It's a no-brainer: get one with the D40, and in the USA you have no choice because that's the only way the D40 is sold. Featuring a high-precision aspherical lens element, the lens compensates for chromatic aberrations that can occur while zooming to deliver high-resolution, high-contrast imaging performance. If you need a cheap WR lens for occasional usage in rainy conditions or if you want a cheap wide angle lens this, or the DA counterpart, is a reasonable choice, but if you can spare the money you will probably be more happy with a DA 20-40mm or a DA 16-85mm lens in the long run.

uwalover -- can you explain to me why someone would have THREE lenses which cover the same focal length range? Ok being picky it has a bit of barrel distortion at 18mm, and it has a teensy bit reduced contrast compared to some other lenses in it's focal length range, but hey it's just a hundred quid! Being a variable aperture lens means that wide open exposure settings are going to change as the lens is zoomed to the longer focal lengths. f/8, f/11) increases or reduces the amount of light reaching the sensor by a factor of 2x (a big deal). Best is to get a grip on the inner barrel (preferred) or turn the focus ring in M mode until it reaches the end of its travel before twisting the lens hood to its desired position.

When shooting at slow shutter speeds, best results are achieved if a pause of a second or two if left between focusing and taking an image. My copy of this canon lens also had a terrible zoom ring that was loose around 35mm and tight and difficult to adjust around 18mm and 55mm.

The USM, I, II USM and II are similar, differing in the focus motor type (the I and II appearing only as kit option lenses, i.An aspherical lens element delivers crisp, high contrast images - even with the aperture fully open. At wide apertures, this lens does a nice job at avoiding flare effects even with the sun in the corner of the frame. At 55mm, nearly 100% of my 18-55mm IS II handheld images are without camera motion blur at up to 1/13 second exposures. The manual focusing ring isn't very well damped, and feels quite loose in operation, which can make applying fine focus adjustments a little harder than it may be, as the focus ring is very easily nudged. The focal range from 18-55mm (wide angle to short tele) is a good fit for a kit-lens because you get a feeling for what focal lengths you actually need or like.