Archived posting to the Leica Users Group, 2001/06/02
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Eric wrote: > > Frank: > > >If the light source does not have the wavelength present ( or the amount of > >energy in that wavelength is small) it will be impossible to filter the > >light in the way you might want. > > > >This is the reason that flash tubes are generally cold light sources and why > >filtering the flash tube has limited success. > > Is this from experience or from theory? I'd be interested in hearing of > poor experiences trying to filter flashes. In practice, I've found the when > I put a colored filter in front of my flash, that's the color light I get. > For example, I've never put a warming filter in front of the flash head and > have green light result. :) > > If you match your flash to the approximate color temp of the ambient light > by using an ordinary colored gel in front of the flash, it's hard to tell > what's artificial and what's real. Everything becomes real. It sounds like theory to me because in practice the filtering of light sources is common and recommended first before the filtering of optical glass. Put yellow in front of blue you get green. So you don't unless you are just doing black and white. But you put orange in front of blue the magenta in the orange gets the green out out out. The Balcar studio strobes I've been using for 26 years have alternate Pyrex shells of different warmths and UV absorbing capabilities to help it's flashtube which is the coolest one out there from producing to much blue which can make for crossover on the warmest of films. One shell will give you tungsten balanced light to balance with the other light bulbs in the joint. Mark Rabiner Portland, Oregon USA http://www.rabiner.cncoffice.com/