lens (12/29/16) but so far I really enjoy using it. I have found it to be very sharp. I don't expect much bokeh on this type of lens which is fine.
It focuses very quietly and fast on my older K-30. I took both low light (sunset/blue hour), full daylight and interior shots and found it worked very well in all three situations.

I didn't detect much drop-off in sharpness when wide open in the situations in which I used it.

I expect to have a lot of fun with this lens :-)

New Member

Registered: July, 2009
Location: Varese, Italy
Posts: 11
Lens Review Date: January 7, 2017 I can recommend this lens: No | Price: $370.00 | Rating: 5 

Pros: well built
Cons: not sharp, 82 mm filters are expensive
Sharpness: 5    Aberrations: 4    Bokeh: 5    Autofocus: 8    Handling: 9    Value: 5    New or Used: New    Camera Used: Pentax K-7   

After reading many good reviews I decided to buy this but even from the first test shots all the pictures looked already rather soft on the camera's LCD. I tried different focal lengths and apertures, from wide open to fully stopped down, but the results were all more or less disappointing.
I tested it against my 18-55 Pentax kit lens. With the same focal length, aperture, speed, and guess what? The unassuming 18-55 was consistently sharper. I know that Pentax has the best kit lenses but this is ridiculous, I was expecting more from this Sigma.
I really wanted to like the 10-20, but I eventually had to return it. I could have asked to replace it with another copy but there was no guarantee that a second lens would have been better so I think I will keep saving money and buy the Pentax 16-50 or the 15 mm limited.
The only good thing that I can about this lens is that it feels really solid and well built. Unfortunatley the image quality was not what I was hoping for.
New Member

Registered: March, 2015
Location: Paris
Posts: 2
Lens Review Date: March 22, 2015 I can recommend this lens: Yes | Price: $700.00 | Rating: 9 

Pros: Image quality, Very low-distortion,
Cons: you can't use inside flash
Sharpness: 10    Aberrations: 8    Bokeh: 9    Autofocus: 10    Handling: 9    Value: 9    New or Used: New    Camera Used: K20D   

The better wide angle i use
no distortion in corners
Senior Member

Registered: December, 2013
Posts: 109

6 users found this helpful
Lens Review Date: August 24, 2014 I can recommend this lens: Yes | Price: $350.00 | Rating: 9 

Pros: Sharp, 77mm, small
Cons: no constant aperture, distortion at times (minor)
Sharpness: 9    Aberrations: 8    Bokeh: 8    Autofocus: 8    Handling: 9    Value: 9    New or Used: New    Camera Used: K-3   

Just look at how sharp the pictures are.

New Member

Registered: December, 2012
Location: Burnt Store Marina, Punta Gorda, Fl
Posts: 16

5 users found this helpful
Lens Review Date: January 27, 2014 I can recommend this lens: Yes | Price: $599.00 | Rating: 9 

Pros: Build Quality, funtionality, color quality, reliability
Cons: Price, soft edges on some settings.
Sharpness: 9    Aberrations: 7    Bokeh: 8    Autofocus: 10    Handling: 9    Value: 8    New or Used: New   

This lens has many fans and some detractors. Have had the lens now for almost 2 years. Have not used it as much as planned but when I do I find it produces as good as I had hoped. Excellent depth-of-field which is far more important then bokeh on a super wide angle lens. That is something that I don't look for with this lens. When I use it for landscapes I want focus from front to back. This lens delivers excellent depth of field. It is a bit soft at some settings (corners) but in general is as sharp as I need. I think that some reviewers are influenced by other reviewers and a site like Photozone. If we all followed Photozone none of us would have the Pentax 18-135mm which is what is on my K5 most of the time and does a yeoman job for me. I have had more then my share of SLRs and DSLRs and more lenses then I care to own up to. I have never had another lens that has the build quality and workmanship that this lens has. It is truly built like a tank. I feel that if it is built that good it most have had some effort made to produce a top performing lens. The constant f3.5 is a plus. The sweet spot on the lens is around F8. Some say that the same lens, less money and not as fast, is just as good for landscapes. I don't agree. This lens has better glass and specs. Check them out. I find this lens does a good job with HDR and when using a 10 stop ND filter. Both of which I use for landscapes. I do have a polarizer filter. At 82mm it does not do a good job with the sky but does help with water scenes and foiiage. I mostly do birds and other wildlife. I have the Pentax 60-250mm Zoom which in my opinion is Pro Quality. The Sigma 10-20mm f3.5 is not up to that standard but fills the bill for me on the wide angle end.
Forum Member

Registered: February, 2012
Location: Seattle, WA
Posts: 63

3 users found this helpful
Lens Review Date: September 25, 2013 I can recommend this lens: Yes | Price: $649.00 | Rating: 10 

Pros: Image quality, focal range, low-distortion, silent, fast & accurate focusing
Sharpness: 8    Aberrations: 9    Bokeh: 9    Autofocus: 10    Handling: 10    Value: 10    New or Used: New   

In short: an excellent lens and worth every penny of the full retail cost. This review has some info on why I like this lens over the older version (Sigma f/4-5.6) and the Pentax 10-17mm fisheye. And why I need it in addition to the 15mm Limited.

First, I love the 15mm Limited and will probably never sell it, even though this Sigma covers more focal range and is very closely matched in image quality. The work I do often requires one hand free, meaning I need to be able to support my K-5 with one hand while shooting. So I want and need the lightweight Pentax primes like the 15mm.

But I'm SO glad I have the Sigma 10-20! Everyone needs a super wide lens - it's so much fun. and Yes, the extra 5mm in both directions makes a difference! If I could have only one, it would be a tough call, not sure. Times would have to be really tough for me to sell off one of either of these lenses.

I have as many equally fantastic photos from both lenses. the 15mm Limited is more versatile because of size and weight, and a little bit more sharp. However I will never give up the range of the 10-20mm, especially the wide end.

If you're in to photography enough to be reading these reviews, then you need to have a super wide zoom, and this is certainly one of the best options for pentax users. Just look at the photos here taken with this lens, it's such a fun perspective to play around with.

Regarding other super wides:
Unlike the Pentax 10-17, this Sigma isn't a circular fisheye, meaning it doesn't distort the horizon as much. You can shoot all day with this lens, unlike a circular fisheye which, in my opinion, gets kind of gimmicky after a while. The rectangular wide angle of the Sigma never gets old. In fact, people can't get enough of it. One doesn't realize the possibilities and endless joy until one has shot with it.

Reasons to get this lens over the older (and cheaper Sigma f/4-5.6)
-you may, at some point, want to shoot video with your SLR, or you shoot video now. The constant aperture is crucial for video.
-you shoot at dusk, night, indoors, or other low-light situations like winters in the pacific northwest
-you shoot fast moving subjects
The extra f-stop is great to have in any of these situations.

Image sharpness is a little soft around the edges at the 20mm end. Most of your shots will be in the wide end, which is where it excels. The narrow end is there if you need it and most people won't notice the softness around the edges. Center sharpness is excellent throughout the zoom range so it's not really an issue for me.

Build quality on this lens is exceptional. Focus is spot on, it's consistent, and so quiet I can barely hear it. The feel of this lens in your hands is really nice.

Like this lens so much I hope it lasts forever, and looks like it will.

Registered: February, 2011
Location: Maine
Posts: 2,949

7 users found this helpful
Lens Review Date: July 20, 2013 I can recommend this lens: Yes | Price: $600.00 | Rating: 9 

Pros: Wide; Quiet; Versatile
Cons: Learning curve involved; Watch out you don't shoot your shoes...; A bit more expensive than some of its competition
Sharpness: 9    Aberrations: 8    Bokeh: 9    Autofocus: 10    Handling: 9    Value: 8    New or Used: New   

I'm feeling a bit out of sorts reviewing a lens of this cost - everything else I have is both (much) cheaper and (much) longer. The closest competition to it would be the 18-55mm kit lens, so it kind of stands out in a league of its own for me.

I had the choice of buying the older, cheaper variant of this lens or the constant apertured 3.5. I picked the 3.5 since with my tendency to take night shots, 3.5 @ 20mm is a nice option to have. The other big contributing factor is the odd-numbered blades which give nice, hefty starbursts when I deliberately go for such things.

I find the lens incredibly easy to use - the rings are all in (mostly) handy places, and the AF/MF switch on the lens (kind of redundant on a K-30 body) is handy to have.

The hood is a bit finicky - it can be screwed on off kilter easily enough that you'll sometimes accidentally introduce corner shadowing from it when shooting at the 10mm end of things.

That said, it all boils down to what the quality of the images it kicks out are, and while it can get fuzzy (and CA prone) in the corners, dead center the lens tends to be sharp throughout, and with my style of shooting I don' usually care about the corners anyhow.

Overall the lens is fast, light enough for what it is, and versatile enough to even pull duty portraits or faux-macro work (though its obviously neither).

I spent a solid month using the month for a Single In challenge, and actually started to get bored because the lens wasn't challenging me enough towards the end with whatever bizarre test I wanted to give myself with it.

Care does have to be taken with distortion, but that common to any lens that goes this wide.

While there are cheaper alternatives out there, if you want a good, 'night time' UWA zoom, I don't know if I could of done worse grabbing this one. I'm highly satisfied.

Here are some samples of what I've been able to do with the lens.

Head of Falls; Waterville, Maine by Jody Roberts, on Flickr

SI - May 8, 2013; The Northern Cross; Sunkhaze Meadows; Benton, Maine by Jody Roberts, on Flickr

SI - May 10, 2013; Night Tree; Winslow, Maine by Jody Roberts, on Flickr

SI - May 19, 2013; The Kennebec; Waterville-Winslow, Maine by Jody Roberts, on Flickr

SI - May 2, 2013; He Came From the Other Side of the Couch by Jody Roberts, on Flickr

SI - May 11, 2013; Projecting by Jody Roberts, on Flickr

Just to show gaining bokeh IS possible, though kind of tedious a you need to get right up on the subject to do so.

Library Bokeh; Waterville, Maine by Jody Roberts, on Flickr

SI - May 29; Rain, Rain, Go Away... by Jody Roberts, on Flickr

And if you really decide to play around...

Tree Planet; Waterville, Maine by Jody Roberts, on Flickr
Veteran Member

Registered: June, 2011
Location: Near Sydney, NSW
Posts: 331
Lens Review Date: July 4, 2013 I can recommend this lens: Yes | Price: $350.00 | Rating: 4 

Pros: Well built, sharpness in the centre
Cons: Not as wide as the 8-16, bigger and heavier than it (??), softer (especially at the edges and corners). Just a bit not good enough for the price.
Sharpness: 6    Aberrations: 7    Bokeh: 5    Autofocus: 8    Handling: 2    Value: 4    New or Used: New   

I actually got this at such a low price because of a pricing error that the online store then chose to honour, which is good of them, but boy am I glad I didn't pay the full price for it.
I have the DA* 16-50 and eventually I decided that a better match for it was the 8-16 rather than this. And then the 8-16 turned out to be a whole lot better even though it's slower. I just prefer the 8-16 on basically every level, except for the lack of filters, which isn't really the 8-16's fault.

Anyway, buy this if it's really cheap but not otherwise.
Senior Member

Registered: November, 2012
Location: London
Posts: 157
Lens Review Date: February 14, 2013 I can recommend this lens: No | Price: $700.00 | Rating: 7 

Pros: Center sharpness, focusing, good build
Cons: corners, esp. at 10-12mm
Sharpness: 7    Aberrations: 7    Bokeh: 9    Autofocus: 10    Handling: 9    Value: 4    New or Used: New   

I think this lens is very sharp in the center at all apertures and focal lengths, however the corners are extremely lacking unless stopped down to f7.1 or f8. I would recommend this lens, but the Sigma 8-16 is only $49 more (only Ł10 more in the uk), and is quite a bit wider and has much improved corners, aswell as less distortion. This lens has great bokeh, af, handling, and centers, but it has dreadful corners and severe ca, and I cannot give it any more than a 5 for value for money because the Sigma 8-16, which is sharper everywhere and has less distortion and aberrations. Bargain hunters could find the 8-16 used cheaper than this, in which case go for it. This lens has served me well but I will have to return it for the 8-16 as the corners are a nightmare.

Don't buy.
New Member

Registered: August, 2011
Location: Boston
Posts: 1
Lens Review Date: November 13, 2012 I can recommend this lens: Yes | Price: $745.00 | Rating: 10 

Pros: The BEST superwide zoom, hands down
Cons: OK 82mm isn't as cheap as 77mm but it helps vignetting, so I prefer it
Sharpness: 10    Aberrations: 10    Bokeh: 10    Autofocus: 10    Handling: 10    Value: 10    New or Used: New   

I give the bokeh a 10 because it's not a factor on a lens this wide, and I'd rather give a 10 than anything else, when it comes to this lens.

You can go ahead and asume that I give EVERYTHING about this lens a 10, except the things I address here, which I'm ADDRESSING not criticising:

1. 82mm filters. Everyone mentions it. Yes it isn't great, but it's completely necessary. This lens vignettes way less than the other two 10mm starters, and about the same amount as the Pentax 12-24, which is not as wide so it doesn't count. Then when you add a filter (and especially two filters) the 82mm thing really makes sense.
With TWO slimline (low profile frame) rotating filters, you'll be able to use this at 10mm. That's something the other superwides can't say.
Then with the Lee (or similar series) holder set up, it'll be completely useable at 10mm - and remember the Lee W/A 82mm adapter doesn't cost any more than the 77 or 72 or anything...
If you don't believe me that 82mm filter thread's necessary - look at the Canon 16-35mm f2.8. It wouldn't have an 82 while it's brother, the 17-40mm had a 77, for no reason...

2. Size and weight... Well, they're all big, this one feels the nicest (or the Pentax which is $250 more) and it's normally on a tripod anyway.

3. Cost. It's well worth it over the slower Sigma, which is crap. The Tamron is OK but for landscapes, this just soars ahead after 100 or so landscapes, you'll appreciate the sharpness no matter how much more it cost - and it's still cheaper than the tighter crop Pentax.

Get this one. I've owned them ALL (yeah I know, LBA) and this one is THE one.

This is with an imitation Lee filter holder and 82mm ultrawide adapter, a very solid and easy to use setup with no vignetting.
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