i have a 21c, tessar ( 3.5 .. ) on my series D
its a fast and sweet lens .. i must admit though
i don't use it much, i have a RR named laverne
purchased from davela many years ago
that roosts on the series d these days ...
its funny, these seem like they would be such a big bulky camera, these 4x5 slrs
but they are perfectly weighted. i usually do 1/15 handheld work with mind
have fun !