Re: [Leica] Fluorescent filtration

[Malcolm McCullough <blayne@mbox2.singnet.com.sg>]

>Try though I will to avoid it, I may find myself in a situation soon
>where I will be shooting chromes under fluorescent lighting.  What are
>the popular recommendations for on-the-fly filtration.  I'm not going
>to have the time to carefully correct the lights; I just need to tone
>down the green.  Anyone have experience with the B+W FL-Day?  What
>about a CC40M?  (No one seems to have off-the-rack 39mm and 46mm
>CC30M's).
>
>Thanks,
>Rob Schneider
> 

I shoot a lot of chrome under fluorescent and use a Minolta Color Meter for
gauging the correct filtration (I do a fair bit of film work as a Director
of Photography and a colour meter is standard kit). To begin with I got a
few Lee polyester CC10M, CC20M and CC40M filters and cut them to fit inside
the front of each of my M lenses. After a while I found that the 10M and
20M covered just about everything that I was shooting, so I ordered these
from B+W in the relevant sizes. They took months to get to Singapore. I
recall that CC30M is not listed in the Lee or B+W catalogues, but I could
be wrong there.

I had better mention that I used both daylight and tungsten film, depending
on the colour temperature of the light. Generally the tubes which have a
lot of green also have a lot of blue - there is a good reason for this -
and therefore suit daylight film. Some cheap tubes need about 40M and run
at around 7000 K. The tubes with less green suit tungsten film more than
daylight. Of course, I am making sweeping generalisations based on the
tubes commonly used in this region (SE Asia). The degree of filtration is
also dependent on how much of the flourescent look you wish to preserve
(like Mark says, green skin is in). It is not possible to correct strong
green/blue fluorescent casts across the whole spectrum using filters - the
green and blue spectral peaks are very sharp in the emitted light, which
sharpness is not matched by the spectral response of the filter. Or to put
it another way, tubes with a strong green/blue cast generally also have a
poor Colour Rendering Index. I always prefer to slightly under-correct if
in doubt because a slightly green picture looks more true to reality than a
slightly purple one (that's my opinion anyway).

I would suggest buying a few Lee polyester filters and testing if possible.
You could either use them in front of the lens as I did, or temporarily
stick small bits of them behind the lens with Scotch snot tape (sorry, I
can't remember the official name/number). Anyway, you could cut a 39 mm and
a 46 mm circle out of a 100 mm filter - and they are about 7 bucks each. If
you have difficulty I could post mine to you, already cut to those diameters.

If you can get to see the printing on the tubes (Warm White etc.) you could
then use Kodak's recommendations for filtration. These are available on
their website.

Regards,
Malcolm