( 2 reviews )
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Posted: 02-14-2008
I bought a used 15-30mm EX lens on Ebay late last year and have been using it on an SD14. Image quality depends on what focal length along its narrow zoom range that you use. At the widest end (15mm and F11), image quality is simply splendid. Great contrast, color and resolution with a sharp image running right off either end of the frame with sharp corners. Depth of field is enormous at 15mm, even when just set to infinity, resolving sharp near-foreground and distant background elements together. There is a small amount of CA which seems to increase a little as you focus closer than infinity. There is some distortion, but this is not apparent in landscape shots. That said, image quality begins to decline in the mid to longer end of the lens, at any F-stop, though F16 or more helps. At 30mm, the middle portion of the image is very sharp, but resolution become somewhat demolished at the margins and image corners. Shooting 30mm at F16 makes things acceptable, but results are not as stellar as the wide-end performance. The lens is big and so somewhat awkward, but surprisingly light for its size. Auto-focus with my copy is inconsistent (often focusing well past infinity), so I just put the lens in manual (a two step operation) and set infinity by hand. The bulging front lens element will produce flare in images if struck by sun or strong light. I keep the lens cap ring attached to the fixed lens hood, which greatly shields the lens and does not induce any corner light fall-off when used on an SD14, even at the widest 15mm setting. And I cup my hand beyond the hood to block light when shooting more toward the sun. This seems to work well. Any flare is usually visible in the camera viewfinder, so you can adjust what you can to block it before taking a picture. Lens flare is one of the major cautions for this lens in various reviews. In practice, I've had no trouble with flare, though keep the problem in mind. For all practical purposes, I stick to the wider end of the lens (15 to 19mm or so) and try not to have to shoot below F11. So restricted, I've found it to be a great lens for landscapes. It produces excellent images--the end results often showing far more to a scene than expected.
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( 1 of 1 found this review helpful ) Posted: 02-14-2008
I bought a used 15-30mm EX lens on Ebay late last year and have been using it on an SD14. At the widest end (15mm and F11), image quality is simply splendid. Great contrast, color and resolution with a sharp image running right off either end of the frame with sharp corners. Depth of field is enormous at 15mm, even when just set to infinity, resolving sharp near-foreground and distant background elements together. There is a small amount of CA which seems to increase a little as you focus closer than infinity. There is some distortion, but this is not apparent in landscape shots. Image resolution is very good at all focal lengths--but from 19mm through 30mm, the aperture needs to be stopped down to F14 to get the best corner resolution. Image distortion and CA diminish at longer focaL lengths. The lens is big and so somewhat awkward, but surprisingly light for its size. Auto-focus with my copy is inconsistent (often focusing well past infinity), so I just put the lens in manual (a two step operation) and set infinity by hand. The bulging front lens element will produce flare in images if struck by sun or strong light. I keep the lens cap ring attached to the fixed lens hood, which greatly shields the lens and does not induce any corner light fall-off when used on an SD14, even at the widest 15mm setting. And I cup my hand beyond the hood to block light when shooting more toward the sun. This seems to work well. Any flare is usually visible in the camera viewfinder, so you can adjust what you can to block it before taking a picture. Lens flare is one of the major cautions for this lens in various reviews. In practice, I've had no trouble with flare, though keep the problem in mind. It produces excellent images--the end results often showing far more to a scene than expected. F11 seems to be the ideal aperture for 15mm, but F8 works in a pinch in low light. Addition 10/11/08: I've determined that the ideal infinity focus point with this 15-30mm lens varies with the focal length. I don't trust the auto-focus still and manual focus everything. The lens focus ring set to its infinity mark works perfectly for landscape shots at 15mm. But for 20mm and 24mm, the focus ring should be turned inside the infinity mark about 1/16th inch or more. Corner resolution of images improves markedly doing this. At 30mm, the focus should be set just inside the infinity mark on the lens focus ring. Image results are even better now than my earlier review above. With considerable use now and nice results, I'd give this lens 5 stars.
