WATTS - Hot light, Cold Light

Briefly: For strictly black & white printing, does a cold head gives as
much _usable_ light as, say, four 150W tungsten bulbs? Four 250W bulbs?
Do the cold lights give more effective light per-watt?

You see, I was given that might (might) be suitable for a light head for
the Saltzman 8x10" enlarger. Maybe. It is steel, uses four Edison base
bulbs with wiring sufficient to accommodate four 250W bulbs. It has four
150 bulbs now. (GE brand with the printing on the side of the bulbs.)
The bulbs are on the sides of the box, in reflectors and shielded from
direct view of the negative carrier. And there are two fans in it and
it's light proof vented, and it has a large, thick, heatproof glass over
the open part. I do not think it was ever an enlarging head. For good
reason, I'll bet.

(If it is important I can make a snapshot to post to my web site.)

Thank you, all.
--
JJS in MinneSnowta

"John J" wrote in message
m...
Briefly: For strictly black & white printing, does a cold
head gives as much _usable_ light as, say, four 150W
tungsten bulbs? Four 250W bulbs? Do the cold lights give
more effective light per-watt?

You see, I was given that might (might) be suitable for a
light head for the Saltzman 8x10" enlarger. Maybe. It is
steel, uses four Edison base bulbs with wiring sufficient
to accommodate four 250W bulbs. It has four 150 bulbs now.
(GE brand with the printing on the side of the bulbs.) The
bulbs are on the sides of the box, in reflectors and
shielded from direct view of the negative carrier. And
there are two fans in it and it's light proof vented, and
it has a large, thick, heatproof glass over the open part.
I do not think it was ever an enlarging head. For good
reason, I'll bet.

(If it is important I can make a snapshot to post to my
web site.)

Thank you, all.
--
JJS in MinneSnowta

I'm not sure what you have but it might have been an
illuminator of some sort. There were lamphouses along those
lines used on enlargers.
In general flourescent lamps, including the compact
type, produce quite a bit more light per watt than
incandescent lamps. I don't think there is a definite ratio
but I would say about four times the light. For use on an
enlarger using variable contrast paper the phosphor color
needs to be selected so that the filters will work. Normal
"cold light" enlarger lamps were pretty blue and require a
yellow filter to get any sort of range and then its
compressed. I think the warm-white compact lamps that look
like tungsten may work pretty well but you will have to try
them and the filters will probably not have quite the same
contrast or spacing that they do with a tungsten lamp. The
compact flourescents will dissipate a fraction of the heat
of a tungsten lamp with similar light output. You can get
compact lamps with light output equal to at least a 200 watt
tungsten lamp at many stores but I don't know if they come
in all colors.
For graded paper the blue lamps work fine.


--
--
Richard Knoppow
Los Angeles, CA, USA

If you have a range of contrast grades to print, incandescent are the
best choice IMOP. Cold light is fine if your negatives fall within the
normal to more contrasty range. Most papers are spectrally suited and
formulated to work better with incandescent.


In article ,
John J wrote:

Briefly: For strictly black & white printing, does a cold head gives as
much _usable_ light as, say, four 150W tungsten bulbs? Four 250W bulbs?
Do the cold lights give more effective light per-watt?

You see, I was given that might (might) be suitable for a light head for
the Saltzman 8x10" enlarger. Maybe. It is steel, uses four Edison base
bulbs with wiring sufficient to accommodate four 250W bulbs. It has four
150 bulbs now. (GE brand with the printing on the side of the bulbs.)
The bulbs are on the sides of the box, in reflectors and shielded from
direct view of the negative carrier. And there are two fans in it and
it's light proof vented, and it has a large, thick, heatproof glass over
the open part. I do not think it was ever an enlarging head. For good
reason, I'll bet.

(If it is important I can make a snapshot to post to my web site.)

Thank you, all.
--
JJS in MinneSnowta

--
Reality is a picture perfected and never looking back.

Richard Knoppow wrote:
"John J" wrote in message
m...
Briefly: For strictly black & white printing, does a cold
head gives as much _usable_ light as, say, four 150W
tungsten bulbs? Four 250W bulbs? Do the cold lights give
more effective light per-watt?

You see, I was given that might (might) be suitable for a
light head for the Saltzman 8x10" enlarger. Maybe. It is
steel, uses four Edison base bulbs with wiring sufficient
to accommodate four 250W bulbs. It has four 150 bulbs now.
(GE brand with the printing on the side of the bulbs.) The
bulbs are on the sides of the box, in reflectors and
shielded from direct view of the negative carrier. And
there are two fans in it and it's light proof vented, and
it has a large, thick, heatproof glass over the open part.
I do not think it was ever an enlarging head. For good
reason, I'll bet.

(If it is important I can make a snapshot to post to my
web site.)

Thank you, all.
--
JJS in MinneSnowta

I'm not sure what you have but it might have been an
illuminator of some sort. There were lamphouses along those
lines used on enlargers.
In general flourescent lamps, including the compact
type, produce quite a bit more light per watt than
incandescent lamps. I don't think there is a definite ratio
but I would say about four times the light. For use on an
enlarger using variable contrast paper the phosphor color
needs to be selected so that the filters will work. Normal
"cold light" enlarger lamps were pretty blue and require a
yellow filter to get any sort of range and then its
compressed. I think the warm-white compact lamps that look
like tungsten may work pretty well but you will have to try
them and the filters will probably not have quite the same
contrast or spacing that they do with a tungsten lamp. The
compact flourescents will dissipate a fraction of the heat
of a tungsten lamp with similar light output. You can get
compact lamps with light output equal to at least a 200 watt
tungsten lamp at many stores but I don't know if they come
in all colors.
For graded paper the blue lamps work fine.

Thanks, Richard. I think you are talking about the bulbs available to
replace ordinary tungsten Edison based bulbs. If that's the case, then I
will go to the home supply place today and get a couple and first try
them in the Focomat Ia! What better way to test without spending a lot?
If the bulbs are not suitable, I'll put them in the workshop.

Rise-time concerns me, but I'll find out!

JJS

____ wrote:
If you have a range of contrast grades to print, incandescent are the
best choice IMOP. Cold light is fine if your negatives fall within the
normal to more contrasty range. Most papers are spectrally suited and
formulated to work better with incandescent.

Oh. Darn. I must confess that in forty years I have never chosen
subjects to suit a processing regime. I'm not Zone obsessive. All I use
is a simple N-+ exposure and development method. It would be different
if I were a studio photographer.

So having an ideal negative is really unlikely for me.

Said without disrespect to Zone Masters.

JJS

"John J" wrote in message
m...
Richard Knoppow wrote:
"John J" wrote in message
m...
Briefly: For strictly black & white printing, does a
cold head gives as much _usable_ light as, say, four
150W tungsten bulbs? Four 250W bulbs? Do the cold lights
give more effective light per-watt?

You see, I was given that might (might) be suitable for
a light head for the Saltzman 8x10" enlarger. Maybe. It
is steel, uses four Edison base bulbs with wiring
sufficient to accommodate four 250W bulbs. It has four
150 bulbs now. (GE brand with the printing on the side
of the bulbs.) The bulbs are on the sides of the box, in
reflectors and shielded from direct view of the negative
carrier. And there are two fans in it and it's light
proof vented, and it has a large, thick, heatproof glass
over the open part. I do not think it was ever an
enlarging head. For good reason, I'll bet.

(If it is important I can make a snapshot to post to my
web site.)

Thank you, all.
--
JJS in MinneSnowta

I'm not sure what you have but it might have been an
illuminator of some sort. There were lamphouses along
those lines used on enlargers.
In general flourescent lamps, including the compact
type, produce quite a bit more light per watt than
incandescent lamps. I don't think there is a definite
ratio but I would say about four times the light. For use
on an enlarger using variable contrast paper the phosphor
color needs to be selected so that the filters will work.
Normal "cold light" enlarger lamps were pretty blue and
require a yellow filter to get any sort of range and then
its compressed. I think the warm-white compact lamps that
look like tungsten may work pretty well but you will have
to try them and the filters will probably not have quite
the same contrast or spacing that they do with a tungsten
lamp. The compact flourescents will dissipate a fraction
of the heat of a tungsten lamp with similar light output.
You can get compact lamps with light output equal to at
least a 200 watt tungsten lamp at many stores but I don't
know if they come in all colors.
For graded paper the blue lamps work fine.

Thanks, Richard. I think you are talking about the bulbs
available to replace ordinary tungsten Edison based bulbs.
If that's the case, then I will go to the home supply
place today and get a couple and first try them in the
Focomat Ia! What better way to test without spending a
lot? If the bulbs are not suitable, I'll put them in the
workshop.

Rise-time concerns me, but I'll find out!

JJS

One problem with any gaseous discharge lamp, which
includes all fluorescent lamps, is that the output varies
with temperature. The lamps like to run hot and in an
enlarger should preferably be run continuously. The original
lamp house used in the Saltzman employed mercury vapor
tubular lamps which were run continuously so that exposure
was controlled by a shutter similar to the Packard shutter
which was held in front of the lens on a fixture. A shutter
also give precise control of exposure, large tungsten lamps
have a lag on turning on and take a short time to fade out.
Not a problem for the small wattage lamps found in most
enlargers. The compact fluorescent lamps are cheap enough to
allow testing plus if they don't work you can use them
around the house.


--
--
Richard Knoppow
Los Angeles, CA, USA

Richard Knoppow wrote:

One problem with any gaseous discharge lamp, which
includes all fluorescent lamps, is that the output varies
with temperature. The lamps like to run hot and in an
enlarger should preferably be run continuously. The original
lamp house used in the Saltzman employed mercury vapor
tubular lamps which were run continuously so that exposure
was controlled by a shutter similar to the Packard shutter
which was held in front of the lens on a fixture. A shutter
also give precise control of exposure, large tungsten lamps
have a lag on turning on and take a short time to fade out.
Not a problem for the small wattage lamps found in most
enlargers. The compact fluorescent lamps are cheap enough to
allow testing plus if they don't work you can use them
around the house.

Excellent points. We discussed the lens shutter earlier. I had modified
an electric long-roll camera shutter to use on the Saltzman, but learned
that it was not proper to use with my favorite timer, the F-Stop timer
from Darkroom Automation. The essential issue there was that the
electric shutter was really intended for faster shutter speeds than
needed with enlarging. There were components to close it, a capacitor,
and other things. Don't need that here.

I have plenty of experience with Packards. I use one for very large lenses.

For some reason I thoughtlessly disregarded the Packard solution for
enlarging. It will work perfectly with the F-Stop and any other
conventional timer. I'll actuate the Packard electrically with a simple,
low-overhead DC electric piston or solenoid. I've done the later.

Happy day. It is about to rain so I'll spend the afternoon with a spare
Packard and the Saltzman head.

Thank you, Richard

JJS

John J wrote:
Briefly: For strictly black & white printing, does a cold head gives as
much _usable_ light as, say, four 150W tungsten bulbs? Four 250W bulbs?
Do the cold lights give more effective light per-watt?

You see, I was given that might (might) be suitable for a light head for
the Saltzman 8x10" enlarger. Maybe. It is steel, uses four Edison base
bulbs with wiring sufficient to accommodate four 250W bulbs. It has four
150 bulbs now. (GE brand with the printing on the side of the bulbs.)
The bulbs are on the sides of the box, in reflectors and shielded from
direct view of the negative carrier. And there are two fans in it and
it's light proof vented, and it has a large, thick, heatproof glass over
the open part. I do not think it was ever an enlarging head. For good
reason, I'll bet.

(If it is important I can make a snapshot to post to my web site.)

Thank you, all.
--
JJS in MinneSnowta


John,
my .02, for my enlargers (yet to be completed, due to lack of anywhere to put them) I'm
making a cold light head, basically 10-15mm neon tube, bent in a serpentine manner, quite
a bit larger than need be, 2 pieces of thin white acrylic and I will have a light source
that won't buckle negatives, and should give me decent exposure times. Basically a Aristo
head, Voltarc, the company that makes Aristo, happens to be a supplier to the neon
industry as well (no surprise, huh?

Properly processed neon tubes are bright as all get out, and using a Packard type
shutter(from a graphic arts camera, with a 110v solenoid)I can leave the tubes on
continuously, heck, maybe I'll add a few resistors in the cabinet to keep the lamp house
at a constant temperature as well.


erie

erie patsellis wrote:

John,
my .02, for my enlargers (yet to be completed, due to lack of anywhere
to put them) I'm making a cold light head, basically 10-15mm neon tube,
bent in a serpentine manner, quite a bit larger than need be, 2 pieces
of thin white acrylic and I will have a light source that won't buckle
negatives, and should give me decent exposure times. Basically a Aristo
head, Voltarc, the company that makes Aristo, happens to be a supplier
to the neon industry as well (no surprise, huh?

There is still the issue of the Kelvin temp of the light. No?

Properly processed neon tubes are bright as all get out, and using a
Packard type shutter(from a graphic arts camera, with a 110v solenoid)I
can leave the tubes on continuously, heck, maybe I'll add a few
resistors in the cabinet to keep the lamp house at a constant
temperature as well.

Fer gosh sake, Erie, let's set up a studio and darkroom somewhere
between here and there, or maybe here. I am close to retirement.
Closer than I want to be.

John J wrote:
erie patsellis wrote:

John,
my .02, for my enlargers (yet to be completed, due to lack of anywhere
to put them) I'm making a cold light head, basically 10-15mm neon
tube, bent in a serpentine manner, quite a bit larger than need be, 2
pieces of thin white acrylic and I will have a light source that won't
buckle negatives, and should give me decent exposure times. Basically
a Aristo head, Voltarc, the company that makes Aristo, happens to be a
supplier to the neon industry as well (no surprise, huh?

There is still the issue of the Kelvin temp of the light. No?

Yes, and there are several neon tubes that get us in the 3000 to 3200 degree range, you
can also go with 2 tubes, one more towards the blue spectrum, one towards the green, for
those multigrade types.



Properly processed neon tubes are bright as all get out, and using a
Packard type shutter(from a graphic arts camera, with a 110v
solenoid)I can leave the tubes on continuously, heck, maybe I'll add a
few resistors in the cabinet to keep the lamp house at a constant
temperature as well.

Fer gosh sake, Erie, let's set up a studio and darkroom somewhere
between here and there, or maybe here. I am close to retirement.
Closer than I want to be.

If only the school had a good FA program, I might be tempted, the wife graduates this
year, and we were planning on moving to St. Louis, unless I find a better program that
will accept an old fart set in his ways, and just looking for "artistic" guidance, instead
of attempting to teach me aperture, shutter speeds, here's how you develop b&w film,
etc... fer chrissake, I probably process more b&w & C41 film in any month than most
college labs do in a year.