View Full Version : Ortho films, what for ?

22-May-2010, 00:25
Hello friends,

I currently use TMAX 100 and 400 films with satisfaction.
As I was following a workshop whose goal was to better my knowledge of my view camera, the teacher told me that an ortho film is better to photography foliages.

Have you ever heared something like this, or do you use this kind of film this way ?


Emmanuel BIGLER
22-May-2010, 01:23
In the long history of films, first came silver-halide layers sensitive to blue only, like graded photograpihic paper, then the sensitiviy was extended to green and yellow as orthochromatic fims, then extended to red to become panchromatic. This is not a new story, since the silver halide emulsion used by the Lumière brothers in their autochrome plates (patented in 1903 !) was already panchromatic.
Ortho film are not sensitive to red, this can be a drawback in most photographic situations.. except for foliage.
With a panchromatic film I know that adding a green filter allows you to capture subtle tones in green foliage. The green filter cuts-off some portions of the red spectrum as well as some parts of the blue. A yellow filter only cuts the blue part of the spectrum and lets the green and red enter the camera.

Modern ortho film is used for certain graphic arts processes, (at least were used, since most graphical art is going digital). For example to make black and white slides from black and white negatives by contact printing. As inter-negatives for the alternative processes.
You can process an orthochromatic film by inspection under a red safelight.
Orthochromatic films can be either of high contrast or continuous tones and their resolving power is often higher than regular panchro films.
Unfortunately continous tone ortho films tend to be more expensive than panchromatic films, hence it might be cheaper to add a green filter in front of your camera loaded with panchro film..

Doremus Scudder
22-May-2010, 01:48
To expand on Emmanuel's comprehensive and informative answer.

A minus-red filter, i.e., Kodak Wratten #44 or equivalent when used with panchromatic film will approximate orthochromatic response. These are usually found in gel form.

Orthochromatic film, or pan film with a #44 renders foliage and shadows in a way that is difficult otherwise. It is a specific "look" that comes from the red not being recorded and the blue and green predominating. Skies are lighter, shadows and green foliage are lighter, while reds are rendered almost black.

I sometimes slip a #80A filter (blue tungsten-to-daylight color-compensating filter) on as well for foliage, when the #44 is not practical (not with me, or there is too much wind for gels). This cuts less sharply, but still boosts the foliage and shadows somewhat while darkening reds.

Hope this helps

Doremus Scudder

22-May-2010, 06:52
Emmanuel and Doremus, thank you for the answers.
I now know that I can keep my TMX films and, with a filter, get the rendering of an ortho.


Rick A
22-May-2010, 07:23
I've been experimenting with Orthe film for a couple of months, and totally love the look for portraiture. Adox Ortho 25 for MF and Ilford Orthe Plus (asa 80) for LF. all I can say is WOW! These are both contrasty, but easily tamed with proper filteration, and development. Be forwarned, unfiltered ortho will render blue sky as white, almost blown out, and miserable to deal with, but brought under total control with a green filter. Red filters have zero effect, as there is no red sensitivity. Yellow, green and blue , are all you need. I havent used a polarizer as yet, but I dont see where it would be any different than with panchromatic film. The main thing I like about ortho, is handling under red safelight without any fogging. I can load and develope without having to go lights out.

W K Longcor
22-May-2010, 07:40
Just an "add-on" to the comment about using ortho for portaiture. I used to love the effect of tri-x ortho for portaits of men -- gave them a strong, rugged look.

22-May-2010, 19:36
i miss tri x ortho ..
it was one beautiful film
and it wasn't asa 4, but 400 ...