Re: [Leica] Complimentary flash filter

[Donal Philby <donalphilby@earthlink.net>]

George,
Why someone would bother with complimentary color and shoot in BW would
indicate some kind of technical perversity.

Be that as it may, Rosco Plus green and an FLD works well.  On both my
Balcars and the Nikon or vivitar strobes I also add an 1/8 CTO warming
gel (the CTO lives on the small flashes).  You can't use this method,
however, if there is a computer or TV monitor in the sceen, since it
will go magenta.  But I have had to go as much as 60cc Red to get a
color monitor to give a white, so it might work out since most monitors
can use a 20red at least.

One way to figure all this out is with a color temp meter.  You get the
filter you want for your lens and put it over the sensor then get one of
the color sample books from Rosco or Lee and try things til you get same
temp reading with or without the filters.  This works well when doing
non-standard like the 60cc red for which there is no common large size
complimentary and you may have to use more than one in combination.

I have been meaning to make up some filters to live on the SBs and
vivitars.  Here's how:

Cut filter longer than width of the strobe face.  stick Velcro dot on
each side of strobe head.  Put velcro dots (complimentary gender : ) )on
the filter to match and another dot on the other side of the filter so
you can stick another filter on that.  Then they can stack.  If the dot
on the strobe head is in the right place and the filters are the right
length, you can stick one or more across the front and have the rest
over the top, all secured via the dot on the strobe head.  You can keep
several filters stored and ready to go. A typical set might be:
1/8th CTO
Plus Green
1/4 CTO
Full CTO (daylight to tungsten, good for using tungsten film on gloomy
day and flashing the subject while background goes blue)
Polarizing (marked with orientation so you can counter balance one on
camera)

Best to use tape on the gels so they resist tearing longer.  Label each
filter on tape (or computer slide label also works well) so no fumbling.

Few camera stores carry the Rosco or Lee filters, but a good stage
lighting supply will have all of them.  About $5 for 2x3 foot sheet. 
But not optically pure, so only for lights.

BTW, I have an older tri-color meter by Spectra that needs a new home. 
Used primarily by the film industry.  I have things pretty well under
control and don't use it much any more.

donal

Roy Zartarian wrote:
> 
> FWIW, I've put a light green gel over the flash and an FL-D
> (which, I think, = CC30 magenta) over the lens for transparency work
> under fluorescent lights in order to make all the illumination one
> "color" and correcting the green at the lens. A few months ago I used
> this approach with the R4 (now we're on topic) for some publicity
> shots for the local public library.  Although the skin tones were a
> tad on the warm side, the overall results were acceptable.
> 
> Roy
> 
> On 12 Dec 98 at 6:44, George Huczek wrote:
> 
> > Recently I read of a photographer who uses a colour gel on his
> > flash, while using a complimentary colour filter on the camera lens.
> >  I think he had a green filter on the lens, and a magenta gel on the
> > flash, or vice versa. Can someone please tell me what practical
> > differences these filtering techniques have?  I understand the
> > theory of why this works, but I am wondering what differences would
> > actually appear on the photos if one did this.  He was using a
> > standard focal length lens on a N***n to photograph people, using
> > TriX film.

- -- 
Donal Philby
San Diego
www.donalphilby.com