Monday, June 17, 2013

Ortho Still Life

Fruit & Nuts

Nothing super exciting in this photo. It was taken with my 1951 Speed Graphic press camera. I used the Optar 135mm lens set at f/5.6 (note the shallow depth of field). The interesting thing about this photo is that the red parts of the apple on the right are very dark. This is what you would normally see with a green filter, however in this case I just used Kodak CSG (Clinic Select Green) x-ray film (see X-Ray Vision). This film is orthochromatic which means that it is 'blind' to certain parts of the visual spectrum. In the case of 'Green' x-ray film, it is more sensitive to green light and less to red light. There is also 'Blue' x-ray film which is more sensitive to blue and less sensitive to red (yes, red gets shafted in both cases). These sensitivities have to do with the intended use of x-ray film, which is to take x-rays (surprise!). The film holders have a fluorescent screen in them which fluoresces a certain color (blue or green) when the x-rays hit it. That shortens the exposure time and thus lowers the dose of x-rays the patient gets.

I took some portraits recently with both x-ray and panchromatic film just to see the difference with skin tones. I'll put those up as soon as I get them developed. Until then, drop a comment about how you are using x-ray film or 4x5 cameras or anything interesting you are doing in your photography.

Cheers!