Đánh giá lens canon 70 300 is usm năm 2024
(From Canon lens literature) The EF 70-300mm f/4-5.6 IS USM telephoto zoom lens has been developed to meet the high-performance standards that today's photographers demand. Improved Image Stabilizer Technology provides up to three stops of "shake" correction, and the "Mode 2" option stabilizes images while panning with a moving subject. Compared to the original Canon EF 75-300mm IS zoom lens, this telephoto lens has faster autofocus, and overall the lens is lighter and has a smaller diameter than the original. The zoom ring can be locked at the 70mm position, making this powerful lens easy to transport, too. Test Notes Every now and then, you really do get more than you pay for, and the Canon EF 70-300mm f/4-5.6 IS USM is proof positive of this. When we ran this lens through its paces in our lab, we were flat-out astonished by the optical quality it delivered. Were it not for the largely plastic body construction, we'd say that Canon has mislabeled this lens: It really delivers L-glass performance. That plus a very effective image stabilization system make this an amazing bargain at its typical street prices of $600-650 US. (As of this writing in late September, 2006.) On a sub-frame body (we tested it on an EOS-20D), it delivers excellent sharpness from corner to corner, across most of its focal length range. It softens slightly at 300mm and f/5.6, but stopping down to f/8 returns it to excellent sharpness. Softness due to diffraction limiting begins at about f/11 though, so its sweet spot is a little narrow at 300mm. Across the rest of its range though, it's simply outstanding. Its other characteristics are very good also. Chromatic aberration is quite low shooting wide open, increasing moderately as you stop down. Geometric distortion is quite low, ranging from 0.23% barrel at 70mm to a maximum of 0.27% pincushion at 300mm. The inflection point (where geometric distortion passes through zero occurs) just under 100mm. Light falloff in the corners of the frame ("vignetting") is very low through out the full range of focal lengths and apertures. It hits a maximum of 0.13 EV at 300mm and f/5, but is never more than 1/10 EV anywhere else, and is unmeasurably low at most settings. While we don't have any quantifiable way of testing image stabilization performance, Canon's prowess in this area is well known, and the IS on the 70-300mm seemed to work very well in our limited playing with it. If you haven't shot in limited lighting with an IS lens or camera body, you're really missing something - It's hard to overstate the difference IS makes when you're shooting hand-held under anything but bright daylight. There really aren't any weak points to this lens optically, unless you count its rather slow maximum aperture range of f/4-f/5.6 against it. It does suffer in the build quality department though, with a rather plasticky feel and very lightweight construction. When you zoom out to 300mm, its front element projects a long ways out from the body, which could present a hazard from knocking it against things. Our sample also did show some zoom creep, so when carrying it around your neck, you'd be well advised to use its zoom lock to keep it from sliding out. The only other limitation we noticed was that its front element rotates when focusing, which would make it awkward to use with polarizers or graduated neutral density filters. Bottom line, while it has a few minor limitations, and has rather small maximum apertures, the Canon EF 70-300mm f/4-5.6 IS USM is one of the outstanding bargains of Canon's entire lens lineup. Full-Frame Test Notes: As surprised as we were by this lens' performance on the sub-frame EOS-20D, we were even more surprised by how well it did on the full-frame EOS-5D, at least in terms of sharpness. Despite the much larger sensor area it had to cover, sharpness was really excellent across the entire frame, at all apertures and focal lengths (although the slight softness wide open at 300mm was still quite apparent). Thanks no doubt to the 5D's larger pixels, chromatic aberration was actually lower at shorter focal lengths than on the 20D, but was noticeably higher at 135 and 200mm. The 70-300mm had the most trouble on the full-frame body exactly where you'd most expect to see it, in light falloff (vignetting) and geometric distortion. The distortion curve was almost an exact duplicate of the one from the 20D, simply magnified. Maximum barrel distortion at 70mm rose to 0.57%, while maximum pincushion at 300mm increased to a very noticeable 0.73%. Vignetting also increased pretty dramatically, but was still less than that found on many lenses. The maximum light falloff was right around a half a stop at all focal lengths, decreasing to less than 1/4 EV when the aperture was stopped down one notch. All these defects can be corrected to a reasonable approximation in Adobe Photoshop CS2 with the Lens Correction filter. For a more complete correction, DxO Optics Pro supports this lens on a variety of Canon bodies, but unfortunately not on any pro models, such as the EOS-5D, 1Ds Mark II, 1D Mark II N, etc. (DxO does support the 70-300mm f/4.5-5.6 DO IS USM on pro bodies, but not the conventional non-DO model we tested here.) While it does show a few more foibles when attached to a full-frame body like the EOS-5D, the Canon 70-300mm f/4-5.6 IS USM is still an excellent bargain, particularly if you're willing to spend a little time in Photoshop tweaking its images. CanonEF 70-300mm f/4-5.6 IS USMCanon EF 70-300mm f/4-5.6 IS USM User Reviews8.3/10average of 39 review(s) Build Quality7.2/10 Image Quality8.5/10
9 out of 10 pointsand recommended by snapper (6 reviews) sharp from 70 to 300mm, also with 1.4x TamronSP TC, 3+stop I.S. ability, accurate focus, price long, less mech stable when extended, no FTM focus, color/contrast slightly weak, 5 feet closest focus I find this lens useful as a LONG walkaround... I want to shoot flowers, birds and faces. a good compliment to the 17-85 - but better image quality. VERY clean images no real issues except speed - f5.6 @ 300mm. The focus system at the front is shakey.. and seems a bit flimsy. This is a lens to get in the habit of manually retracting focus and locking it when walking/moving ...it is long and wants to get 'hit' by things. Just needs a little attention to that because of less robust mech design. BUT it gets flowers, and faces so very nice.. seems to need a SLIGHT boost in saturation - but NOT sharpening (70-300mm). The only way-to-go in this range... you really will love I.S. - to grab the far shots - with at least 3 stops of stabilization. |