Đánh giá tokina 12-24 f4 if năm 2024
At 12mm @ f/4 the lens shows very noticeable vignetting (~1.4EV) which will be visible in most scenes. At f/5.6 the problem is already largely reduced (~0.78EV) but stopping down a little further may be a good idea if required. At 18mm and 24mm vignetting is far less pronounced even at wide-open aperture. One stop down vignetting is already quite negligible here. Similar to the distortion characteristic vignetting is again more intense on the D200 (1.5x crop) vs the EOS 350D (1.6x). MTF (resolution)The Tokina showed very impressive resolution figures in the MTF lab. Unlike many other lenses with a reduced image circle it was capable to combine a generally excellent center performance with very good borders and still very good extreme corners. The center performance decreases marginally towards the long end whereas the borders improve slightly. If anything the rather significant drop in quality at 12mm f/11 may be worth a critical comment but then you rarely need to stop down beyond this setting due to the already extreme depth-of-field at this focal length. The field curvature is quite moderate. Please note that the MTF results are not directly comparable across the different systems! Below is a simplified summary of the formal findings. The chart shows line widths per picture height (LW/PH) which can be taken as a measure for sharpness. If you want to know more about the MTF50 figures you may check out the corresponding Imatest Explanations (From Tokina lens literature) The AT-X 124 AF PRO DX lens is Tokina's first lens designed for use exclusively on Canon and Nikon Digital SLR cameras having an APS-C sized sensor. This lens gives the Digital Photographer an ultra wide-angle zoom lens that has the equivalent of an 18-36mm zoom range on a 35mm film camera while maintaining a bright constant aperture of f/4. Professional Features: Non-rotating 77mm filter threads mean special effect filters will not change when the lens' focus is changed. Tokina recommends using HOYA PRO 1 Series low profile filters with the AT-X 124 PRO DX. Fast internal focusing with Tokina's One-Touch focus clutch mechanism allows the lens to AF focus faster and switching between auto and manual focus is as easy as snapping the focus ring back and forth. 2 sharp-cut aspherical elements accurately correct aspherical aberration usually associated with ultra-wide angle lenses. Bright, constant f/4 aperture allows plenty of light to enter the camera for shooting in a wide variety of photographic situations. Chrome plated brass mount plate and all-metal zoom unit can stand up to regular use while advanced polycarbonate outer lens barrels reduce the weight of the lens, making it a pleasure to carry. Test Notes This lens is Tokina's first foray into the world of reduced image circle optics, and it's an excellent effort. From 12-20mm, it shows just excellent sharpness across the frame, even when wide open. Its performance suffers somewhat at the 24mm "tele" end of its range, but stopping down to f/8 cleans up the problems there quite well. Chromatic aberration is on the high side at maximum wide angle, decreasing steadly to moderate to low levels at 24mm. Exposure uniformity is quite good, particular for such a wide-angle lens, with a worst case vignetting of 1/2 stop at 12mm wide open, dropping to 1/4 stop at f/5.6. Performance at f/5.6 at all longer focal lengths tested was 1/10 stop or better. Geometric distortion is probably this lens' weakest point, but even there it's no worse than one might expect, reaching a maximum of roughly 0.75% barrel distortion at 12mm, decreasing to about 0.4% at 15mm, and dropping to almost zero at 24mm. We found this lens to be a very pleasant surprise, particularly given its relatively modest price point. It delivers excellent performance wide open across most of its range, and its troubles at 24mm are easily corrected by stopping down. All in all, a great little lens, nicely compact thanks to its reduced image circle, well built, and optically much better than its modest price would lead you to expect. Tokina12-24mm f/4 AT-X 124 AF PRO DX SDTokina 12-24mm f/4 AT-X 124 AF PRO DX SD User Reviews8.5/10average of 41 review(s) Build Quality9.1/10 Image Quality8.2/10
9 out of 10 pointsand recommended by killersnowman (10 reviews) sharp, wide, great build, relatively cheap, constant f/4, great hood, very little CA flares in bright light, but what UWA doesnt? I am not one to go and test all my lenses by taking "test shots" of targets and seeing the lines per inch or any other meaning less statistic. on the other hand i do a more practical test: i use the lens the way i would on a daily basis. The first thing that i noticed on this lens is the amazing build quality; the finish is nice and smooth yet not plasticky and when you hold it in your hand you know that you are holding something serious. When i first started using it the zoom ring was a bit tight but has loosened to a comfortable level since then. the focus ring had no such problems. The focusing is smooth in manual and fairly fast in auto; although it really doesnt have to be very fast because of its wide nature. one point of interest is that the length of the lens does not change when focusing or zooming, although the front element moves about 3mm back and forth when zooming. The lens felt very comfortable on my 20d. the lens hood is a pettle type (its felt lined to boot!) and does a pretty good job except for when the sun, or a bright light source, is right on the edge of the frame. The Pictures! the pictures taken with this lens are quite amazing. the constant f/4 aperature is extremely usable and i did not notice very much vignetting (even at f/4). The color and saturation are quite impressive although i ended up messing with the colors and saturation in PP to bring the most out of the lens. I did not notice anything good or bad about the contrast -- it just works, nothing to get excited about for the contrast. |