I haven't shot my Heiland with my 4x5 and Ektar 127 yet, but I shoot M3 bulbs with my 1950s Canon IVSB rangefinder. It's for fun factor and nostolgia really. I still find them cheap. A couple weeks ago I got 6 boxes of M3 an M3B rubber banded together at a thrift store for $5. That's 14 cents a pop.