OT: Why are floodlamp gels gel ?

[N_Cook]

Went to clean a gel and the gel came off leaving clear celluloid or whatever
substrate.

Trying to dye varnish with red ink or dye only gave pink when applied to a
lens, with white shining through. Some floodlamp gel gave a proper red
colour. Is ther a general priciple here that if gels were dyed clear sheet
,throughout , they would be less coloured or less transmissive for the same
colour intensity?

 

[Ron]

On 11/02/2010 10:30, N_Cook wrote:

Went to clean a gel and the gel came off leaving clear celluloid or whatever
substrate.

Trying to dye varnish with red ink or dye only gave pink when applied to a
lens, with white shining through. Some floodlamp gel gave a proper red
colour. Is ther a general priciple here that if gels were dyed clear sheet
,throughout , they would be less coloured or less transmissive for the same
colour intensity?


If the colour came off, it wasn't really a proper theatrical colour

filter. The name gel stems back to a time when colour was made from a
coloured gelatin based liquid poured out into a flat tray and left to
set. they were thick and unstable, prone to fading, shattering and
catching fire.

Later on, filters (theatrical types just call it colour) were made from
an acetate material which didn't handle the heat very well, This was
known as Cinemoid, also prone to fading and melting.
These days, proper theatrical colour filters are made with a very
complex process involving two or more layers of polyester and
polycarbonate. They still burn out, specially blue! Darker greens
wrinkle up for some some reason.


There is some very interesting reading on the Rosco and the Lee Filters
websites

Ron

 

[N_Cook]

Ron <ron@lunevalleyaudio.com> wrote in message
news:aq-dnUzC_pqtaO7WnZ2dnUVZ8kGdnZ2d@bt.com...

On 11/02/2010 10:30, N_Cook wrote:
Went to clean a gel and the gel came off leaving clear celluloid or
whatever
substrate.

Trying to dye varnish with red ink or dye only gave pink when applied to
a
lens, with white shining through. Some floodlamp gel gave a proper red
colour. Is ther a general priciple here that if gels were dyed clear
sheet
,throughout , they would be less coloured or less transmissive for the
same
colour intensity?


If the colour came off, it wasn't really a proper theatrical colour
filter. The name gel stems back to a time when colour was made from a
coloured gelatin based liquid poured out into a flat tray and left to
set. they were thick and unstable, prone to fading, shattering and
catching fire.

Later on, filters (theatrical types just call it colour) were made from
an acetate material which didn't handle the heat very well, This was
known as Cinemoid, also prone to fading and melting.
These days, proper theatrical colour filters are made with a very
complex process involving two or more layers of polyester and
polycarbonate. They still burn out, specially blue! Darker greens
wrinkle up for some some reason.


There is some very interesting reading on the Rosco and the Lee Filters
websites

Ron

These came from a set of gels (as they called them) for theatrical
floodlights, that I salvaged for the coloured material , when they got
replaced with a whole new range of lights. Nothing wrong with them , not
even crinkled. Seem to be a clear plastic core with a coating of couloured
something , each side, that easily dissolves off with meths, which I did not
expect.

 

[Dave Plowman (News)]

In article <hl0m2q$4jg$1@news.eternal-september.org>,
N_Cook <diverse@tcp.co.uk> wrote:

Went to clean a gel and the gel came off leaving clear celluloid or
whatever substrate.

Trying to dye varnish with red ink or dye only gave pink when applied to
a lens, with white shining through. Some floodlamp gel gave a proper red
colour. Is ther a general priciple here that if gels were dyed clear
sheet ,throughout , they would be less coloured or less transmissive for
the same colour intensity?

Only ones I see are distributed by Lee Electrics in the UK - for film and
TV, etc use. They are coloured throughout.

--
*No word in the English language rhymes with month, orange, silver,purple

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.