safelight -- 'Lamp Dip' Rosco's Colorine

"Nicholas O. Lindan" wrote in message
ink.net...
"Lloyd Erlick" Lloyd at @the-wire. dot com wrote

Small safelight bulbs under my cabinets and
in the far corners and down the passage to my
print washer would be very nice. I'd also
like a bit of light around my feet wherever
I'd have to walk, and to help find things
that get dropped. Christmas tree bulbs are
all over the place right now, and soon they
will be getting sold off cheap by the
retailers. They don't have such a long
lifespan, but if dipping them is cheap it
should be OK.

Lamp life can be quadrupled with the little
'energy saver' discs they sell for screw-in
lightbulbs. They are just a 1/2 wave rectifier
so the lamp runs on ~1/2 the voltage.
I don't know if anyone makes a 'plug-in' version
for Xmas tree lights, probably not as you
can start a fire by plugging a transformer
or squirrel cage motor into rectified/dc current.


My safelights get left on overnight/week/month
and burn out. I use 7 1/2 watt bulbs in Kodak
bullet safelights. I have been meaning to try ~15
watt bulbs and the discs - not to 'save' energy
but just to not run out of bulbs so fast.

BTW: the 'energy saver' discs waste energy:
they decrease the amount of light
more than they extend the life of the bulb.
I would recommend a lower wattage bulb if that's all
that's needed.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
To reply, remove spaces: n o lindan at ix . netcom . com
Fstop timer - http://www.nolindan.com/da/fstop/index.htm

Why not just use a dimmer switch for the safelight circuit? Or just wire a
small diode in one side of the AC line cord or plug?

(BTW, I respectfully (and cautiously, considering your sig line!) take
exception with your last 'graph-- "waste energy". Assume that you have two
7.5W bulbs, each with a diode in line. One bulb is lit on the positive side
of the sine wave, the other on the negative side. The two bulbs combined use
the entire sine wave and put out a total of 15 W. Each bulb is only putting
out half the heat as it would at full power, so the filaments should last
longer. )

--
Ken Hart

In article , Ken Hart wrote:
(BTW, I respectfully (and cautiously, considering your sig line!) take
exception with your last 'graph-- "waste energy". Assume that you have two
7.5W bulbs, each with a diode in line. One bulb is lit on the positive side
of the sine wave, the other on the negative side. The two bulbs combined use
the entire sine wave and put out a total of 15 W. Each bulb is only putting
out half the heat as it would at full power, so the filaments should last
longer. )

No they don't quite work that way. Incandesent bulbs put out 90% heat,
10% light at normal operating temperatures. At high temps, they are
brighter, bluer and last a lot less time.

If you remember the the 3400k Photoflood bulbs of yesteryear, they
only lasted about 4 hours. It wasn't because the bulbs were designed
to burn out quickly, it was because those extra 200k cost a lot in
filament life.

Running a lamp on a dimmer, or using a diode extends filament life because
it runs cooler, which makes it redder and the light to heat ratio,
or efficency as you would call it drops significantly.

Geoff.


--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838
You should have boycotted Google while you could, now Google supported
BPL is in action. Time is running out on worldwide radio communication.

"Ken Hart" wrote

(BTW, I respectfully (and cautiously, considering your sig line!) take
exception with your last 'graph-- "waste energy". Assume that you have two
7.5W bulbs, each with a diode in line. One bulb is lit on the positive side
of the sine wave, the other on the negative side. The two bulbs combined use
the entire sine wave and put out a total of 15 W. Each bulb is only putting
out half the heat as it would at full power,

Lightbulbs aren't linear beasts. There are a few websites with the
math for voltage Vs energy consumed Vs light output Vs filament life.
As voltage drops the lamp efficiency goes down the loo.

Plain old grocery store lamps - not the long life variety - are the
most efficient compromise between light output/energy cost/bulb cost.

By wasting a bit of energy you can increase lamp life. Long life
bulbs in the USA are made to run on 130V rather than the 115V they
are plugged into - that's all there is to it.

From the web site:

http://www.gilway.com/html/appl-tungsten.html

A half-wave rectifier provides ~70% of the RMS [Root Mean Square -
sqrt(integral (V^2) dt)] voltage - the value used when AC voltages
and currents are talked about. The charts only go to 80% voltage,
but what the hey, at 80%:

Current is 89% of nominal, voltage is 80% = power is 70% lower
Light output is 35% of nominal
Light color goes from white to orange, where the eye is less sensitive

Using an 'energy saver' the efficiency went down by 50%: 0.35 the light
for 0.70 the power. You are better off using a lightbulb of 1/3 the
wattage and getting decent white light out of it.

so the filaments should last longer.

That they will, about 20x longer.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
To reply, remove spaces: n o lindan at ix . netcom . com
Fstop timer - http://www.nolindan.com/da/fstop/index.htm

Lloyd Erlick wrote:

wrote:

Were it not for your being so wedded to MG there would be a
welcoming well lite darkroom at your disposal. Have you ever
given orangeish yellow a try? Dan

November 9, 2005, from Lloyd Erlick,,

Well, that's a good point.

Ilford has proclaimed a mighty press release;
they plan to be the last ones standing in
back and white. So does that mean I can work
with Galerie graded FB paper and have some
prospect of being able to get it for a while?

Sounds like a different thread, though ...
________________________________
Lloyd Erlick Portraits, Toronto.
voice: 416-686-0326
email:
net: www.heylloyd.com


A different thread? Only if Rosco has no orangeish yellow.
Galerie is one of many Graded papers, FB and RC. There are
a few papers offered in only one grade. One grade of paper I'd
think would do for you as I expect your exposure and
processing are well under control.
Besides, that Ansco 120 is Beer's A save for dilution. Add Beer's
B for MG. Also, Ansel's Ansco 130 is an A and B MG developer. Dan

Buy the correct safelight and filter.

Don't be so ****ing cheap.

Lloyd Erlick wrote:
November 7, 2005, from Lloyd Erlick,,

I've been poking about making my darkroom
functional again, and the topic of safelights
has intruded upon my mind. Here is a web page
I found that might be of interest:

(I haven't tried this, so I can't say if one
of the red lamp dips is actually safe for
photo materials. Maybe someone on the
darkroom list is familiar with this product.)
...

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~
http://wolfstone.halloweenhost.com/T...t.html#LampDip


Lamp Dip
Lamp dip is a paint-like liquid specially
designed to be applied to a lamp by painting
on the glass envelope, or dipping the bulb
into the liquid. This leaves a film on the
lamp that colors the light.

Lamp dip is designed to work in hot
environments like the surface of a lamp, but
it has limitations, and will burn off
extremely hot lamps. Check the manufacturer's
specifications to find the limitations of the
product.

There are probably several outfits that make
stuff like this, but the most famous is
Rosco's Colorine, which was the first product
that the company made, back in 1910. Colors
are described as "brilliant and long
lasting", but "not for permanent
installations." Another reference suggests
Colorine for use on incandescent lamps of 40W
or less.

part number
color
Roscolux filter equivalent

07601
Cardinal Red
26

07602
Ruby Red
27

07603
Magenta
49

...

Colorine is only available in pints. It costs
a little over $14/pint as of January 2004.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

regards,
--le
________________________________
Lloyd Erlick Portraits, Toronto.
voice: 416-686-0326
email:
net: www.heylloyd.com
________________________________
--

UC spake thus:

Buy the correct safelight and filter.
Don't be so ****ing cheap.

What are you, made out of money?

Oh, yeah, that's right, you're a Republican.


--
.... asked to comment on Michigan governor George Romney's remark that
the army had "brainwashed" him in Vietnam—-a remark which knocked Romney
out of the running for the Republican nomination—-McCarthy quipped,
"I think in that case a light rinse would have been sufficient."

(Eugene McCarthy, onetime candidate for POTUS)

A good safelight is a necessity. If you cannot afford one, why are you
even doing darkroom work? Used safelights are cheaper, if you need to
get one cheaply.


David Nebenzahl wrote:
UC spake thus:

Buy the correct safelight and filter.
Don't be so ****ing cheap.

What are you, made out of money?

Oh, yeah, that's right, you're a Republican.


--
... asked to comment on Michigan governor George Romney's remark that
the army had "brainwashed" him in Vietnam--a remark which knocked Romney
out of the running for the Republican nomination--McCarthy quipped,
"I think in that case a light rinse would have been sufficient."

(Eugene McCarthy, onetime candidate for POTUS)