Protecting lens during long exposure

[rpagliari]

I usually do 6 to 8 minutes long exposure, and I'm now trying to do the same with a 4x5 camera.

The lens has an opening to let the shutter cocking mechanism work. Should I worry about it for long exposure, and wrap something around it, or is it separate from the optical path inside?

Thank you,

[Bob Salomon]

Of course it is separate from the optical path. If it wasn’t every shot you take would be fogged!