7 out of 10 points and recommendedusefully conceived, fast and quiet AF, low weight, good build qualitylens hood not included, variable maximum aperture
This is a practical lens, very well conceived: it provides a flare cutting diaphragm, both control rings operates smoothly, the front lens doesn't rotate, and the physical length remains constant while zooming. USM provides really fast and nearly silent autofocus operations.reviewed December 3rd, 2006 (purchased for $400)
Despite its low weight, this lens is well built: it isn't an L class lens, but my specimen performs flawlessly after four years of intensive usage. The optical quality is quite good, but not stellar: at the wide end distortion may be visible, and in some situations borders are quite soft. Flare can sometimes be an issue, but only in rather extreme situations; lens hood is recommended, as usual. In flare and especially in ghosting performances, this zoom outperforms every competitor in its price range.
All in all, this is an honest workhorse, recommended for full frame or 1,3x SLRs: on APS-C sensors, CA and resolution could be disappointing, and the zoom range wouldn't be so attractive.
9 out of 10 points and recommendedvery good optical quality, good bokeh, low weightbuild quality is a little disappointing, FTM worse than ring-type USM
Between f/4 and f/8 this is one of the sharpest lens I've ever seen. Performances at f/1.4 are not stellar: with full frame SLR you'll find a lot of vignetting; especially at corners, you can frequently notice poor contrast and narrow resolving power. Quite often, this is not an issue, because you'll probably use this aperture for portrait work or special effects, when you can push the great bokeh of this lens at its best. Anyhow, the test results you can find in this site doesn't match my field experience, because blur at full aperture is a real disaster here, and seems to show some decentering effect (which usually suggest a defective lens). According to many other lab tests, my field experience shows a usable lens, even at f/1,4. Distortion is visible only with close subjects: it looks more like coma than geometric distortion. Contra light performances are really good; color balance is always neutral.reviewed December 3rd, 2006 (purchased for $320)
The build quality of this lens is decent, but a little disappointing, especially when compared with its optical performances. It provides a micro-USM AF drive including full-time manual override in one-shot AF mode: it proved to be quite fast and nearly silent, but not as practical as the more usual ring-type USM.
All-in-all this is a great lens, highly recommended for both full frame or APS-C DSLRs.
10 out of 10 points and recommendedoutstanding optical quality, superbly fast AF, very easy to handlenone
This is a great lens, it simply performs flawlessly in every situation. Its optical quality is outstanding, and with pro-grade SLRs you can use it with 1,4x extender by maintaining a good quality and AF. AF is lightning fast and accurate; the focus limiter is useful. The build quality is really good: my lens still survives, after years of demanding usage and some... abuse! It isn't sealed, unlike more recent L class lenses. This prime is very well designed: easy to handle, it features a built-in lens hood that I've always found really useful. The lens collar is sturdy and very well built, but I'd like the possibility to lock at 90° and 0° the lens within its collar, with the help of some preset lock system.reviewed December 3rd, 2006 (purchased for $1,000)
An upgrade of this lens could be a good idea, if it would bring IS, a better lens collar and last generation sealing techniques. Anyhow, IS could be not such interesting on APS-c cameras, where the 400mm focal length is equivalent to 640mm, making hand-held photography nearly impossible: rely on a good tripod, instead. On the other hand, IS design would be more complex, getting the lens heavier and probably making worse its optical quality.