was not the end. The previous problem of having the parfocality
upset overnight returned. Each morning I would fiddle about for
10 mins or so and would finally get the parfocality right again,
but this happened every morning. I wondered if the cause might
be there some movement in the microscope itself during the time
it was getting warm from the quite hot lamp housing in the base
of the microscope. For three consecutive mornings I checked and
the parfocality was out overnight, as previously, but I simply
left the microscope switched on for 20 mins and would return to
find parfocality was restored!
I have included
photographs of the Charles Krebs flash set-up with the microscope...
flash used in this setup is a Vivitar 283 with a custom-designed
output control unit designed by Charles Krebs. The flash burst
is directed to the sub-stage condenser by a plane piece of glass
held 45° over the field condenser...TLW