The next big purchase..?

I'm having trouble deciding what I should buy next for my photography loadout. Of course, simply buying new equipment and goodies will not make you a better photographer over night - it sure does help though :). I've narrowed down what I want to a lens in the portrait focal length of around 85-90mm.  The real question now is should I get a film lens or a microfourthirds lens...

If I go the film route, I will most likely purchase the unsung Leica 90mm f/4 Elmar rigid.  If I can find the Elmar f/4 collapsible for the right price, I may opt for that one instead.  I love the 50mm focal length of my Canon-Serenar f/1.8 but the close focusing limit is quite a nuisance.

The 50mm works well for environmental and full body portraits; focusing gets annoying when trying for a head-shoulders frame.  If I was shooting the 90mm FOV, I'd have an easier time framing and focusing tighter shots.  My only qualms about buying another film lens is 1) I can't use it for my newspaper work, and 2) do I even shoot portraits that often?

If I treated myself to some microfourthirds glass, I would pick up the legendary Olympus 45mm f/1.8 lens.  Microfourthirds can struggle at times with shallow depth of field, but the Oly 45mm fixes that problem with flying colors.  Because of the 2x crop factor of the smaller sensor, the 45 turns into a 90mm equivalent field of view on full frame/35mm film.  The great part about grabbing this lens is that I can use it for the newspaper, but also my own personal work.

My 12-50mm f/3.5-6.3 covers the 45mm focal length, but it just does such an abysmal job at it.. At the 45mm length, the widest aperture the lens will allow is along the lines of f/6 or f/6.3.  Because of the smaller sensor, you end up with a 90mm FOV with the equivalent DOF of f/12 on a full frame sensor.  F/1.8 will give me an equivalence of f/3.6 which is perfect for my usage.  I get the low-light magic of f/1.8, but a wider depth of field leaving a margin to catch focusing errors.

If I do end up getting the Oly 45mm, then two-thirds of my microfourthirds trinity (14, 25, 45) will be achieved.  I think I will augment my OM-D with the Panasonic 14mm f/2.5 pancake down the line.  At the moment, the kit zoom I have suffices that need fairly well.

Wow, wasn't that geeky?  Here's the TL;DR:  I'll have more fun with the Elmar, but the Olympus glass is more practical.