voia兄
谢谢鼓励！俺是来学习的。

纯粹之美！

SMC PENTAX-A 1:3.5 15mm
Pentax K10D

SMC PENTAX-A 1:3.5 15mm
Pentax K10D GP

看帖不仔细啊，我在楼下说了，PK口有三个版本，分别是SMC PENTAX 1:3.5/15，SMC PENTAX 1:3.5 15mm ，SMC PENTAX-A 1:3.5 15mm。

你帖的属于第二个版本。

貌似还有其它版本，比如下图这个
距离标尺的地方设计和lz的不同，lz是否知道这个头的情况？

※※上，这枚镜头有3个版本（Takumar除外），最早的版本确实是AL设计，这点可以在Contax同样规格的15/3.5上找到答案，但是当时限于技术条件，AL手工研磨镜片非常困难，当然那个时候也不像现在，摄影还是一个比较专业的活，量也不大，后来随着逐渐的普及，需求增大，宾得重新设计后就没有再使用非球面镜片，客观的来说成本肯定是降低了，但是到底哪个更好，就仁者见仁了。

我手上正好比较过这2种版本的15/3.5，供参考：

Pentax SMC K15/3.5AL VS A15/3.5

溯源：

The following is based on research done by Dario Bonazza and published in Spotmatic magazine, number 29 from July 2001.

At Photokina 1972 Pentax and Carl Zeiss showed prototypes of a 15mm f/3.5 rectilinear lens with remarkably similar optical designs. In fact, the only noticeable difference was that Zeiss' lens employed only spherical optics while Pentax's made use of one hybrid aspherical element. In 1974 both prototypes became production lenses. Pentax's SMC TAKUMAR 1:3.5/15 was virtually identical to the prototype from 1972 whereas Zeiss's lens used the same optics but employed floating elements, probably for improved close-performance.

Here the story gets really interesting and a bit unclear. Pentax was of course proud of their aspherical optic, and did mention it in some early lens brochures. However, shortly afterwards they decided that the production of the aspherical element is too expensive, and started developing an alternative optical formula based solely on spherical surfaces. The aspherical element was no longer mentioned in any Pentax publication, but until the new optical design was ready, all 15/3.5 lenses were based on the original design. The first 15mm lenses based on the new design were produced in October 1975, about four months after the introduction of the K-mount. For a short period of time, screw-mount and K-mount lenses were produced in parallel, so Dario believes that a total of about 900 Takumar 15/3.5 lenses were produced, 400 of which employed aspherical construction. On the other hand, only about the 100 of the SMC PENTAX 1:3.5/15 were aspherical. The remaining SMC PENTAX 1:3.5/15, all SMC PENTAX 1:3.5 15mm and all SMC PENTAX-A 1:3.5 15mm are based on the spherical optical formula.

In order to compensate for the lack of aspherical surfaces in the second optical design, Pentax changed several of the optical elements, including the size and curvature of the front element. The exact differences or measurements, however, are not known.

发现：

lenses with the name SMC PENTAX 1:3.5/15 and a distance-scale that includes a 4-foot-mark have one aspherical element.K15/3.5ALA15/3.5实拍：

老帖子被顶起来了，拜读一下！
我也关注过15/3.5，有老外说早期非球面镜的版本才是更好的版本，后来的则是为了降低成本之作，称不上改进。不知道V大是否同意呢？

欢迎，继续！

好片非常多！要学的东西更多！顶一张！

好片非常好！ 学到了很多东西。

小小的遗憾是，进贴之前以为是Hologon那支，想开开眼界的

没想到P家的镜头也如此出色！

想要一个啊,,,,,,,,,,,,,,,牛

受voia的毒忍不住入了个，真是难得的好头，分辨率反差色散畸变不在偶手上的lecia R19之下，现在发现pentax很牛的一个地方就是可以转接到ef口的全副数码，装上去后超级广啊，呵呵，可惜平时用中焦多，广角总是拍不到其他兄弟那么好。

上些片，去新疆玩拍的

受voia的毒忍不住入了个，真是难得的好头，分辨率反差色散畸变不在偶手上的lecia R19之下，现在发现pentax很牛的一个地方就是可以转接到ef口的全副数码，装上去后超级广啊，呵呵，可惜平时用中焦多，广角总是拍不到其他兄弟那么好。

上些片，去新疆玩拍的

http://pdyz02.mofile.com/p/1/2007/8/19/GV/GVYJ02KWRU_105_1024_768.jpg

http://pdyz02.mofile.com/p/1/2007/8/19/PW/PWA9FX7AP1_105.jpg

http://pdyz02.mofile.com/p/1/2007/8/19/MN/MNY8SSVE7A_105.jpg

受教

有区别 CZ的那只近摄很出色但畸变大不适于拍建筑

voia兄，被毒到了，偶也想买个这个头，想了解下边缘成像和色散，不知可否将100%原图的边缘部分裁一块放上或者发MAIL给偶？多谢了。

F4光圈和F8光圈的便可，谢谢，[email protected]

让我想起了著名的香格里拉，现在都成啥样了

刚从云南回来,滇池就是这么令人扫兴,不光是表面一层绿藻,连摩托艇开过翻起的浪花都是绿的.

滇池这颜色有点吓人啊

黄昏

滇池

昆明真不错，上海连个像样拍荷花的地方都没有

不知不觉已经过百贴了，谢谢大家的支持！

[voia 编辑于 2006-08-09 10:28]

昆明大观荷塘的雨后

昆明标志性古建筑-金碧坊

交代一下作品的时间，地点，器材有利于大家相互交流

自然是在昆明咯。

支持！

漂亮的画面

收藏＋创作！