Originally posted by Marc Sabatella So my guess is, any listing for a Vivitar 13/2.8 was a typo, and it's really the same as the Bower 14/2.8.
No on the first part (no typo), yes on the second one (they're the same).
Vivitar has a habit of declaring their focal lengths differently than Samyang. Check the
B&H listing for the amazing 13/2.8. Their fisheye is also 7mm, instead of 8mm.
Opteka went even further with the fisheye:
theirs is 6.5mm!
It's one of the peculiarities of rebranded Samyang lenses.