Tungsten & Par queries
Posted 06 February 2014 - 02:47 AM
Posted 06 February 2014 - 10:51 AM
If your 6K and 4K PAR's are HMI's, not tungsten, you should get modern flicker-free electronic ballasts.
The problem with short shutter angles and standard 50 or 60 Hz AC magnetic ballasts is that when the shutter time is 1/50th for 50 Hz or 1/60th for 60 Hz, you get two pulses per frame, so when the shutter time is 1/100th for 50 Hz and 1/120th for 60 Hz, you get only one pulse per frame -- so the lamp might not flicker but it might look dimmer depending on where you catch the waves in their cycles.
I'm assuming you are shooting with a crystal sync motor on your film camera or are shooting digital.