As I hoped to shoot inside some of the ancient buildings, and I didn’t expect to be allowed to use a tripod, I rated the HP5 at EI1600, a two-stop push from box speed.
My favourite shots of the trip were taken inside the Chapel of Kings College. A chapel is normally a small building but this chapel, having been built for use by Kings between 1464 and 1515, is the size of a cathedral and has the largest fan-vaulted ceiling in the world.
If I remember correctly, the shots were taken at 1/60s with apertures of f4 or f5.6.
I have sometimes shot the Yashicamat at 1/30s or even 1/15s but I wanted to minimise the risk of camera shake.