Japanese lens in Pentax mount
Frame format ― 24×36 mm (35mm SLR / DSLR)
Focal length ― 55 mm
Focusing ― manual
Maximum aperture ― 1:1.2
Aperture range ― 1.2 - 16
Diaphragm blades ― 9
Construction ― 7 elements in 6 groups
Minimum focus ― 0.60 m
Filter size ― Ø58 mm
I am not going to call this article "review" since I am was not doing any chart tests or similar. Rather than that I put this beautiful fast lens on my beloved Pentax MZ-S, loaded it with Kodak Portra 400VC film and headed out to my garden. Luckily everything was in bloom, so I had plenty of things to shoot.
As it was my first time out with this lens, I wanted to see how it handles rendering of out-of-focus areas called bokeh and to see it performance wide open at 1.2 f-stop. All these photographs are shot with the lens Cosina 55/1.2 wide open. They might seem a bit soft, but here is why - the depth of field (DOF) at f 1.2 very narrow (a couple of millimetres) so a slight breeze on flower or branch or me not holding the camera steady (I should have used the tripod, but I was kinda lazy) could throw the focus off. And plus, it is a general truth, that the best sharpness of the lens is when stopped down a bit. With Cosina 55/1.2 that would be about f 2,8 I'd say. But then, why buy fast lenses if to use them stopped down?
When I was deciding over the purchase of a fast lens I had two favourites - this one Cosina 55/1.2 and Pentax A 50/1.2. If I could I would buy both of them, as each has its own advantages. But finally I have choose Cosina because of the bokeh rendering a it's focal length 55mm. I already own a 50mm Pentax lens 50/1.7 and also 43/1.9, so the 55 was something I didn't have. But the biggest thing that won me over to Cosina was its bokeh. It is so special, I can't explain it. Some photographs look like paintings. It is not that smooth as the bokeh of Pentax 50/1.2, but it is so interesting and unique, that ever since I saw some photos I was sold.
If you wish to see more photographs taken with this beautiful lens, please visit my Facebook page and search for SPRING PhotoAlbum.
Katarina Souto Mera