Nice Work Peter
Hi Tony, here are some reactions to your various questions based on my experience.
28-90mm – avoid unless you're ok with it NOT being parfocal. In other words if you adjust the zoom after focusing on something, that something will quickly be out of focus. Most of the other Leica R zooms are parfocal and don't exhibit this issue.
70-180mm vs 80-200mm – Both are excellent choices but for me the 70-180mm wins hands down. The advantages are: Resolution, character, speed and APO correction. The 80-200 feels compact by comparison and has a much friendlier price tag, which are the 2 advantages that come to mind. Supposedly it tests sharper than the Canon f4 equivalent too.
80mm vs 90mm APO Asph vs 100mm APO Macro – 3 completely different beasts (apples/oranges/bananas). Each are great at what they do and I think the 90 APO Asph is often overlooked by cinematographers since its newer, pricier and a stop slower than the 80 Lux. It renders gorgeously though and is the same optical design as the current M version (though it may be a hair crisper due to the larger glass). While the 100 macro is a benchmark for performance, it does have a super-long 720-degree focus throw which I've found isn't as convenient for run n gun as the others. Great for the studio and as a dedicated macro though. If possible, try all 3 before deciding which one(s) to buy... then maybe you'll end up with all 3 like I did
35-70 F4 is a solid mid-range zoom. I've found its more of a work-horse and not as sexy as some of the others, but great to have when you need it. Now the 35-70 2.8 Asph is sexy but super expensive and in my experience not 100% par focal but close (seems to be from 39-70). On the wide end the 21-35 3.5-4 zoom is an attractive option too.
135mm is an excellent option, especially for the price. Not as crisp as the 100 macro (though few are) but has more character and is a solid lens in that focal range. For better performance, I'd go with a newer one and check the coatings on the elements as this lens is prone to separation.
For serial numbers its more important that they're consistent for color-matching than anything else (ie within a few years of one another). After testing many many from various years, I've found the later ones tend to be a hair sharper (and that goes for the 100mm macro too) but there's probably more variation between samples in general than there are between specific production years due to things like de-centering, optical damage, debris build-up in the optics, etc. Also later ones tend to have less focus drag and just feel/behave more like a real cine-lens than older vintage glass.
Hope this helps...cheers!
