I was asked about sharpness at f/2.5 so I took a couple of handheld shots.



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Both are not cropped, exposure lightly nudged in Lightroom (0.36 and 0.48 respectively)

Link to Gallery holding all shots for original sizes[

Images of the actual lens

PK Mount

Freshly back from a service, cleaned and lubricated.
Not as common as the 90 f/2.8 and probably a basis of the Vivitar Series 1 90 f/2.5 but without the Series 1 bodywork. It has a serial beginning with 28 which signifies Komine which were one of the best of Vivitar's sub-manufacturers. Reason i'm selling? Bought a Voigtlander 90 f/3.5

Couple of samples taken on Sunday using the same setup used for the standard lens comparison.



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These are not crops and larger sizes can be seen by clicking on the link under each image.

Exif is incorrect because I did not change it between lenses, but I assure you it was taken with the 90.
I will post shots of the actual lens this evening but it is in great shape with no markings and hardly any brassing. Aperture blades are oil free and optically perfect.
Looking for £100 shipped, payment via Paypal please.

Thanks for looking,
Robbie

Cool. Needle and thread applied to results? What does that mean

I mentioned to Robin earlier that even with the Live View zoomed in at 10X magnification, it felt like less than a 2mm on the focusing rings could take you in or out of optimal focus at the distance we were working with. The other thing that stood out was the relatively prehistoric DPI on the camera screens compared to a modern smartphone such as a Galaxy 4 with 441 DPI. That combined with better zooming would be quite handy in these scenarios.

Did you find an A then recently?
Don't know about the Steinheil Munchen Quinon but the Voigtlander and Zeiss both have good to great reputations. I'm beginning to wonder if the DA*55 might have them all covered (in the 50s only arena excepting close focus and macro) but that is a question for another day

Kicks and giggles for me

I know the A is the best fast 50 in f/1.2 (PK) format if only by a smidgen over the K. Could be the extra blade, could be an improvement in coatings. I am not aware of any changes in the optical layout.

I was surprised at how close the rendering of the Cosina 55 was though. It goes softer faster in the OOF areas and i'm seeing ghosting in some areas where the Pentax's are not.

Used prices also suggest this, good A's command €450, K's around €375, Cosina, I'd put at €250-75 now because it only allows you to stop down in Full Stops which I was frankly gobsmacked at. Can't begin to understand the thinking behind this at Cosina.

Mirror lockup and remote on K-5, cable release on Pen.

Sharpness is one factor, bokeh is another, as is ghosting, haloing and flaring. Micro detail recorded is another interesting aspect as well as how easily or well the camera allows you to use such a lens. I can see different aspects showing through in each of the crops shown here.
For example, on the Cosina, top leaf on the main flower, slight ghosting being shown here. Also look at colour transitions.