Name: Sigma 20mm f/1.8 EX Aspherical DG DF RF AutoFocus Super Wide Angle Lens with Hood for Pentax AF Cameras - USA Warranty
Brand: Sigma
SKU: SG2018PXAF
Price: 629.00 USD
Availability: Discontinued
Rating: 3.96 (25 reviews)

Sigma 20mm f/1.8 EX Aspherical DG DF RF AutoFocus Super Wide Angle Lens with Hood for Pentax AF Cameras - USA Warranty

Sigma 20mm F/1.8

Sigma

Sigma 20mm f/1.8 EX DG ASP RF Lens for Pentax DSLRs

Adorama

Photography

Lenses

SLR Lenses

Sigma SLR Lenses

Sigma 20mm F/1.8 

Buy: Sigma 20mm f/1.8 EX Aspherical DG DF RF AutoFocus Super Wide Angle Lens with Hood for Pentax AF Cameras - USA Warranty Compatibility: Pentax K-1, Pentax K-1 Mark II

Specifically wanted a large F stop lens for night photography of stars on our up coming trip out west. This lens filled the bill. Reasonably priced and it does Macro very well. Goes well with my two other Sigma telephoto lenses.

Very nice lens.

The lens is surprisingly sharp (especially in the center). But due to the severe coma I found it useless for night photography involving pinpoints of light (e.g. stars, distant lights). I would suggest that its best usage to be portraits and interiors.

surprisingly sharp - forget for astro

I shoot on a nikon d800 and I used the nikon 20mm 2.8 for over a year in nightclubs and music festivals.  

I bought the sigma for the sole reason of having a larger aperture, however, the image quality on the sigma is FAR better than the nikon.

Build quality is a little plasticy but that's too be expected these days, it's not "too" plasticy by any means. Focus ring is smooth and buttery, bokeh, amazing, image quality, sharp. All around great and better than the nikon!

Autofocus is "normally" fast, nothing amazing or slow about it. Highly reccomend this over the nikon.

better than the nikon

This lens is sharp and clean. I think it was an E on the Adorama rating list but I would give it a higher marking. Very clean and well kept.

solid used product

I love this lens, and it works perfectly well with my Nikon D7000 and never did I ever encounter any issues with it. I use primes, and it was with this lens that got me started in building my f/1.8 lens line-up. Starting with this 20mm, followed by the 28 sigmas. Then the Nikkors 35, 85, and a manual focus Nikkor 105mm, all in f/1.8!!!

It's glued on my Nikon D7000!!!

Very Sharp lens at the optimal apetures f/8-f/16 very good at f/7 f/5.6, good at f/4...a bit soft at f/1.8-f/2.8 and f/22, better at f/3/5-f/4.   It's a heavy big lens solidly built but does the job.  Works using infrared with no to min. hot spot when shooting towards the light source. Good close up feature with manual override switch and large focus ring.

Sigma 20mm f/1.8 EX Aspherical DG DF RF

I really can't think of anything good to say about this lens. After much research I decided to buy this lens. I saw a few reviews that said it was blurry, but there were considerably more good reviews. I tried the lens in a very well lit situation and it appeared to be crisp and clean on my LCD. When I downloaded the images to my computer and looked at the print size of the images they were all soft and blurry. Details like lips and eyes were undefined.  
The other thing I noticed was the lens had issues in auto focus, it wouldn't pick-up certain focal points and would keep searching for focal points. I should mention I am a professional photographer that has worked with a few good lenses and if you are a professional this lens will not be good enough. Stick with Canon their lenses were designed for their focusing system. I agree they are way over-priced, but I suppose that its worth it in the long run!

Does not produce crisp photos

This lens is only semi sharp at f/8, so if you need some lens sharper in lowlight this is not the choice. Otherwise, right side is almost always blurry. I send the lens to Sigma to calibrate and it returns the same.

Sorry, not a good lens

This lens won't even allow my D7000 to power up. It seems to work on some older bodies, but I'm sending it back, since it's useless to me.

Not for my D7000

This lens supposedly has great optics. Unfortunately, I never got to use it because it does not work on the Nikon D7000. Google it, and you'll see for yourself. When you attach the lens, the metering cuts in and out, and the AF will not work. I quaduple-checked all my settings, on both lens and camera, and no dice. Apparently, it's a Sigma firmware issue - you have to send the lens to Sigma in Japan for a firmware upgrade, and it takes weeks. [...] Really disappointing, as nobody else makes wide, fast lens for an affordable price.

Will not work with D7000

I use it as my normal lens on the Sigma SD15 because the f1.8 max aperture provides a bright viewfinder. Focus is a bit twitchy because the distance scale is only about 3/4" long

Nice wide normal lens for APS cameras

This lens is one of "the thousand eyes" which the night has. (Thank you Bobby Vee or Vinton or whomever).  It captures the emotion we all feel while experiencing cityscape or the "Starry, Starry Sky". (Thank you Elton John?) Need I say, broadens one's horisons?

Top Shelf ,as expected.

This is another Sigma fast wide angle prime.  I also own the 30mm and 50mm f1.4 and this has a very pleasing bokeh as well as just the right sharpness for portraits.  I think the sharpness at 1.8, while not the razor sharp you'd want for a macro, is just the right sharpness for people.  It is large and heavy and requires an 82mm filter but I don't consider those shortfalls, just artifacts of the design.

A nice feature is that it focuses down to 6.5" which is great for getting those in your face non-flattering shots :)

It doesn't have HSM but it focuses nice and fast on my D90.  

I have never experienced focus problems with any of my six sigma lenses and would not hesitate to buy Sigma again.

Another Sigma wide angle winner

I'm very pleased with this prime lens after the first two months. It's been terrific for shooting in low-light without a flash, and even hand-held shots under those conditions come out nice and sharp. I am also very pleased with the boka. The only potential downside -- you can forget about using your built-in flash with this lens, because it's so broad you get that ugly arc shadow in your frame. But like I said, the great thing is you can shoot natural light even in very dim conditions. I also got some lovely video with this lens on my Canon EOS 7D.

This lens is sharp and fast

This lens is much maligned on listservs because of supposedly poor performance wide open.  At 1.8, however, it is the only 20mm lens of this speed available. While it is a bit soft wide open, it is fine for my purposes. However, stopped down only to f2 or f2.2 my sample becomes extremely sharp.  The minimum focus distance is also extremely close, providing near-macro, wide field capability.

Much Better Than Its Reputation!

This lens is sharp and tasty for landscape, portrait with a group of people, blue hour fotographing. I´ve tested it on deers in the dark swedish summernight´s, togheter with a tripod and a good camera just like Sony A900 it works overall well.
The F1.8 is very good to have when the light disapere.

Fast AF and sharp pics with Sigma 20mm

i like this product for economy

I got this because I needed a fast, wide-angle for a series of group pictures and indoor event pictures where I didn't want to have to rely on a flash.  This has not disappointed.  I've been able to use this for gymnastics action shots in a gymn that has lousy light, too.  The size is a bit of an issue -- I don't have a pocket big enough for it on a summertime shirt and the filter is a monster -- but it's a small deficit when considering all the positives.

Excellent Wide Angle

This is a great lens for the price. Its fast and sharp when you open it up a bit and its not terrible 1.8 either. For the money i would say its a great buy. The only problem is its 82mm filter size is huge so you have to spend a million dollars to get any kind of filters for it.

Good lens

When I got my Pentax K-10-D, once again my next objective was to buy a bright wide angle lens (Zooms Can't Cut It In Low Light). When I step into a Big Old Granite Building I come out with better shots than if I had put a flash on my camera and settled for the coverage it got.  
  This lens is great on my D.S.L.R. and even better on my 35mm.S.L.R. and it takes the same Sigma polarizing filter as the 100mm to 300mm Lens and 24mm to 70mm Lens I planed on buying after it.

Bright Primes Rule

BARGAIN PRICE FOR A HIGH QUALITY FAST LENS. MANUAL ADJUSTMENT GETS THE MOST OUT OF IT.

ULTRA WIDE ULTRA WISE

I love this lens for taking interior shots when I wanted to get as much of a room as I wanted without using flash.  It is sharp and gives excellent results.

Sigma 20 mm f1.8 wide angle

Very fast lens and great depth of field for wide angle photography purposes. With a digital 1.5x factor, it makes for a great photojournalism lens.

Great for indoor architecture shoots!

Fast!! Clear Pictures. Great for indoors like museums or places where flash is prohibited. I use this more than any other lens I have.

Great Lens

Indoor shots without flash is now a reality with this lens, especially with digital cameras, where you can tweak the white balance.  On a digital, you have a respectable 30mm equivalent wide lens at F/1.8.  On a film camera you have a breathtaking 20mm.  It will also focus to a 1:4 macro ratio, giving you an amazing perspective (and depth of field) that you can't get with a normal lens.  The only drawback I have found is that the lens is not small (the size of many zooms, but it doesn't "stretch-out" like most zooms obnoxiously do) and the filter size is an expensive 82mm.  But you don't get F/1.8 without that kind of size.  Don't try the lens.  You'll never go back to the dark world of slow zooms again. . .

Sigma 20mm f/1.8 EX Aspherical DG DF RF AutoFocus Super Wide Angle Lens with Hood for Pentax AF Cameras - USA Warranty

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