Nikon Ai AF DC-Nikkor 105mm f/2D

"DC" stands for "Defocus image Control," or controlling the taste of bokeh in front and back of the main subject. By moving the front group with the ring, you can control spherical aberration exclusively stepwise (up to 5 steps). There're two kinds of bokeh depending on their position: front and back bokeh. Generally speaking, it's hard for a lens to have ideally smooth front and back bokeh at the same time. For example, if a lens had smooth back bokeh, its front bokeh tends to be double-lined or ring-shaped. Therefore, a lens is usually designed by sacrificing the quality of one bokeh to realize higher quality of other bokeh, or by averaging the quality of the two bokeh. Meanwhile, this lens uniquely lets users to choose which bokeh they give priority. Incidentally, when the background is complicated and you give priority to front bokeh with this lens, you can intentionally produce "poor quality" images. Sounds strange? In fact, they look interesting when the double-lined or ring-shaped bokeh are used creatively. Anyway, this lens will make you think deeply about the meaning of bokeh.

( Photography : M.ISHIZUKA & K / Text : K )

This is a shot I gave priority to the front bokeh. And, it looks funky. :)

Following the theory, I gave priority to the back bokeh on this one. And, it generated round and soft bokeh, while the focal plane is very sharp.

The strong compression effect of 105mm focal length dramatizes everyday scenes like this one.