I had an unfortunate mishap with my wide-angle lens, so I had to replace it. I chose to try the new Sigma 10-20mm f/3.5 wide-angle lens rather than choose the Tokina 12-24 (sharp but still CA problems, odd AF/MF switching), the new Nikon 10-24 (initial reviews say that at 10mm the IQ is so bad it’s not worth it compared to the 12-24), or the Nikon 12-24mm (expensive). I used to have a Tokina 11-16/2.8 but it was a bit soft and the focal range is too narrow for me, so I didn’t consider that lens this time. I thought the new fixed maximum aperture design of the Sigma (the older version is f/4-5.6) might lend more Image Quality, so I tried it.
I’m no official lens tester, but since I seem to have a fairly early copy (B&H and Amazon showed it as pre-order status, got mine from Adorama) I thought I would take some sample images and share them. I shot some images of a fence at different focal lengths and different apertures. I used my D300 and used a tripod for each shot. I shot using 14-bit RAW then loaded the files in Photoshop CS4 using Camera Raw 5.4 with all settings zeroed out (no adjustment to RAW data).
Sorry the images aren’t perfectly straight. I decided not to re-do them because this set shows the distortion of the lens. The images are a bit under-exposed too – sorry.
People buy lenses like this for the widest focal length, so I tested that first.
10mm f/3.5 100% crop, center of image
10mm f/3.5 100% crop, top right corner
10mm f/5.6 100% crop, center of image
10mm f/5.6 100% crop, top right corner
10mm f/11 100% crop, center of image
10mm f/11, 100% crop, top right of image
10mm f/22 100% crop, center of image
10mm f/22 100% crop, top right of image
I’d say at 10mm the lens isn’t super-sharp, and there are some noticeable CA areas that need to be fixed in post. It’s really wide, though. I’d rate it at 6/10 at the 10mm length, since the issues can mostly be fixed in post.
I’ll show 14mm next, since that was my widest focal length with my old lens.
14mm f/3.5 100% crop, center of image
14mm f/3.5 100% crop, top right corner of image
14mm f/5.6 100% crop, center of image
14mm f/5.6 100% crop, top right of image
14mm f/11 100% crop, center of image
14mm f/11 100% crop, top right corner of image
14mm f/22 100% crop, center of image
14mm f/22 100% crop, top right corner of image
So, IQ seems to be quite noticeably improved over the 10mm focal length. I rate the lens at 14mm about 7.5/10. The 10mm-12mm focal range seems a bit softer than the rest of the focal range of the lens. Aperture-wise, the lens is a bit soft below f/5.6 and there’s a bit of diffraction at f/22, so I will probably be using this lens from f/5.6 – f/16. For landscapes, I’ll probably use something in the 12-14mm range, at f/11 or f/16. I don’t think I would use the 10mm length unless I thought I couldn’t make the shot without it and was willing to spend the extra time in post.
Distortion is something that can be fixed in Photoshop, as are the chromatic aberration issues, so very nice images are possible with this lens as long as a bit of post processing is involved. Here’s a shot that shows the CA issues:
12mm f/8 200% crop – There is some purple fringe on the top of the hinge, and some green/yellow color on the bottom of the hinge. It’s there, and it’s a problem, but it’s fixable.
One interesting note with this lens – it focuses extremely close! I thought my Nikon 14-24 was good at getting close, but this lens is ridiculous. I was able to get a shot at 10mm with the lens (hood) about 1.5 inches from the fence! That’s probably 1 inch closer than the Nikon would do.
Overall, I give this lens 7 out of 10. The focal range is excellent for ultra-wide on a crop-sensor camera, and the fixed aperture is a nice improvement. The lens hood mounts easily. The focus ring is stiff, but I love that it will auto-focus while you hold the ring (like Nikon AF-S lenses) and I probably won’t do much manual focus with this lens anyway. The zoom ring is smooth and well-damped – not too loose, not too tight.