Back in 1996 when I began photographing landscapes with a pinhole camera, I used Kodak Commerical film, often referred to as blue sensitive. Kodak discontinued manufacturing Commercial sometime in 2002 due to its specialized nature and limited demand. I switched to Ilford Ortho after my Kodak stock ran out.
In the early days of photography, before the arrival of panchromatic films, emulsions tended to be limited in their ability to record light. These emulsions favored blue light, hance the names 'blue sensitive,' 'color blind,' or 'ordinary film.' Visually, what this means is that the areas that are strong in blue light, like skies and water, are rendered in pale tones in the final print. Objects that are red, green orange, or yellow are rendered in very dark tones. Skin tones, which have a lot of red, are rendered fairly dark. Vegetation that is heavy in green looks virtually black in the final print. This particular 'palette' of tones is quite evident in the photographs of 19th century photographers Edward Curtis, Carleton Watkins, Timothy O'Sullivan, and William Henry Jackson.
As far as the technical aspects of using blue sensitive film, my ISO rating is 25 and exposures with the pinhole range from a short 4 seconds at high noon on a cloudless Colorado day to about 40 minutes at sunset. Typical exposures are around 2-3 minutes. Reciprocity failure is an issue, especially in terms of contrast, and the long pinhole exposures compound the situation. The zone system goes basically out the window with blue sensitive because it is virtually impossible to judge how much blue light is falling on a given subject at a given time. Sunrise and sunset can throw exposure times in part because the light is visibly redder where the film has greater difficulty recording information. The film is developed using Inford Microphen 1:3, 9 minutes at 68 degrees. Pinhole negatives vary wildly in contrast, so I adjust my developing times based on experience and instinct. After 9 years with this particular film and camera combination, there are very few surprises.