I have a 100mm Symmar convertible, if that helps. It's not MC, though.
But there are smaller Schneider lenses: 80mm Symmar, 65mm Angulon, 50mm Xenar... Maybe you mean "smallest Schneider lens that gets close to covering 4x5"? The 65mm Angulon would still be a candidate, for a given value of "coverage". And it's is a tiny little 00 shutter!
It's a Schneider 100mm f/5.6 Symmar-S MC which the vintage chart from Schneider indicates that it will cover a 2x3. I am not sure yet that it will cover a 4x5. I want to put one on my Busch C 2x3. Have you used it in the convertible configuration? This one isn't marked on the Copal 0 shutter as a convertible but neither is my Schneider Symmar-S 210. Any idea of what the conversion would be in length?
Do you know of any Bjorndahl's in Norway?
Everytime I find a film or paper that I like, they discontinue it. - Paul Strand - Aperture monograph on Strand
Maybe you mean "smallest Schneider lens that gets close to covering 4x5"?
Just FYI... The 150mm f5.6 Xenar covers 4x5 with a bit to spare. It takes 34mm filters and comes in a Copal No. 0 shutter. The 150mm f9 G Claron is nearly as small (35.5mm filters, Copal or Compur No. 0) and covers 5x7 with movements. If you find one in a late style all black Compur 0 shutter it will only weight about 135g. Both of these are smaller than the 100mm Symmar-S and cover more.
It's a Schneider 100mm f/5.6 Symmar-S MC which the vintage chart from Schneider indicates that it will cover a 2x3. I am not sure yet that it will cover a 4x5.
I have one of these and it is a very nice lens on 6x9 (cm), allowing reasonable movements. It won't quite cover 4x5 (in.), but works well as a gentle wideangle on 6x12 (cm). Schneider quotes the image circle as 143mm at f22.