![]() The ring takes about ninety degrees to go from 70mm to 300mm, and does not show any signs of zoom creep. The zoom ring is the larger of the two, rubber with long segmented ribs, measuring about two inches wide. The lens features a focusing scale in feet and meters (in a recessed and windowed scale) but does not feature an infrared index or a depth-of-field scale. On the Sony mount Vibration Control is not available, because Sony cameras include image stabilization in the body. On the Canon and Nikon mounts, there are two control switches on the barrel: one to enable or disable autofocus, and one to enable or disable Vibration Control. The lens features a metal body mount and a smaller filter ring size (62mm instead of 67mm) composed of plastic threads. No doubt this is a result of adding four new lens elements in three groups, as well as the whole Vibration Control (VC) system and the new USD focusing system.ĭespite all these changes it's still light enough to use comfortably without a tripod. The lens is significantly larger and heavier for a start, adding an inch to its basic length and 12 ounces to its weight. The Tamron 70-300mm ƒ/4-5.6 VC USD looks attractive with its matte black finish and polycarbonate construction it is a new breed of telephoto zoom lens from Tamron, and not just an incremental upgrade from its previous incarnation. The new lens offers an adequate 0.25x magnification at 300mm, with a minimum focusing distance of around five feet. Unfortunately, the new lens design no longer offers the 0.5x magnification of the previous design. Focusing operations do not rotate the front element, making life that much easier for polarizer users. The new system allows for full-time manual focusing, allowing the user to adjust autofocus results by simply turning the focusing ring. The lens focuses very quickly - it takes about one second to go through its focusing range - and it does so nearly silently. Tamron has employed a new focusing system with this lens, the Ultrasonic Silent Drive. As usual, this distortion is much more significant when the lens is used on full-frame cameras such as the 1Ds Mark III. From 135mm and on, there's significant pincushion distortion in the corners. At 70mm, the distortion is almost negligible - just a slight amount of barrel in the corners. There's some distortion present in images shot with the Tamron 70-300mm ƒ/4-5.6, but no more than other lenses in this category. To remove the impact of corner shading you need to stop down to at least ƒ/8. At its worst, you're looking at extreme corners which are almost a full stop darker than the center - you see this at 100mm and 135mm when used wide open. On the 1Ds Mark III however, it's a different story: you have to stop down significantly to get images which don't show some kind of light falloff in the corners. CA is more noticeable as the lens is stopped down, offering the best performance at 135mm and 200mm.Ĭorner shading is virtually non-existent when the lens is mounted on the sub-frame 7D. ![]() The Tamron 70-300mm ƒ/4-5.6 VC USD offers good but not great CA tolerance, with some light magenta-green fringing appearing in areas of high contrast in corner areas. Otherwise it's mostly the same story as above - stop down to ƒ/8 to get maximum sharpness, and don't expect anything overly sharp at 200mm or 300mm. Mounted on the full-frame Canon 1Ds Mark III, the lens doesn't betray any secrets - it's just a little bit softer at wide apertures. The 70-300mm ƒ/4-5.6 VC USD stops down to quite small apertures, in this case, ƒ/32-ƒ/45, all of which will provide quite soft images, with the exception of ƒ/32 at 70mm, which provides only slightly soft images. Performance isn't any better at 300mm ƒ/8 and ƒ/11 are the best settings here, where they provide adequately sharp images. You have to stop down to ƒ/8 to get past this, to what amounts to actually quite decent sharpness it doesn't get any better at ƒ/11. At 200mm the lens begins to show signs of weakness, with a bit of a soft center at its widest aperture of ƒ/5. The mid-range of the lens (100-135mm) provides similarly good performance again, very good at ƒ/5.6, and almost tack-sharp at ƒ/8. Diffraction limiting sets in at ƒ/11, but it's still quite sharp, until ƒ/22 where we begin to note some generalized softness across the frame. At 70mm and ƒ/4, the lens is quite sharp, with some light corner softness in the top right and bottom left corners stopping down to ƒ/5.6 provides almost tack-sharp results (some very slight softness remains in those corners), but at ƒ/8 it's essentially tack-sharp. With the lens mounted on the sub-frame Canon 7D, the lens produced some exceptionally sharp images, more towards the ''wider'' end of 70mm than when zoomed in fully to 300mm. The lens ships with a petal-shaped lens hood, takes 62mm filters, and is available now for approximately $450 in Canon, Nikon and Sony mounts. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |