Infrared light leak

Last night I was developing some sheet film in my darkroom. I'm always on
the alert for "light leaks," because the darkroom is a converted bedroom. I
kept getting the annoying feeling that some light was leaking in from around
the main door. But whenever I looked directly at the door, I couldn't
pinpoint any leaks. It bugged me.

Today I fished-out my infrared night vision monocular, figuring that since
it amplifies available light tens of thousands of times, it would reveal any
leaks, no matter how small. I panned around the room, and when I came to
the door, I stopped in amazement. What I saw looked like an x-ray of the
door! I could clearly make out the rectangular outline, and several thin,
horizontal opaque strips, along with one large opaque rectangle around the
doorknob. What I was seeing was infrared light penetrating the veneer of
the door, as well as the horizontal re-enforcement strips of solid pine, and
the re-enforcement plate around the doorknob!

So, in addition to plastic body cameras, I guess we need to be aware that
some "solid" doors aren't!

My solution was simple: I painted both sides of the door in flat black
paint. The pigment in the paint *is* IR-opaque.

-- Theo Benson, Grizzly Glen Photography
www.chameleon.net/ursus

Infrared night vision monocular indeed!The first time I saw such a thing was
in the army.I hope I will never, ever need to use one, because that would
mean a war.

--
Dimitris Tzortzakakis,Iraklion Crete,Greece
Analogue technology rules-digital sucks
http://www.patriko-kreta.com
dimtzort AT otenet DOT gr the return adress is corrupted
Warning:all offending emails will be deleted, and the offender/spammer
will be put on my personal "black list".
Ï "Ursus Californicus" Ýãñáøå óôï ìÞíõìá
hlink.net...
Last night I was developing some sheet film in my darkroom. I'm always on
the alert for "light leaks," because the darkroom is a converted bedroom.
I
kept getting the annoying feeling that some light was leaking in from
around
the main door. But whenever I looked directly at the door, I couldn't
pinpoint any leaks. It bugged me.

Today I fished-out my infrared night vision monocular, figuring that since
it amplifies available light tens of thousands of times, it would reveal
any
leaks, no matter how small. I panned around the room, and when I came to
the door, I stopped in amazement. What I saw looked like an x-ray of the
door! I could clearly make out the rectangular outline, and several thin,
horizontal opaque strips, along with one large opaque rectangle around the
doorknob. What I was seeing was infrared light penetrating the veneer of
the door, as well as the horizontal re-enforcement strips of solid pine,
and
the re-enforcement plate around the doorknob!

So, in addition to plastic body cameras, I guess we need to be aware that
some "solid" doors aren't!

My solution was simple: I painted both sides of the door in flat black
paint. The pigment in the paint *is* IR-opaque.

-- Theo Benson, Grizzly Glen Photography
www.chameleon.net/ursus

Now being used by sports enthusiasts everywhere, and have been used in
commercial darkrooms for years to load film and recover films dropped on the
floor during the loading process. Kodak even makes an IR filter for their
safelite housing.

--
darkroommike

----------
"Tzortzakakis Dimitrios" wrote in
message ...
Infrared night vision monocular indeed!The first time I saw such a thing
was
in the army.I hope I will never, ever need to use one, because that would
mean a war.

--
Dimitris Tzortzakakis,Iraklion Crete,Greece
Analogue technology rules-digital sucks
http://www.patriko-kreta.com
dimtzort AT otenet DOT gr the return adress is corrupted
Warning:all offending emails will be deleted, and the offender/spammer
will be put on my personal "black list".
Ï "Ursus Californicus" Ýãñáøå óôï ìÞíõìá
hlink.net...
Last night I was developing some sheet film in my darkroom. I'm always
on
the alert for "light leaks," because the darkroom is a converted
bedroom.
I
kept getting the annoying feeling that some light was leaking in from
around
the main door. But whenever I looked directly at the door, I couldn't
pinpoint any leaks. It bugged me.

Today I fished-out my infrared night vision monocular, figuring that
since
it amplifies available light tens of thousands of times, it would reveal
any
leaks, no matter how small. I panned around the room, and when I came
to
the door, I stopped in amazement. What I saw looked like an x-ray of
the
door! I could clearly make out the rectangular outline, and several
thin,
horizontal opaque strips, along with one large opaque rectangle around
the
doorknob. What I was seeing was infrared light penetrating the veneer
of
the door, as well as the horizontal re-enforcement strips of solid pine,
and
the re-enforcement plate around the doorknob!

So, in addition to plastic body cameras, I guess we need to be aware
that
some "solid" doors aren't!

My solution was simple: I painted both sides of the door in flat black
paint. The pigment in the paint *is* IR-opaque.

-- Theo Benson, Grizzly Glen Photography
www.chameleon.net/ursus

And this is a good point to remember if you shoot EIR (Kodak's false-color
IR slide film): make sure the lab does NOT use darkened rooms and IR
goggles for the technicians running the processors. Many labs do, and it
can kill your film. My old lab held the IR stuff for the last run of the
day, and the technician simply turned his goggles off before loading the
machine.

-- Theo

I think there are automated processing machines that use infrared light to
sense the position of the film. EIR comes back uniformly deep red when this
is done.

One lab that can do it correctly is www.colorchrome.com.

"Ursus Californicus" wrote in message
link.net...
And this is a good point to remember if you shoot EIR (Kodak's false-color
IR slide film): make sure the lab does NOT use darkened rooms and IR
goggles for the technicians running the processors. Many labs do, and it
can kill your film. My old lab held the IR stuff for the last run of the
day, and the technician simply turned his goggles off before loading the
machine.

-- Theo

Yes, some of the processors (I think mainly the older ones) use IR film
position sensors, and they will obliterate EIR. I make it a point to ask
for the manager if I'm using a new lab, and ask about their machines before
leaving my film.

Oh -- and I put packing tape across the film capsule and write "IR - do NOT
open in light!" on it. This is because I once took a roll of EIR into a
"pro" lab, and even as I was warning the counter guy not to open the
capsule, he opened it. Fortunately, I screamed loudly enough, and his
reaction time was good enough, that he slammed the cap back on, I only lost
four images, and I got the processing and a new roll for free. }:xD

-- Theo Benson
Grizzly Glen Photography
www.chameleon.net/ursus

All the EIR i've ever shot has been hand processed. Not sure if I've
ever even known any labs that walk around with ir goggles. And if
they do so when developing IR film then they shouldn't be developing
my film anyway


On Sun, 13 Jun 2004 15:01:53 GMT, "Ursus Californicus"
wrote:

And this is a good point to remember if you shoot EIR (Kodak's false-color
IR slide film): make sure the lab does NOT use darkened rooms and IR
goggles for the technicians running the processors. Many labs do, and it
can kill your film. My old lab held the IR stuff for the last run of the
day, and the technician simply turned his goggles off before loading the
machine.

-- Theo


Cheers,
-sd
http://www.zoom.sh

Maybe I don't get it but...If you take risky film to a lab and they do
exactly the opposite of what you tell them, destroy four of your
images (which could have been the 4 you wanted), and then offer a free
roll and processing, I think I'd probably ask them for cash money and
never come back again.

Another thing I don't get is the EIR film and the "capsule". If
you're talking about the film cannister that the EIR comes in, i'm not
sure why opening that would expose any of the images in the roll
unless the actual film container was broken. I've shot dozens of
rolls of EIR and developed them without any fogging/destruction
regardless if the roll was protected by its original cannister...





On Sun, 13 Jun 2004 17:14:40 GMT, "Ursus Californicus"
wrote:

Yes, some of the processors (I think mainly the older ones) use IR film
position sensors, and they will obliterate EIR. I make it a point to ask
for the manager if I'm using a new lab, and ask about their machines before
leaving my film.

Oh -- and I put packing tape across the film capsule and write "IR - do NOT
open in light!" on it. This is because I once took a roll of EIR into a
"pro" lab, and even as I was warning the counter guy not to open the
capsule, he opened it. Fortunately, I screamed loudly enough, and his
reaction time was good enough, that he slammed the cap back on, I only lost
four images, and I got the processing and a new roll for free. }:xD

-- Theo Benson
Grizzly Glen Photography
www.chameleon.net/ursus


Cheers,
-sd
http://www.zoom.sh

"Some Dude" wrote in message
...
Maybe I don't get it but...If you take risky film to a lab and they do
exactly the opposite of what you tell them, destroy four of your
images (which could have been the 4 you wanted), and then offer a free
roll and processing, I think I'd probably ask them for cash money and
never come back again.

Another thing I don't get is the EIR film and the "capsule". If
you're talking about the film cannister that the EIR comes in, i'm not
sure why opening that would expose any of the images in the roll
unless the actual film container was broken. I've shot dozens of
rolls of EIR and developed them without any fogging/destruction
regardless if the roll was protected by its original cannister...

I, too, have handled EIR cassettes in ordinary room light several times
without any fogging.

Nothing extreme like direct sunlight, of course -- but no problems indoors.

Kodak's black and white infrared is coated onto a thin "Estar" (polyester?)
base material and is notorious for "light piping"--the room light follows
the leader into the cassette and fogs the film, additionally the Kodak felt
on the cassette lips is not very IR tight either. But the color film is on
a standard acetate base and does not have the same special problems as the
black and white stuff.

--
darkroommike

----------
"Michael A. Covington" wrote
in message news

"Some Dude" wrote in message
...
Maybe I don't get it but...If you take risky film to a lab and they do
exactly the opposite of what you tell them, destroy four of your
images (which could have been the 4 you wanted), and then offer a free
roll and processing, I think I'd probably ask them for cash money and
never come back again.

Another thing I don't get is the EIR film and the "capsule". If
you're talking about the film cannister that the EIR comes in, i'm not
sure why opening that would expose any of the images in the roll
unless the actual film container was broken. I've shot dozens of
rolls of EIR and developed them without any fogging/destruction
regardless if the roll was protected by its original cannister...

I, too, have handled EIR cassettes in ordinary room light several times
without any fogging.

Nothing extreme like direct sunlight, of course -- but no problems
indoors.