Phenidone Extended Developer

OK I'm looking at some "alternative" processes on the PhotoFormulary site.
It says Phenidone Extended is capable of 15 to 20 stops of exposure range.
When would I need this? and how do you print 15-20 stops on paper? Is it
just giving me more choice as to what area I'm going to print? Is this
strickly large format formula or does 35mm and medium benefit from this too?
Thx. Oh and what kind on negative do I use this with?

CCDee wrote:
OK I'm looking at some "alternative" processes on the PhotoFormulary site.
It says Phenidone Extended is capable of 15 to 20 stops of exposure range.
When would I need this? and how do you print 15-20 stops on paper? Is it
just giving me more choice as to what area I'm going to print? Is this
strickly large format formula or does 35mm and medium benefit from this too?
Thx. Oh and what kind on negative do I use this with?


Doesn't sound like an "alternative" process, more like a POTA -like
developer for wide range lighting or contrasty materials.

What's a POTA?

"nicholas" wrote in message
...
CCDee wrote:
OK I'm looking at some "alternative" processes on the PhotoFormulary
site.
It says Phenidone Extended is capable of 15 to 20 stops of exposure
range.
When would I need this? and how do you print 15-20 stops on paper? Is it
just giving me more choice as to what area I'm going to print? Is this
strickly large format formula or does 35mm and medium benefit from this
too?
Thx. Oh and what kind on negative do I use this with?


Doesn't sound like an "alternative" process, more like a POTA -like
developer for wide range lighting or contrasty materials.

P.S. Right or wrong, I consider anything that's not D-76 "alternative". ;^)

"nicholas" wrote in message
...
CCDee wrote:
OK I'm looking at some "alternative" processes on the PhotoFormulary
site.
It says Phenidone Extended is capable of 15 to 20 stops of exposure
range.
When would I need this? and how do you print 15-20 stops on paper? Is it
just giving me more choice as to what area I'm going to print? Is this
strickly large format formula or does 35mm and medium benefit from this
too?
Thx. Oh and what kind on negative do I use this with?


Doesn't sound like an "alternative" process, more like a POTA -like
developer for wide range lighting or contrasty materials.

You would need it when there were extreme light values in the shot. These
developers were originally designed to photograph explosions with fairly
normal film. Sometimes you run into situations which require N-4 or N-5
development, such as a brightly sunlit wall illuminating an interior by
reflection, where there is detail in both the shadows and the highlights.
This sort of developer is useful there. The other place where it is useful
is when you need low to normal contrast with inherently high contrast film,
such as Kodak Technical Pan.

"CCDee" wrote in message
news:siuoc.430132$Pk3.254813@pd7tw1no...
OK I'm looking at some "alternative" processes on the PhotoFormulary site.
It says Phenidone Extended is capable of 15 to 20 stops of exposure range.
When would I need this? and how do you print 15-20 stops on paper? Is it
just giving me more choice as to what area I'm going to print? Is this
strickly large format formula or does 35mm and medium benefit from this
too?
Thx. Oh and what kind on negative do I use this with?

POTA is a very, very soft working developer that can be used to get a full
range of continuous tone gray scale from very contrasty films like
microfilm. It is extremely simple: phenidone, sodium sulfite, and water. It
is prone to streaking and mottling if not properly agitated.

David Foy

"CCDee" wrote in message
news:Ejwoc.457043$Ig.82356@pd7tw2no...
What's a POTA?

"nicholas" wrote in message
...
CCDee wrote:
OK I'm looking at some "alternative" processes on the PhotoFormulary
site.
It says Phenidone Extended is capable of 15 to 20 stops of exposure
range.
When would I need this? and how do you print 15-20 stops on paper? Is
it
just giving me more choice as to what area I'm going to print? Is this
strickly large format formula or does 35mm and medium benefit from
this
too?
Thx. Oh and what kind on negative do I use this with?


Doesn't sound like an "alternative" process, more like a POTA -like
developer for wide range lighting or contrasty materials.