ML 100mm 3.5

It's delightful piccie.

The lens is an oddball for the Contax Zeiss series; it was a commercial failure and ended up being heavily discounted by retailers.

Open-wide it's not the sharpest (though it shows superb contrast) but from f5.6-11 it's a very good performer indeed.  I think it fell into a 'no man's land' within the Contax range as, being a short telephoto, many people already had an 85mm or 135mm, both of which were faster and sharper in all versions, so why bother with a 100mm? Zeiss had already produced the outstanding f2 version and a dedicated macro lens in that focal length but with cameras getting smaller and lighter, Zeiss made the decision that a cheap, lightweight lens would find a market - they were wrong. However, they've sort of had the last laugh as it's become increasingly popular since production ceased. Prices became very steep and only now are beginning to slip back to better reflect it's position within the Zeiss Contax pantheon of glass.

I used one occasionally but never bought one; I always preferred the f2 lens - infinitely sharper and a better build quality (it needed to be with that extra weight and floating element!) - and the extra speed wide-open, creating a more shallow dof, made it perfectly acceptable for portraiture under natural lighting.  It now has a very strong following and, being compact, is ideally suited to today's DSLRs and CSCs; only yesterday I got into conversation with a charming young lady who was sporting the natty little lens on her Fuji X-Pro.  She loves it and was kind enough to show me some of the images - they were impressive.  That was enough to persuade me to consider buying one, if the prices realign more closely with those for the 135mm f2.8, as it takes little space in a bag and is unobtrusive enough for street photography.  Your delightful photo adds further weight to the argument in favour of the little Sonnar.