Some sample pics of Voigtlander color skopar 21mm f4 taken by me with Tmax 100 and Tmax 400.
以上一些图是由福伦达21 4所拍，配合柯达Tmax100 和Tmax400， 具体哪张是哪个分不清了，反正100度反差小一点，400度反差大一点。冲扫是画英雄做的，国内的影友应该知道，扫是诺日士扫的。
This lens is not rare at all. It supplies in both Leica M and thread mount. Interestingly, the bayonet edition do NOT sold with viewfinder. And thread edition do sold with viewfinder but you need a adapter to use on rangefinders with M mount. So, if your don't mind the difference of the focusing tab. The tradeoff is straight forward. I prefer the one with focusing tab, but does a super wide lens really need that?
这个头并不少见，有卡口和螺口的版本。卡口的不配取景器；螺口的有取景器但是你要买个转接环才能用在M口的机身上。两个版本镜头外观还是有差别的，主要是对焦拨杆。这个头本身具有快速对焦的能力，配卡口版本月牙形的对焦拨杆更是如虎添翼，但是一个广角头，还要看外置取景器构图的，真的优势微乎其微。
The other significant difference between bayonet and thread edition is the lens hood size. The thread edition equipped the lens hood has the same diameter with the lens itself, which is 39mm. The bayonet one is sightly bigger. When I was using the thread edition one on my rangefinder, I didn't even aware that my finger sometimes block the lens slightly until I processed the film. So be more cautious with your finger. The bayonet one has larger size lens hood which, I think, is a great improvement.
两个版本另个重大区别是遮光罩。螺口版的遮光罩外口也是39mm的，与镜头一样；卡口的遮光罩外口稍大于39mm。当我使用在我的旁轴上使用螺口版的时候，我毫无意识有时候我的手指会挡住一部分右下角画面，所以使用的时候要谨慎一些。所以卡口半稍稍增加了遮光罩尺寸对于这点来说是一个较大的改进。（其实主要是我tm把我的a7卖了我也不能直观地说改进了多少）
Overall, it's a great lens, at $400, for film.
总之，屌丝胶片良心头。
P.S. The following pic is taken by Sony a7 and this lens. Despite of the colored edge, the sharpness at the corner is not that good.
P.S. 下面这图是由此头配Sony a7所拍，除去红移不说，边角锐度比较糟糕。
原图链接 Original Image：https://farm4.staticflickr.com/3698/13834610844_0a190269b4_o.jpg