Again two pics shot with the Porst f/1.2 55mm.
I noticed that the lens performs much better in daylight, without strong light sources within (or close to) the frame.
Though it appears that the results are not as sharp as the photos posted by PepperberryFarm.
My example shows no haze and no external physical damage, the only little fault is the uneven focusing ring (quite loose at one end and too hard at the other end).
It should be noted that there were at least three different versions of the Porst f/1.2, one M42 and two PK. The last PK version stops down to f/16 maximum, instead of f/22.
I have no idea if there were significant differences between the three versions. Presumably at least the coating should have been improved...
Here there two very similar shots. I thought i had taken them at two different apertures, cause the exposure changed... actually it was only due to different lighting/perpective. The data pin didn't short with the lens mount, and actually both pics were taken wide open!
Porst (Cosina) Color Reflex MC f1.2 55mm, on Pentax K-1:
Correct focusing makes a great deal of difference. Better focus in LiveView, and take into account that the SR is automatically disabled.
At first i was surprised that unlike other super fast 50mm-ish lenses, the sharpness didn't improve that much closing 3 1/2 stops (from f/1.2 to f/4). I was wrong because all the photos were actually shot at /1.2!
After i realized my error i tried to shoot a test picture at f/1.2 and then at f/4. There is plenty of difference, sharpness improves a lot!
These shots were taken at minimum focusing distance, i should also try the lens close to infinity. It could make a difference...
The Flickr originals are resized to 40% and the lens data is added to the EXIF using Lens Tagger, as i usually do.
Originally the lens showed as "M42 lens or no lens", while the originals of the photos posted by @PepperberryFarm show "A Series Lens", and the aperture set to f/0. I guess the lens is either different or had the paint scratched where the relevant camera pin touches the lens mount.
EDIT:
tried with a little dot of aluminium foil glued to the lens mount at the right place, and voila': now green button works stopped down, and the EXIF shows "A Series Lens"
cheers
Paolo
Last edited by cyberjunkie; 11-29-2017 at 01:29 AM.
Reason: edit after checking green button procedure after data pin shorted