Vivitar 28mm wide angle lenses were made primarily by Kino Optical (Kiron), Tokina and Komine. There is a plethora of different versions see link below. The Kiron versions have serials 22xxxxx, the Komines 28xxxxx serial numbers, the tokinas 37xxxx serial numbers. This review page is specifically for the f2.5 swappable TX mount Tokina made versions. Robin Parmars' list (link below) is a little unclear: his T93 is the earliest one, T4 mount, all metal ribbed focus ring. This was succeeded by ones with rubber focus rings: this lens, the f2.5 58mm filter T91, TX mount, and the 52mm filter, more compact, f2.8 T92. His T94 is actually a t-mount lens that looks similar to the T93.
I have also seen a fixed mount 52mm filter 37xxxx serial f2.8 28mm that looks basically the same as the
tokina RMC (or SL) 28mm, this is not even in Parmars list.
First T4 mount version, f2.8 (R. Parmars' T93) listed
here.
Komine versions
here.
F2 "close focus" komine listed
here.
F2.8 "close focus" komine version listed
here.
Kiron versions, later versions by Tokina (37xxxxx) and Cosina (9xxxxxx) need/have a separate listing.
58mm filter
Swappable TX-mount, PK-M (TX) and M42 (T4/TX) mounts available.
PDF of a T4 mount user manual here.
PDf of a TX mount user manual here.
f/2.8-16, no half stops.
8 aperture blades.
Focus throw ~ °, anti-pentax rotation.
Minimum focusing distance ~0.8ft/25cm
Weight without mount g
There are a large number of vivitar 28mm variants. They are listed in
this blog. This is T91
T4 M42 mount mod described
here (second post March 20 2009).
How to make a TX- PK mount work on a T4 lens (it will fit but you can't move the aperture ring) - see
this thread.