Durst recessed enlarger Lens Board (Siriotub)

thingiverse

This recessed lens board accommodates several Durst enlargers, including the M370, M670, M605, and M707 models. It's engineered for use with 50mm lenses or shorter focal lengths where achieving focus is impossible with a traditional flat board. The board features a 38.4mm non-threaded hole that fits snugly around a 39mm lens thread. To secure the lens, I had to heat the hole slightly to soften the plastic, then carefully screw it in place.