Salmon Bay Bridge (Bridge No. 4), Seattle, WA
This comparative example shows panchromatic film with a yellow (K2) filter (left), compared to orthochromatic (blue-sensitive) film with no filter (right). The inherent characteristic of ortho film to render the sky considerably lighter than panchro film, helps to emphasize the design of the bridge truss and superstructure. I have experimented with using a blue filter paired with panchromatic film to simulate the look of ortho, but found the trade-off in effective film speed to be objectionable. I rate Ilford’s Ortho Plus and FP4 at iso 80. I process the Ortho Plus with Fomadon diluted 1:50. Since orthochromatic film is available in 4x5 and 8x10 but not in the 5x7 format, I purchase it in 8x10 and trim it down to 5x7. The guide notches are then added manually. The film can be handled under a Kodak #2 deep red safelight, making this process relatively easy. Shot with a 180mm Schneider lens, 1/2 and 1/4 second at ƒ32 respectively.