I've read on one of the forums somewhere.. maybe here, a post from
Sandy King describing how he calibrated his NuArc exposure unit so
that one "unit" equaled 1 second. I've been trying to do the same,
but am having a hard time getting it to work. My unit has an "eye"
mounted on top of the brackets that hold the lamp in place. The
eye is in a cylindrical black housing that can be tilted at different
angles. It also has a disk mounted over the eye... this disk can be
rotated, and as it's rotated, the eye is totally exposed, then gradually
the eye is blocked more and more by black paint on the back of the
disk. I assume this is for adjusting the sensitivity of the eye, and
therefore, the value of one exposure unit.

I hope Sandy sees this thread because it's all his fault I've opened
up this particular can of worms! :o)

Can anyone shed some light (har har) on this little gadget and how
to adjust it? Sandy just talked about aiming the eye more or less
toward the lamp, but with my unit, the eye seems aimed at the
metal brackets above the lamp, and I can't see where it can... "see"
the lamp at all, no matter how it's adjusted.