Sigma 15-30mm f/3.5-4.5 EX DG Reviews

This lens serves a dual purpose, as a wide angle for portraits and as a general walkabout lens on a DSLR.

The optical quality is good, with a little softness and visible chromatic aberrations towards the corners wide open. Stopping down only a thirs of a stop virtually eliminates these problems.

Focusing is performed internally, and AF is quick as you would expect on such a wide lens.

The large bulbous front element is either a blessing, or a curse. Flare and ghosting can be a problem when the light source is just out of the frame, although I like to exploit this sometimes. Deliberately placing the light source can lead to fantastic coloured effects, but if you dont want that, you'll be frustrated very quickly.

Minimum focus is nice and close, which means you can get in close and maximise wide-angle distortions.

I heve a "no DG" version of this lens, the sharpness is better than canon 16-35/2.8 L, but the sigma have too much flare. I cannot use it to counter-light, and I have to be carefull with spotlights in scene.

This is one of the sharpest lenses i've ever owned. It fantastically liberates a full frame photographer. Once you own it, you'll terribly get used to the freedom it offers. This is my primary lens now for landscape and inhouse photography. I use it with my Pentax *ist film camera which I believe is the best AF SLR Pentax had ever manufactured including the more expensive mz-s. Pity they're all discon now. Anyway, one has to pay extra attantion when working with full frame (CCD or film) cameras because the ultrawideness fools the cameras' exposure meters. You should either only use spot metering on your target to measure correct exposure and then use AE-L (lock exposure) while composing the picture or use an individual lightmeter such as Gossen or Sekonic. Otherwise if you rely on multi segmented exposure measurements of your camera you'll probably underexpose your pictures.

In addition to my previous review i would like to mention the filter issue.

Again for a full frame photographer there is no way you can attach a standard filter on the front. Forget about the push on attachment ring with 82mm threat comes along with the lens. It starts vignetting (gets into the picture frame) from 25mm. If you attach a filter on it, together with the rim of the filter i assume you can not go any wider then 28mm. So forget it. The gelatin filter holder at the bottom is one thing i'll never use. So there is only two solutions.

1) You can buy a Cokin X-PRO series holder and X-PRO filters (13x10cm) But you have to use an universal attachment ring that clamps on the lens's barrel.

2) Hold a big X-PRO filter with your hand.

I own it about a 1 1/2 year. Very good quality for it's price ~300 euros(now, payed x2 when I bought it "new").
Works well indoors.
Good for landscapes. There are some problems (as described above, filters - flare).
Can be used for portraits only on a non-FF DSLR (20-30-40 D) where it becomse a ~25-48)