my review of my month with the Spiratone Plura-Coat by Mitake 28mm f2:
this lens was a whim-purchase from eBay - I attempted to research the lens before hitting 'Buy Now' but there is virtually no information on this lens on the internet...
there are some general facts: Spiratone was a re-badging seller of lenses and other camera equipment, Mitake was a second or third tier manufacturer of lenses for re-badging..... and that is about it...
what scarce info I found suggests that you could also find this lens badged as a Soligor, Formula 5, and possibly other brands...
the copy I bought was damaged from the beginning - it was not described in the ad, but the aperture lever was missing its return spring, so the for the first couple of days I had the lens, it would not meter reliably and I could only shoot wide-open, which gave me little clue about the lens' capabilities - so off to Advance Camera for the repair and CLA...
when returned, the lens meters reliably and I could now shoot anything I wanted to, from f2 to f16 - so off we go!
firstly - this is a late-70's film-era 28mm lens, with some coatings (Plura-Coat) to the elements, but nowhere near current-day standards...
it is a manual-focus (turning opposite Pentax OEM lenses), manual-aperture lens that is all metal and glass; with no plastic or weight-saving composites, this lens weighs a hefty 360 grams (more than my SMC A 100/4 Macro)...
it is a K-mount lens, a six-bladed iris, a 62mm filter ring, and just a bit beyond 180* travel for the focus ring...
the good: color rendition is accurate, the focus ring is smooth and well-damped with no hard or stiff action throughout any of its travel, center sharpness, and the bokeh is pleasant...
the bad: shooting at F2 with any strong light sources is nearly-impossible and requires skill in both the taking and post-processing of the shot, plus almost anything not centered in the shot will not be in focus...
overall: I had fun shooting with this lens throughout the month - once I learned how to shoot with it and what its strengths are, I was able to pull some really nice shots through her and did have one 'Explore' during the month...
some of my favorites from July:
and the one 'Explore':
I can recommend the lens with reservations - firstly, there are better 28mm lenses available (almost ANY of the Pentax K/M/A 28 are going to be a better buy) and there are not many copies seemingly available... so actively searching for it may prove to be more work than it's worth...
if you come across one in decent shape, for a cheap price, sure - but I don't know that I would honestly go looking for one of these....
I had a good month with her, but was bored of her limitations by the 3rd week in July, to be honest, and was looking forward to moving on...
and here's the rest of July's shots:
https://www.flickr.com/photos/pepperberryfarm/albums/72157695429069342/with/43057702864/