Originally posted by hcarvalhoalves
Maybe it's a rebranded Vivitar Macro 70- 210mm f.3.5 that was made cheaper by losing one stop? I know Cosina manufactured Vivitar lenses. This could be a later-introduced version that was intended to be cheaper, or they intentionally made it slower to avoid competition with their contractor.
Thank you so much, hcarvalhoalves, you made my day. I would never thought to go that direction. My lens looks exactly like Vivitar Macro 70- 210mm f.3.5.
One thing that still bugging me is that I can't find any info on f4 version. Although thanks to you eventually i will get there