[Alt-photo] [Alt-Photo] Wet Plate Collodion Sensivity Filterfor Normal Film

`Richard Knoppow dickburk at ix.netcom.com
Sun Sep 10 23:27:57 UTC 2017

     I don't know what blue sensitive or "color blind" film is 
available. At one time Kodak Release positive was available for making 
B&W prints of motion pictures was also available as sheet film for 
making lantern slides but its long gone. Its emulsion was similar to 
bromide printing paper. Very slow stuff.
    Blue sensitive or "color blind" emulsions distort the tonal 
rendition of a scene, especially colors. Lips tend to be rendered black 
and skin blemishes are exaggerate. Blue sensitive film was available for 
many years for special purposes including those were accurate gray scale 
rendition of color was not necessary. "Commercial" films tended to be of 
the color blind type.
     I am not sure when orthochromatic films were introduced. They are 
sensitive to green as well as blue, some are sensitive into the yellow 
range. They have much better rendition of color than color blind films. 
Ortho films were the standard of the motion picture industry until about 
the introduction of sound when the change in lighting from arc to 
incandescent, necessary because the old arc lighting was noisy, required 
a film more sensitive to the predominantly red output of tungsten 
lighting. This, in turn, required a complete change in makeup, costume 
design, the way sets were painted and more. Also, early pan films tended 
to be lower in contrast and grainier than ortho film so of the time so 
there was some resistance to using it. Another factor was that early 
motion picture practice was to develop negatives by inspection, not 
possible with  pan.
    Ortho was useful for "character" portraits since it tended to 
exaggerate skin textures, thought desirable for male portraits. So you 
will find films like Kodak Ortho Portrait listed in the older books. The 
overall rendition is partly due to the spectral sensitivity and partly 
due to the overall curve of the films. There are still some ortho films 
made but I think the choice is limited.

On 9/10/2017 12:16 PM, Mustafa Umut Sarac wrote:
> I thought old timers and their lenses and the modern platers , they 
> all use variety of glasses. I agree with you richard.
> Thank you for Roscoe link , 51 mm x 51mm dichroic filter goes from so 
> 30 dollars.
> I saw some terrible orthochromatic pictures and some good. I dont have 
> idea what will go with me .
> I will use 135mm Leitz Hektor on portraits with Soviet Zorki. I think 
> uv focus must be studied with my lens. Good warning.
> Now there remains two questions , why not ordinary bw film but blue 
> sensitive film ? Does it make difference ?
> Second question, does wet plate have regular crystals or what ? I used 
> 9 Leicas and all for their critical area noise.
> I think I can get noise with Hektor  I think leica makes lenses as 
> film as friend. They go together very well.

Richard Knoppow
dickburk at ix.netcom.com

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