Black and White Astrophotography Question

I have been dabbling in color prime focus astrophotography for some
time now. I have never tried black and white, but I recently aquired
a photographic enlarger, and some film and paper development equipment
for black and white films. I have several questions about black and
white astrophotography.

1. I can't afford a lumicon hypering chamber and the gas for it. Is
there any alternative to this? In the hopes of somehow devising my
own setup, I've looked locally for a someone who can get
hydrogen/nitrogen mixture, but no one really wants to fool with it for
such a small amount.

2. I really dont want to hyper the film anyway, is there any kind of
black and white film I can use that doesn't need to be hypered? I
read in Micheal covington's book that tmax400 (or was it 100?) was ok
if you could not get hypered film. Would I need to select my targets
carefully? Also I can't find many pictures on the internet in black
and white with anything other than techpan.

Ok, now for the outlandish questions ...
3. Is there any other thing that black and white film can be treated
with that would make it better for astrophotography? Perhaps
something that would shift the "spectral sensitivity curve" slightly
toward the red?

And, the truly absurd ...
4. Is there anyway to change the color/wavelength of the light on the
way to the film, so that the film would respond better to it?

thanks for any help you can provide here. Anything at all ...

Ouch! Not even one response. Just curious, is it just a stupid
question and no one wants to bother with it, or is it that no one
knows the answer?

thanks,
Art

(Art) wrote in message . com...
I have been dabbling in color prime focus astrophotography for some
time now. I have never tried black and white, but I recently aquired
a photographic enlarger, and some film and paper development equipment
for black and white films. I have several questions about black and
white astrophotography.

1. I can't afford a lumicon hypering chamber and the gas for it. Is
there any alternative to this? In the hopes of somehow devising my
own setup, I've looked locally for a someone who can get
hydrogen/nitrogen mixture, but no one really wants to fool with it for
such a small amount.

2. I really dont want to hyper the film anyway, is there any kind of
black and white film I can use that doesn't need to be hypered? I
read in Micheal covington's book that tmax400 (or was it 100?) was ok
if you could not get hypered film. Would I need to select my targets
carefully? Also I can't find many pictures on the internet in black
and white with anything other than techpan.

Ok, now for the outlandish questions ...
3. Is there any other thing that black and white film can be treated
with that would make it better for astrophotography? Perhaps
something that would shift the "spectral sensitivity curve" slightly
toward the red?

And, the truly absurd ...
4. Is there anyway to change the color/wavelength of the light on the
way to the film, so that the film would respond better to it?

thanks for any help you can provide here. Anything at all ...

Hi Judge Vandelay,

There was an article in S&T maybe 15 years ago about hypering tech Pan
with a silver solution. This at the time was a preferred method of
hypering film for some French observatory (maybe Pic). The drawback
was that the film had to be used within a few hours of hypering.

Tech Pan is very red sensitive as is.

If interested I could dig out that issue.... if a google search on
your part using the terms "silver hyper tech," etc., doesn't work.


(Art) wrote in message . com...
I have been dabbling in color prime focus astrophotography for some
time now. I have never tried black and white, but I recently aquired
a photographic enlarger, and some film and paper development equipment
for black and white films. I have several questions about black and
white astrophotography.

1. I can't afford a lumicon hypering chamber and the gas for it. Is
there any alternative to this? In the hopes of somehow devising my
own setup, I've looked locally for a someone who can get
hydrogen/nitrogen mixture, but no one really wants to fool with it for
such a small amount.

2. I really dont want to hyper the film anyway, is there any kind of
black and white film I can use that doesn't need to be hypered? I
read in Micheal covington's book that tmax400 (or was it 100?) was ok
if you could not get hypered film. Would I need to select my targets
carefully? Also I can't find many pictures on the internet in black
and white with anything other than techpan.

Ok, now for the outlandish questions ...
3. Is there any other thing that black and white film can be treated
with that would make it better for astrophotography? Perhaps
something that would shift the "spectral sensitivity curve" slightly
toward the red?

And, the truly absurd ...
4. Is there anyway to change the color/wavelength of the light on the
way to the film, so that the film would respond better to it?

thanks for any help you can provide here. Anything at all ...

On 29 Jul 2003 13:15:10 -0700, (Art) wrote:

I have been dabbling in color prime focus astrophotography for some
time now. I have never tried black and white, but I recently aquired
a photographic enlarger, and some film and paper development equipment
for black and white films. I have several questions about black and
white astrophotography.

1. I can't afford a lumicon hypering chamber and the gas for it. Is
there any alternative to this? In the hopes of somehow devising my
own setup, I've looked locally for a someone who can get
hydrogen/nitrogen mixture, but no one really wants to fool with it for
such a small amount.

There is another way to hyper a film: just give it some light to start!
The technique is touchy: you need to expose the film to some light
just enough so that it barely begins to darken. The reason for this
is called "hysteresis", the silver grains needs a few photons before
they begin to react... The problem: you only have a few hours after
to take your pictures AND to develop the film.

2. I really dont want to hyper the film anyway, is there any kind of
black and white film I can use that doesn't need to be hypered? I
read in Micheal covington's book that tmax400 (or was it 100?) was ok
if you could not get hypered film. Would I need to select my targets
carefully? Also I can't find many pictures on the internet in black
and white with anything other than techpan.

TechPan is a very high contrast, very fine grain scientific film. I have seen
very good results, some of them better than Techpan with TMax400. I
suggest that you try too Ilford Delta 400, Delta 3200 ( this one may be too
grainy) and the superb XP2 400. The XP2 is a very fine grain, very very wide
dynamic range BW film that must be developped in C41 (color) chemical.
More info at http://www.ilford.com/html/us_english/bw.html


Ok, now for the outlandish questions ...
3. Is there any other thing that black and white film can be treated
with that would make it better for astrophotography? Perhaps
something that would shift the "spectral sensitivity curve" slightly
toward the red?
Most silver halides used today are not sensitive to red light so the
manufacturers have to use chemical tricks to do exactly what you are describing
here. There are two kinds of BW film on the market today: OrthoChromatic ones,
sensitive only to green and blue and PanChromatic ones. Why do you think they
always use the word PAN in the name of many films?!?! It was quite
a fabulous shock when Kodak got the first Panchromatic film in the
30's. Remember the funny make-up for the actors of the old movies?

BTW, BW papers are not treated that way so that we can develop them
with a red safety light.


And, the truly absurd ...
4. Is there anyway to change the color/wavelength of the light on the
way to the film, so that the film would respond better to it?


It is not absurd because there exist a physical process by wich we can change
the wavelength of light. It is called the "Doppler red shift". Suppose
you want to take a picture of a very old globular cluster. Because it is old,
most of its stars are reddish. So we want to shift the wavelength toward the
blue end of the spectrum.

All you have to do is to fly AWAY from the cluster while taking your picture.
You can begin with a speed of about 100 000 kM/s ( a third of the speed of
light) to see if it shift enough for you. You then accelerate or deccelerate
to get a good color balance...

thanks for any help you can provide here. Anything at all ...

A
From: (Art)
A
Subject: Black and White Astrophotography Question
A
Date: 31 Jul 2003 09:02:43 -0700
A
Organization: http://groups.google.com/
A
A Ouch! Not even one response. Just curious, is it just a stupid
A question and no one wants to bother with it, or is it that no one
A knows the answer?
A
A I have been dabbling in color prime focus astrophotography for some
A time now. I have never tried black and white, but I recently aquired
A a photographic enlarger, and some film and paper development equipment
A for black and white films. I have several questions about black and
A white astrophotography.
A
A 1. I can't afford a lumicon hypering chamber and the gas for it. Is
A there any alternative to this? In the hopes of somehow devising my
A own setup, I've looked locally for a someone who can get
A hydrogen/nitrogen mixture, but no one really wants to fool with it for
A such a small amount.

I personally never knew any one who actually had the Lumicon (or
other) hypering kit. It just seemed too fiddly and perhaps dangerous.
Now that Lumicon is revived, maybe the kit is at sale again.

A 2. I really dont want to hyper the film anyway, is there any kind of
A black and white film I can use that doesn't need to be hypered? I
A read in Micheal covington's book that tmax400 (or was it 100?) was ok
A if you could not get hypered film. Would I need to select my targets
A carefully? Also I can't find many pictures on the internet in black
A and white with anything other than techpan.

An old but effective metod of sensitizing B&W film was cooling.
Put the film in the bottom bin of the refrigerator (away from the
chilling coils and definitely NOT in the freezer bin). This keeps the
film constant at around 10C. For einter photography, we would leave
the film outdoors (on the outside of a window sill, for instance) for
a while before using it that night. In this case, there is the caution
to advance the film very slowly to prevent static and snapping.

A Ok, now for the outlandish questions ...
A 3. Is there any other thing that black and white film can be treated
A with that would make it better for astrophotography? Perhaps
A something that would shift the "spectral sensitivity curve" slightly
A toward the red?

You can't 'shift the spectral response of the film without some
very cunning chemistry. Just develop the fi, for constrast.

A And, the truly absurd ...
A 4. Is there anyway to change the color/wavelength of the light on the
A way to the film, so that the film would respond better to it?

`No. You can block out unwanted wavelengths, but not change those
incoming to the film. Filters mask off certain spectral bands,
reducing the total photon flux, but do not actually relocate the
photons to a new band.

---
þ RoseReader 2.52á P005004

Benoit Morrissette wrote in message . ..
On 29 Jul 2003 13:15:10 -0700, (Art) wrote:

I have been dabbling in color prime focus astrophotography for some
time now. I have never tried black and white, but I recently aquired
a photographic enlarger, and some film and paper development equipment
for black and white films. I have several questions about black and
white astrophotography.

1. I can't afford a lumicon hypering chamber and the gas for it. Is
there any alternative to this? In the hopes of somehow devising my
own setup, I've looked locally for a someone who can get
hydrogen/nitrogen mixture, but no one really wants to fool with it for
such a small amount.

There is another way to hyper a film: just give it some light to start!
The technique is touchy: you need to expose the film to some light
just enough so that it barely begins to darken. The reason for this
is called "hysteresis", the silver grains needs a few photons before
they begin to react... The problem: you only have a few hours after
to take your pictures AND to develop the film.

2. I really dont want to hyper the film anyway, is there any kind of
black and white film I can use that doesn't need to be hypered? I
read in Micheal covington's book that tmax400 (or was it 100?) was ok
if you could not get hypered film. Would I need to select my targets
carefully? Also I can't find many pictures on the internet in black
and white with anything other than techpan.

TechPan is a very high contrast, very fine grain scientific film. I have seen
very good results, some of them better than Techpan with TMax400. I
suggest that you try too Ilford Delta 400, Delta 3200 ( this one may be too
grainy) and the superb XP2 400. The XP2 is a very fine grain, very very wide
dynamic range BW film that must be developped in C41 (color) chemical.
More info at http://www.ilford.com/html/us_english/bw.html


Ok, now for the outlandish questions ...
3. Is there any other thing that black and white film can be treated
with that would make it better for astrophotography? Perhaps
something that would shift the "spectral sensitivity curve" slightly
toward the red?
Most silver halides used today are not sensitive to red light so the
manufacturers have to use chemical tricks to do exactly what you are describing
here. There are two kinds of BW film on the market today: OrthoChromatic ones,
sensitive only to green and blue and PanChromatic ones. Why do you think they
always use the word PAN in the name of many films?!?! It was quite
a fabulous shock when Kodak got the first Panchromatic film in the
30's. Remember the funny make-up for the actors of the old movies?

BTW, BW papers are not treated that way so that we can develop them
with a red safety light.


And, the truly absurd ...
4. Is there anyway to change the color/wavelength of the light on the
way to the film, so that the film would respond better to it?


It is not absurd because there exist a physical process by wich we can change
the wavelength of light. It is called the "Doppler red shift". Suppose
you want to take a picture of a very old globular cluster. Because it is old,
most of its stars are reddish. So we want to shift the wavelength toward the
blue end of the spectrum.

All you have to do is to fly AWAY from the cluster while taking your picture.
You can begin with a speed of about 100 000 kM/s ( a third of the speed of
light) to see if it shift enough for you. You then accelerate or deccelerate
to get a good color balance...

thanks for any help you can provide here. Anything at all ...

Thanks very much everyone for your answers. I've recieved several now
here and privately. It has been most informative. I have several
ideas now, and we will see. (I'll probably save the Doppler Shift
idea until I'm a little more desparate ).

By the way, on the subject of changing the response to red for film
.... anyone ever heard of this:
http://www.hwsands.com/productlists/...es/sda2496.htm
Think it would help? Probably not, just curious.

Anyway again Thanks to everyone who responded. I've learned a lot.

Art