Light source for Pyro negs

In article ,
"Francis A. Miniter" wrote:

Velvia is a color slide film, so its emulsion will have multiple layers. As
will color negative film. But not B&W film,....

But the emulsions themselves are not divided into
layers.

Actually in truth I know of an exception w/regard to B&W
film. That is Forte 400 speed film. The literature states
that it does in fact have two seperate emulsions which allows
it to capture highlights independant of midtones and shadows,....
whatever that means.
--
LF Website @ http://members.verizon.net/~gregoryblank

"To announce that there must be no criticism of the President,
or that we are to stand by the President, right or wrong,
is not only unpatriotic and servile, but is morally treasonable
to the American public."--Theodore Roosevelt, May 7, 1918

In article ,
Uranium Committee wrote:
Andrew Price wrote in message . ..
On 2 Dec 2004 13:00:11 -0800, (Uranium
Committee) wrote:

Get out of this thread and shut the **** up!

I see that Mr Scarpitti is in fine form this evening.

Well, I'm heartened that you appreciate my modest contribution.

The number of technnological illiterates who profess some knowledge of
the technical aspects of photography is staggering.

You mean, like when you insisted just now that "all" film has multiple
emulsion layers, and then hastily backpedaled?

--
Thor Lancelot Simon
But as he knew no bad language, he had called him all the names of common
objects that he could think of, and had screamed: "You lamp! You towel! You
plate!" and so on. --Sigmund Freud

On Fri, 03 Dec 2004 01:47:57 GMT, Gregory W Blank
wrote:

In article ,
"Francis A. Miniter" wrote:

Velvia is a color slide film, so its emulsion will have multiple layers. As
will color negative film. But not B&W film,....

But the emulsions themselves are not divided into
layers.

Actually in truth I know of an exception w/regard to B&W
film. That is Forte 400 speed film. The literature states
that it does in fact have two seperate emulsions which allows
it to capture highlights independant of midtones and shadows,....
whatever that means.

Thanks for that, Greg,

That was a trick, well a design decision, employed with Ansco Super
Hypan (GAF 500) in which there were two distinctly different emulsions
used to extend the range of the film from shadow to highlight with
normal, averaging exposure methods. It worked pretty well to give
predictable results in rangy situations. At the time, many
photographers were dwelling on pushing film to its maximum and
slighted the benefit of the sharp toe rise of this film, which, if
respected, could give a very deep black with good middle tone contrast
and recoverable highlight detail.

Tri-X, with its very long toe and more pronounced shoulder lent itself
to pushing, and seemed to be more in favor.

I'm not sure, but Dupont made a film called SX Pan, or something like
that that may have been similar to the Ansco product as its claim to
fame was that there was no practical shoulder.

Whether these were two layer coatings, I believe the Ansco product
was, or a single, mixed coating, is really irrelevant here. The
question was about papers, and that seemed to be quite clear in the
case of the Ilford documentation; it is a single, mixed emulsion.

Now, even that is not really relevant to the original argument about
the use of Pyro staining developers.

Yes, Pyro stained negatives give additional density to the highlights
of blue sensitive papers.

Yes, Pyro stained negatives give a variable, highlight detail enhacing
effect with VC papers.

Yes, this is useful and controllable.

Just listen to the folks who do it all the time.

But, of course, Greg, you already do that. I wish the other one with
no name would do so, too and then, shut up.


Robert Vervoordt, MFA

On 2 Dec 2004 22:29:56 -0500, (Thor Lancelot Simon)
wrote:

In article ,
Uranium Committee wrote:
Andrew Price wrote in message . ..
On 2 Dec 2004 13:00:11 -0800, (Uranium
Committee) wrote:

Get out of this thread and shut the **** up!

I see that Mr Scarpitti is in fine form this evening.

Well, I'm heartened that you appreciate my modest contribution.

The number of technnological illiterates who profess some knowledge of
the technical aspects of photography is staggering.

You mean, like when you insisted just now that "all" film has multiple
emulsion layers, and then hastily backpedaled?

Right, Thor, and it bears repeating.

Robert Vervoordt, MFA

Szaboht wrote in message . ..
I'm not yet experienced with Pyro development, but I'm considering to give
it a try. My questions concern the enlarger lamp for pringing pyro
negatives. I read frequently that a cold light head is best for pyro
negatives (presumably due to the yellowish stain on the neg), but I have a
standard tungsten halogen lamp in my only enlarger, an Omega D2 with Super
Chromega color head. I hope to use VC paper (Forte and Kodak).

If the spectrum really must be close to that of a cold light head, is there
a filtration offset that can be dialled into on the enlarger's color head
to closely simulate the spectrum of a cold light lamp? Or, with regard to
pringint pyro negs, is the spectral difference between cold light and
tungsten halogen too small to be concerned about?

Regards,
Szabo

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Bear in mind that certain combinations of techniques match well,
whereas others do not.

Pyro has some advantages for cold-head printing, because it increases
the contrast WITHOUT increasing development (increased development is
undesirable because of increased grain and fog). Cold heads are
diffuse sources and have low contrast therefore. Cold head tubes
produce a fairly high-color temperature (bluish) light, though some
special tubes with lower color temp are available.

VC papers are designed for use with tungsten sources of about 2850K.
VC papers are not really intended to be replacements for graded
papers, which are generally of superior quality. VC papers are really
intended more for convenience than for ultimate quality. If VC papers
were capable of ultimate quality (they're not), then graded paper
would no longer be in demand.

Cold light/diffusion + pyro/staining developer + graded paper is one
high-quality combo. It used generally with large-format film. It is a
poor choice for small formats.

Tungsten/condenser + conventional/nonstaining developer + graded paper
is another high-quality combo. It is used generally with miniature
film for ultimate quality, but is also widely used for large-format
work.

Tungsten/condenser + conventional developer + VC paper is a
'convenience' combo. It is used generally with miniature film.

A color heads can also be used with VC or graded paper, but offers
lower contrast than condensers. I don't use one for B&W work.

If you want to use pyro with a cold head, use a graded paper.

Szaboht wrote in message . ..
I'm not yet experienced with Pyro development, but I'm considering to give
it a try. My questions concern the enlarger lamp for pringing pyro
negatives. I read frequently that a cold light head is best for pyro
negatives (presumably due to the yellowish stain on the neg), but I have a
standard tungsten halogen lamp in my only enlarger, an Omega D2 with Super
Chromega color head. I hope to use VC paper (Forte and Kodak).

If the spectrum really must be close to that of a cold light head, is there
a filtration offset that can be dialled into on the enlarger's color head
to closely simulate the spectrum of a cold light lamp? Or, with regard to
pringint pyro negs, is the spectral difference between cold light and
tungsten halogen too small to be concerned about?

Regards,
Szabo

----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

Bear in mind that certain combinations of techniques match well,
whereas others do not.

Pyro has some advantages for cold-head printing, because it increases
the contrast WITHOUT increasing development (increased development is
undesirable because of increased grain and fog). Cold heads are
diffuse sources and have low contrast therefore. Cold head tubes
produce a fairly high-color temperature (bluish) light, though some
special tubes with lower color temp are available.

VC papers are designed for use with tungsten sources of about 2850K.
VC papers are not really intended to be replacements for graded
papers, which are generally of superior quality. VC papers are really
intended more for convenience than for ultimate quality. If VC papers
were capable of ultimate quality (they're not), then graded paper
would no longer be in demand.

Cold light/diffusion + pyro/staining developer + graded paper is one
high-quality combo. It used generally with large-format film. It is a
poor choice for small formats.

Tungsten/condenser + conventional/nonstaining developer + graded paper
is another high-quality combo. It is used generally with miniature
film for ultimate quality, but is also widely used for large-format
work.

Tungsten/condenser + conventional developer + VC paper is a
'convenience' combo. It is used generally with miniature film.

A color heads can also be used with VC or graded paper, but offers
lower contrast than condensers. I don't use one for B&W work.

If you want to use pyro with a cold head, use a graded paper.

I thouht we areed to ignore this person.

--




Keep working millions on welfare depend on you
-------------------

I thouht we areed to ignore this person.

--




Keep working millions on welfare depend on you
-------------------

I thouht we areed to ignore this person.

--




Keep working millions on welfare depend on you
-------------------

Andrew Price wrote:
: On 2 Dec 2004 13:00:11 -0800, (Uranium
: Committee) wrote:

: Get out of this thread and shut the **** up!

: I see that Mr Scarpitti is in fine form this evening.

It's also why we agreed to ignore him a while back. Contrary to what I
first thought it worked and he all be vanished. I would like to suggest
that we go back to starving him of the attention that he so craves.
--




Keep working millions on welfare depend on you
-------------------