I was browsing through some of the old stuff left over from the 1980s and found 2 items that I owned at some stage but cannot recall now what I bought them for. They are 52mm and 58mm "Servo VII" rings; they look like step-up or step-down rings, except that the thread on both sides of each ring is the same. For the life of me I do not know why I bought them but they look well used. Any ideas what these rings might be for?
Are you sure they're not Series VII, in which case they're retaining rings for holding in unthreaded filters: cf: http://silverbased.org/series-filters/ Cheers, R.
Might be. But it definitely says "Servo VII" on them. I owned a lot of Cokin filters in the 80s and early 90s but do not recall ever having unthreaded circular filters. Moreover, these rings have the same (52mm or 58mm) thread on both sides.
Another thought: I vaguely recall people mounting two lenses face to face for macro, cf. http://www.school-of-digital-photog...ling-rings-for-extreme-macro-photography.html Cheers, R.