In the past, when I was working in a photo store, the aversion towards other than original lenses (especially Sigma) was really overwhelming. A common malady of these lenses was that the same lens types differed from piece to piece and sometimes fell apart after half year of usage.

This is a classy lens for APS sensor cameras in every way. Build quality is first rate with smooth zoom and focusing action. It is a perfect match for my Canon 70D (or a 7D) Image quality stopped down is razor sharp with virtually no distortion or vignetting.

Excellent build and image quality

One needs to use this lens with care due to the shallow depth of field

I replace my Tamron 17-50 f2.8 by this lens and I do not regret. It is sharp and on my D7100 it is a perfect match. The only negative comment, it is a big and heavy lens compare to my Tamron.

Sharp; price f1.8

Weight

I replace my Tamron 17-50 f2.8 by this lens and I do not regret. It is sharp and on my D7100 it is a perfect match. The only negative comment, it is a big and heavy lens compare to my Tamron.

Sharp; price f1.8

Weight

Great Lens. Still quite sharp wide open. even better at 2.8. Solid build not too heavy. Has a72mm filter wish it was 77mm. Overall 5 stars

Sigma's 18-35mm F1.8 DC HSM ($800) is a formidable piece of glass if you're looking for a medium focal length (short, if you're shooting full frame), wide aperture add-on for your DSLR, provided you've got the budget for an $800 lens.

Terrific image quality; Wide f/1.8 aperture; Snappy autofocus

Short zoom doesn't do much; May be overkill for APS-C users; Flaky lens cap

When it was announced roughly a year ago, Sigma's 18-35mm f/1.8 DC HSM Art lens was the first of its type with a constant f/1.8 maximum aperture. Designed exclusively for cameras with APS-C sized sensors, it covers the 35mm equivalent of 29-56mm on Canon DSLRs and 27-52mm on other bodies.

Sigma's 18-35mm f/1.8 DC HSM is part of their DC series of lenses designed for APS-C-sized sensors so the imaging circle is matched to the size of the sensor. For this assignment, I used a Canon EOS 60D with a 22.3x14.9mm sensor, producing an equivalent angle of view of a 28-56mm lens.

The Sigma 18-35mm f/1.8 DC HSM lens is built for APS-C format cameras, providing a 27-52.5mm equivalent full frame field of view. At 1.78 lbs, the lens is not quite a bear; however, you'll definitely notice an increase and size and weight from other variable aperture zoom lenses built for APS-C...

Sigma 18-35mm F1.8 DC HSM is a Fixed aperture Auto Focus (AF) Standard Zoom lens with APS-C / DX max sensor coverage, and it is designed to be used with F(DX) Mount cameras. What type of photography is the Sigma 18-35mm F1.8 DC HSM lens good for?

Autofocus, Distance Scale, Hood supplied, Full-time Manual Focusing, Internal Focusing, Fast Aperture at Wide end, Fast Aperture at Tele end, Constant f1.8 aperture throughout the range, 9 Diaphragm Blades for Smooth Bokeh, Minimum focus distance of, 0.28m / 11.0 inch, No Weather Sealing

Autofocus, Distance Scale, Hood supplied, Full-time Manual Focusing, Internal Focusing, Fast Aperture at Wide end, Fast Aperture at Tele end, Constant f1.8 aperture throughout the range, 9 Diaphragm Blades for Smooth Bokeh, Minimum focus distance of, 0.28m / 11.0 inch, No Weather Sealing