The 105/2.8 Xenotar is a fine lens that covers 6x9cm and may have come in a high-speed Synchro-Compur shutter like the one I use on my Tech V 23b. Unfortunately my shutter is missing the high-speed booster spring, but maybe I’ll get around to dealing with that some day. It’s still good up to 1/100 sec. It’s certainly usable wide open, but I usually stop it down 1-2 stops when I’ve got enough light, if I don’t need more DOF.