I wanted a solid walkabout lens for my D5100 without breaking the bank. I had the option of buying the Nikon 18-300 for about $1000 or a 3rd party lens. I really did't want to invest too much in glass for a D series mount as I can see myself moving up to an F series in a couple of years.

"This is a very nice lens for travel. It will increase my reach and give me macro option as well. It balance well with D5100 body very well. It feel good on your hand.Another plus is the price, almost 50% less than Nikon's 18-200MM.

Very quality lens, half the price of the similar nikon model. Very good sharpness at F8-F11, at almost all focal lengths. Small and light, OS is working well. Compatibility problems with the new nikon bodies.

Sharp!; Good close up; OS working well; light and small; price

Compatibility problems; creep when unlocked

Like all super zoom lenses, the Sigma 18-250mm f/3.5-6.3 DC OS HSM Lens features a to-die-for focal length range . Sigma packages this 13.9x (250mm divided by 18mm) focal length range in a very well built , modestly-sized , reasonably-priced APS-C-only lens with quiet, fast AF and optical...

There is an underlying desire in every travel or street photographer to be able to carry one lens to cover all contingencies.

Very versatile walk around lens. just like carrying 18-55 + 55-250 with a tripod.

good built quality; effective OS; HSM motor; very good IQ between 18-80

quiet heavy; average IQ between 135-200

The barrel has a large zoom ring and a small manual-focusing ring at the front, with a zoom scale marked at 18, 24, 28, 35, 50, 80, 135, and 250mm. The three switches on the barrel include Zoom Lock, AF/MF, and stabilization ON/OFF.

Sigma's DC 18–250mm f/3.5–5.6 Macro OS HSM lens is designed to be an all-in-one lens and the focal length is one of the widest available on the market. It was specifically designed for use with an APS-sized sensor, which makes it more like a 24–300 lens, depending on the crop factor of the camera...

Light; Big zoom range; Pretty good image stabilization

Soft edges; Significant chromatic aberration

Very convenient lens. Get this one with my 500D is a nice combo. No need to change between the 17-55 IS and 70-200 L as before. I can leave the two lenses at home and travel light with only one lens. IQ is OK.

Very useful zoom range; fast and near silent focus; reasonably sharp from 18-80 mm

Very convenient lens; Get this one with my 500D is a nice combo; No need to change between the 17-55 IS and 70-200 L as before.

The barrel has a large zoom ring and a small manual-focusing ring at the front, with a zoom scale marked at 18, 24, 28, 35, 50, 80, 135, and 250mm. The three switches on the barrel include Zoom Lock, AF/MF, and stabilization ON/OFF.