|
以下这东西是在某个网站上转帖过来的，据说是一个玩了几十年宾得的发烧友对大部分镜头的评测，大家可以参考一下：（我就没有能力全部翻译了） 18mm K18/3.5 is an excellent rectilinear lens; it is quite large and bulky though. It's correction of spherical and coma aberrations seems far better than that of A20/2.8, and it is surprisingly sharp edge to edge. Its coma wings are also smaller than those of K24/2.8, K28/2, or K30/2.8. Yoshihiko Takinami also notes that the corner resolution of K18/3.5 is higher than that of A20/2.8, and the only defect of K18/3.5 seems to be the lack of normal or UV filter though it has four filters built-in. BTW, there's no A18/3.5. 20mm Among f2.8 versions of K, M, A, F, and FA lens, A seems to be the best with excellent contrast, color rendition, barrel distortion. OTOH, it's not as good in resolution, coma aberration and contrast in the corners as K15/3.5 or K18/3.5, even closed down. FA version is said to have the same optical formula as the A version, and to be very sharp in the center when stopped down. Not much vignetting , but slight "droplet" distortion was mentioned once. All 20mm lenses are said to have great build and prices to match. K20/4 and the M20/4 produce very slight distortion. K20/4 is also known to flare. However, when comparing K20/4 to K18/3.5, Nikkor 20/2.8 AIS (current model) and Tokina 17/3.5 (current model.), the K20/4 still beats them in every aspect, especially flare control. 24mm K and A 24/2.8's are optically identical. Pentax K24/2.8 is a great lens with very few distortion, high resolution, great color rendition, and good color saturation. There's no M24/2.8. A 24/2.8 is very resistant to flare and ghosting, very sharp when stopped down. A 24/2.8 is reputed to be better than M24-35/3.5 and M24-50. Comparing K(A)24/2.8 and K24/3.5, K(A)24/2.8 has higher center resolution/sharpness and lower corner resolution/sharpness. Both of them are excellent performers. FA24/2 AL IF is said to be an excellent lens, and optically better than both K(A)24/2.8 and K24/3.5. FA version is very well build and exhibits excellent contrast and sharpness. Its handling is very good, especially when used as a manual focus lens due to it's focus clutch mechanism whereby you pull back on the focusing ring, which now has a relatively nice manual focus feel. 28mm Rare K28/2 is an excellent performer. Its resolution and uniformity of image quality in all over the frames are very impressive at f/8 or f/11. (Yoshihiko Takinami) Keep away from M/A/F series 28mm lenses because of their "relatively" poor performance when comparing them to their f3.5 relatives. FA28/2.8 performs only marginally better than its predecessors. Yoshihiko Takinami has indicated that the best 28mm from Pentax, in terms of its optical performance, is the old K28/3.5. The only two defects in K28/3.5 is its size and weight and some light fall-off towards the corners, which seems better than M28/3.5 or FA28/2.8AL in comparison, but it does exist. M28/3.5 is also an excellent performer and is compact in size. Go for K28/3.5 when your concern is performance, and go for M28/3.5, or FA28/2.8AL, when your concern is size and weight besides performance. If you are concerned about distortion, go for the K28/3.5 or M. Distortion is under 0.5% for both. Otherwise, the M(or A)28/2.8 is quite nice in terms of weight and dimensions. The FA 2.8/28 is far better, though, but not 100% distortion-free either. Note: FWIW, there were two versions of the M 28/2.8. The earlier one, with the silver ring on front, was said to be 'slightly' superior. The later version is the 'upgraded' Takumar Bayonet 2.8/28, which now features multicoating. Either one is not as sharp or as contrasty as M 50/1.7 or the M 135/3.5, or the 20-35/4 zoom. 28/3.5 shift lens features good sharpness (a bit less sharp than the K35/2.8), excellent flare control (unless the sun is at the edge of the image), and almost no distortion, although at full shift, there is some slight pincushion distortion barely discernable at the edge. For additional information about tilt and shift lenses, you might want to take a look at this page. 30mm K30/2.8 "is excellent optically; it has well-corrected aberrations, very few distortion, very high actual/visual resolution, good color rendition. K30/2.8 is far better than M28/2 [or] M28/2.8 Look here for more info. "[Yoshihiko Takinami] 35mm K35/2, with 52mm thread size, is the "best K-mount 35/2 lens ever made", because of its sharpness and color renditions. The other "best 35mm that Pentax ever made" are the new FA35/2AL and the old K35/3.5. Both of them are very high resolution lenses with excellent sharpness, impressive color renditions, and very natural bokeh. "Their three-dimensional image descriptions are really amazing."[Yoshihiko T.] Note: FWIW, the "certain" magazine's quality/price/love factor rating for FA35/2 AL was VG/VG/VG M35/2 doesn't have the bokeh of K35/2. SMC Pentax A35/2 is also said to be very good, as is Super Takumar 35/2 (the one with the 67mm filter, it controlled flare well, and seemed nice and sharp at 8x10) 40mm M40/2.8 is the famous "pancake" from Pentax. It was first introduced circa 1975 and became a 揷ult?lens. It is sharp, though not as sharp as your regular 50/1.7. It's very small, and it's aperture and focusing rings are a pain to use. It's definitely not a rare lens as many sellers claim it is, but it's very overpriced and in mint condition usually sells for $200 US dollars or more. 43mm This excellent lens, FA43/1.9Limited, has a character of an old-styled standard lens with excellent modern coating. It is a bit soft wide open, becomes good one stop close, and is very excellent at f/4 or closer. Its flare control seems superb, as does its contrast. The cons are its price and some distortion. 50mm f1.2 Both, K50/1.2 and A50/1.2, share the same optical formula, are optically excellent, have high resolution, good saturation, excellent color rendition, and great bokeh. The difference between K50/1.2 and A50/1.2 is the number of aperture blades; A50/1.2 has 9 blades and K50/1.2 has 8 blades. This results in slightly better bokeh and flare control in the "A" version. It's also been said that 50/1.2 is a little soft wide open especially in the corners. Stopped down, A50/1.2 is an excellent performer at f/8-11 with very high resolution and very good visual sharpness. Its visual sharpness at f/8-11 seems comparable to K55/1.8, (A50/1.2 is better than the K55/1.8 wider than f/8, and similar from f/8 and narrower. However, keep in mind that for high-contrast resolution the "el cheapo" A50/2 virtually matches, stop-by-stop, the A50/1.2 (and beats the K50/1.2), from f/2 to f/22.). The A and K50/1.2's really are nice to use for their focusing ease, and in dim light they may be the only lenses that can do the job at all, but you certainly don't get much "bang-per-buck" while using them under average light conditions. f1.4 Very useful, high quality, normal lenses. There are two different optical designs in Pentax 50/1.4 lenses; one is "K" and "M", the other is "A", "F" and "FA". A version is thought to be slightly better than the M(K) version in terms of corner resolution and image uniformity all over the frame. The A50/1.4 is a great all-around performer. Go for A50/1.4 instead of M50/1.4 if you consider buying a MF lens. Pentax slightly changed its optical design when A50/1.4 was introduced. A50/1.4 is optically superior to M50/1.4 FA 50/1.4 is said to feature good resolution, great color rendition, natural bokeh, and decent MF capability. f1.7 Both M and A50/1.7 are somewhat legendary in their performance, but it's been suggested that their superiority over f1.4 versions is only marginal. Comparing f1.4 to f1.7, FA50/1.7 seems visually a bit sharper than FA50/1.4, but FA50/1.4 seems more delicate/refined especially in colors. FA50/1.7 has a slightly better feel over the F version. Its focus ring has more of a rubber feel, while the F has more of a ribbed hard plastic feel to it. The damping and build quality also seems to be slightly better on the FA version. Optically, these lenses are identical f2.0 There's no K50/2. M50/2 is not as sharp or as contrasty as the A50/2. A50/2 is the best bang-for-the-buck K-mount normal lens: sharp, contrasty, and "dirt" cheap. In resolution, the A 50/2 seems to be only very slightly behind the A50/1.7 50mm Macro M50/4 Macro is good macro lens that can also double as a slow normal one that focuses from macro range all the way to infinity. A50/2.8 Macro is sharp, light, has a very nice feel to it. It's also very useful as a slow normal lens. F50/2.8 Macro is sharper than the A version and the M50/4 Macro, but the focusing ring feels awful in manual focus mode. FA version has the same optical formula as the F version 77mm FA77/1.8 Limited makes a great matching pair with the FA43/1.9 Limited. It has the same cold metal feel, same metallic, whirring focusing sounds, as well as the slide-out lens hood. It features FREE (Fixed Rear Element Extension) focusing system just like A* 85/1.4, the A 100/2.8 Macro, the A* 135/1.8, and (apparently) the A* 200/4 ED Macro. It is said that FREE is good at close-focus ability but is not good at AF because of its increased extension at small focusing distance. "It is really an excellent performer with great sharpness, excellent contrast, and remarkable color rendition. The only drawback I noticed is its relatively poor, but still good, flare control for a modern Pentax lens."[Yoshihiko Takinami, http://blog.sina.com.cn/s/mailto:yoshihiko@takinami.com] It's also reported to be easier to focus than the M85/2 or K105/2.8 |
|
|
