Originally posted by timw4mail The one I have is a "Vivitar Series One". Not sure its really from that series, but it's a 4/4 design, with a 67mm front filter.
I do imagine you are correct about example variance.
not sure what Vivitar Series 1 lens is being discussed here
this is a great site about the Series 1 70-210 zoom
Vivitar 70-210 Series 1 Macro Zoom Lenses - Mark Roberts Photography
Vivitar Series 1 70-210mm Macro Zoom
The cult classic lens
Page topics: Specs - Compatibility - Resolution - Serial #'s - Sample Photos
Introduction
In 1975 Vivitar introduced the "Series 1" line of lenses. They were intended to compete with the best offerings of the major camera manufacturers, albeit at a very high price -- they were quite expensive even by OEM standards. Nonetheless, discriminating photographers who could afford the price snapped them up and they are still much sought-after by photographers willing to give up auto focus in return for top quality optics, construction and versatility.
The most famous of the Series One lenses was the 70-210 macro zoom. One of the first zooms to offer any kind of macro capability, it offered outstanding optics in a highly versatile package. There were several versions produced over the years, the first three of which are still very desirable lenses. The last two manual focus versions are of poorer optical quality and are aren't really comparable to the earlier versions.
After the five versions shown here, Vivitar sold some really poor lenses under the "Series 1" label, which all but destroyed the prestige of the brand. Any of the autofocus "Series 1" lenses should be avoided, as should any of the ones that have maximum apertures of f/4.5-5.6.
this also might be of interest
https://www.robertstech.com/flange.htm