Homebrew PCBs

derekhawkins wrote:
>>There is no need to worry about collimation of the beam unless you 
>>are exposing very large panels. 
> 
> Hear, hear!

I made a UV lightbox with a 125Watt HID lamp (HPR-125) 24" from the glass,
and in a cylindrical parabolic reflector (lamp lays horizontal). 90%+ exposure
happens in 30secs, and i found a good optimum to use is 90secs for
pre-coated negative pcb. The pcb is held against the glass by the lid
that has a layer of sponge.

Without the reflector and beam collimation, you'll need a bigger globe
for the same exposure time.