Originally posted by Alizarine
they're co-designed, not rebadges... as far as I remember.The Tok had a tripod collar, the Pentax had none (but is AW and has SDM)
The announcements and rumors want they shared optical formulas, not co-developped or co-built anything. Some designs (amongst whom 16-50, 50-135, 100) were from pentax, others (like 12-24) from tokina. They differed notably in AF system and coating (each using its own system). This was a really good thing as SMC was really superior to what tokina had to offer (to be fair, it is their only serious flaw).
Each compagny built their own lenses based on those designs, without help or interference of the others.