View Full Version : Legacy Lenses Vivitar 28mm/f2.5 - Konica mount

07-27-2007, 04:44 AM

Description Vivitar 28mm 1:2.5 "AUTO WIDE ANGLE", Konica AR mount - although as far as I know, it was produced in several other mounts as well. Bought it for approx. $35 in a second-hand photo store; it had been there for so long that the layer of dust on the front element was nearly opaque.
The photos above were taken with unfinished modification for the 4/3 bayonet - the locking hole is missing. I made the spacer from 1.4mm thick aluminium and fixed it with two-sided sticky tape since I was too lazy to mill harder metal and find necessary screws. Also, I took off the scratched front nut with all the text (it doesn't really hold anything) and screwed on a protective filter in its place.

- 28mm fixed focal length
- Aperture adjustable from f/2.5 to f/16 in full stops only (rather inconvenient; I modified this mechanism to operate smoothly)
- 62 mm filter size

I haven't shot any test charts, but the lens is a bit soft when fully open; starting from around f/5 it becomes sharp enough. I haven't noticed any corner blurriness, but there's cyan/purple fringing in the corners at all apertures (requires ~ -30 fringe correction in Adobe Camera Raw) and some vignetting.

- 28mm is equivalent to 56 mm on a 4/3 camera - a very close approximation of a "normal" lens
- no adapter needed - just an aluminium ring and some skills
- inexpensive
- looks rather intimidating for 28mm

- heavy; heavier than the kit 14-45
- chromatic aberrations (see above), although this can be fixed
- can exhibit lots of lens flare due to huge front element (see example below)
- aperture ring clicking mechanism can go "sproing" when you unscrew the rear flange

Here's a rather extreme example of lens flare:

Overall I think this qualifies as "mediocre". Not a lens I like to carry with me at all times.