Sigma 20mm f/1.8 f1.8 EX DG RF ASPHERICAL

[perry_cas]

<p>I recently bought a 5d and am thinking about 'what wide'? the sigma 20mm f1.8 looks interesting, but I havent been able to find much in the way of reviews so was wondering if anyone had any experience with it, or any other recommendations in this size or a bit wider from any of the other manufacturers in this price range. I am not much of zoom fan, I do prefer primes having had nothing but a lack of satisfaction from the zoom i have used in the past.<br>

Thanks<br>

Perry</p>

<h1 ><br /></h1>

[alan_bryant1]

<p>the-digital-picture.com has a pretty disappointing review, at least for full-frame use.<br>

http://www.the-digital-picture.com/Reviews/Sigma-20mm-f-1.8-EX-DG-Lens-Review.aspx<br>

There aren't a lot of wide primes available. In zooms, the 17-40L and 16-35L have good reputations. There's a lot of reviews at that site.</p>

[chris_autio]

<p>Hi Perry, I have a 10-20 Sigma. Not sure if I can help you, but this lens has very good edge to edge sharpness. I do my lens correction in Photoshop. It's about $600/Chris</p>

[kasperhettinga]

The sigma 10-20 does not work on a FF body.

If looking for a zoom, sigma makes two lenses working on FF: 12-24 ULTRA-wide and a 15-30.

[rainer_t]

<p>From hearsay ... the 20/1.8 is a quite questionable lens ... borders are never great (not even stopped down), and center becomes sharp behind f/2.8 ... wide open performance very poor. So, you can use the Canon 20/2.8 as well ... and than one is better build and has ring USM.</p>

<p>I have Sigmas 24/1.8 ... which isn't overly good on a crop-1.6, but which I like much better on fullframe (film as well as on the 5D).</p>

[lester_wareham]

<p>The Canon 20/2.8 would probably be a better choice if looking for a fairly wide full frame lens, the two zoom options 17-40/4L or 16-35/2.8L II are also an option. Unless you need to speed the f4 zoom is probably as sharp as the prime or very close to although there is probably more barrel distortion.<br>

Another alternative if you can find one second hand is the discontinued TOKINA 17mm f/3.5 AT-X PRO which had a good reputation.<br>

</p>

[alan_myers]

<p>Ranier and Lester beat me to it. I was going to recommend the Canon 20/2.8 too. I've been using one for quite a few years now and am pretty happy with it. It's Canon's 'mid-grade' build quality, has USM and uses 72mm filters. It's a little soft in the corners wide open, and like most wide angles can have some chroma aberrations in contrasty lighting (pretty easily dealt with in post processing).</p>

<p>I haven't tried any of the Sigma f1.8 wide angle trio, largely because I've not heard particularly good reports about their image quality, they are all pretty large and heavy, use large filters and all lack HSM (Sigma's version of USM). But, if you need the speed, they are nearly the only game in town.</p>

<p>At 24mm, Canon gives you three to choose from: 24/2.8 ( not USM), 24/1.4L (pricey, and not small/light) and 24/3.5 TS-E (manual focus only... pricey and it's a brick, but tilt-shift is very useful)</p>

<p>If you don't mind manual focus, lens adapters open up a very large world of opportunities. Over the years here have been some superb 17, 18, 20, 21 and 24mm Nikkors, Zuiko, Zeiss, Leitz, Rokkors, Pentaxes, etc., etc... Many of which can be easily adapted for use on Canon EOS.</p>

<p>No one has mentioned the Canon 14/2.8 II... Perhaps because it's a $2000 lens. The earlier version wasn't all that much cheaper, either. Both Sigma and Tamron offered 14/2.8s at one time or another, too. I seem to recall the Sigma got higher rating than the Tamron (but might be mixing that up), but neither was considered as good as the original, but more expensive Canon.</p>

<p>Although I personally prefer prime lenses too, I can't entirely rule out zooms, either. Current 17-40/4L and 16-35/2.8L II are pretty darned good. The 16-35/2.8 II is a bit large/heavy and uses 82mm filters. The earlier version of 16-35/2.8L was decent, but had a propensity to flare I think.</p>

<p>Before these, there was the 17-35/2.8L, which is a lens I have had and used for about 7 years. It's almost identical in size, slightly heavier than the current 17-40/4L. Wide open, it's a little soft in the corners, but it's sharp in the center at all apertures and focal lengths, and sharpens up pretty darned well in the corners at middle apertures. Distortion is very well controlled from 20mm to 35mm. There can be some chromatic abberation - no surprise there - but again it can be dealt with in PP. It was discontinued in 2001 or 2002, when Canon split the line into the lower priced 17-40/4L and higher priced 16-35/2.8L.</p>

<p>Up until around 1995 or '96 there was a 20-35/2.8L. It had a good reputation for image quality, but lacked USM (all the other L zooms mentioned here have USM).</p>

[terry_smith2]

<p>According to the testing done by Chasseur d'Images, Sigma's 20/1.8 is the weak sister of the three wide 1.8 primes. As mentioned above, there is always a noticable gap between center and edge sharpness. Stopping down to 5.6 or 8 gives very good center sharpenss, but the edges are still below average. The 24/1.8 is much better and the 28/1.8 is similar to the Canon version. All take 77 mm filters and all have a clunky change from AF to MF. If you just GOTTA have the 1.8, there's no other choice. If not, the Canon 20/2.8 is a better deal.</p>

[oscar_van_der_velde]

<p>I use my 20mm F/1.8 on the 5D. The sharpness is already very good from f/2, at f/8 there is only slight fall-off of sharpness towards the edges (may depend on your focusing, curvature of field) but it is better than my Canon EF 28/2.8. I see no chromatic abberations. I use only manual focus, for any use you can set it between 1 and infinity and it's sharp. I'm very satisfied with it. The lens exhibits somewhat noticeable moustache curvature of straight lines and its color is slightly warmer than Canon but usually won't notice it. It can focus really close and it has excellent stability on the 5D. I once took a picture at ISO 1600, handheld, f/1.8, 1/10th second with just streetlights, and the picture was sharp. I can provide some full-res samples if you're interested.</p>

[perry_cas]

<p>yeah thanks guys this is interesting. I read the dp review and it isnt favourable. I also read this one at photozone<br>

http://www.photozone.de/canon-eos/297-sigma-af-20mm-f18-ex-test-report--review<br>

which was critical but I thought reasonable.<br>

I have been leaning towards a tokina 17mm at-x pro but it is 2 stops slower and I rather like the bokeh of the sigma...... blah.<br>

I guess there real issue here might well be quality control particulalry for the sigma which makes buying a second hand one a bit of a minefield<br>

How often do you guys use your wides with the autofocus? is it useful on a 20 or a 17?</p>