So I've decided to "go big" in still terms and assemble a set of Leica R primes for my Scarlet-X. In terms of focal lengths I'll probably going to take Matthew Duclos' set as a reference. I'm not very familiar with Leica line of lenses, so naturally I started digging some info along with searching eBay for the lenses I need. What I discovered is that some lenses have different versions, that were released in different time periods.
Here are the lenses that have several versions:
Leica 19mm f/2.8 Elmarit-R 1st version
Leica 19mm f/2.8 Elmarit-R 2nd version — 1990
Leica 28mm f/2.8 Elmarit-R 1st version — 1970
Leica 28mm f/2.8 Elmarit-R 2nd version — 1994
Leica 50mm f/1.4 Summilux-R 1st version
Leica 50mm f/1.4 Summilux-R 2nd version
Leica 50mm f/1.4 Summilux-R 3rd version — 1997
I've also discovered ROM versions of some of these lenses on eBay (the ones that have electronic contacts).
The question is — are there any differences between versions of the same lens except the age of the lens? And is it worth to pay a huge premium (sometimes close to 50%) for a ROM version of the lens if I will still convert it to Canon mount and make it fully manual? Are ROM lenses different from previous versions in terms of glass and mechanics?
If would be great if Matthew himself could answer these questions, but I'm also asking everyone out there familiar with the matter for help.