Graflex.org

[coyote]

I have not had my Crown Graphic very long and the first photos I took were with 10 year old unrefrigerated slide film. Recently I took some Velvia shoots with a another camera and with the front element off the Schneider-Kreuznach 150/260 mm lens. I shot the same settings for both cameras and the final result were identical (except for being different focal lenght). But I see that the maximum aperature for the lens is different if it has the front element on or off. Do I have to set this on the shutter and would shots taken at the same setting be over exposed on the 150 mm compared to the 260mm? I have taken some shots since that but as I have to ship them out of town for processing I would like to shoot some more first.
REcommendations for a wider angle lens for my camera. How much wider would the 127 be?

Ivan Shukster (the same age but not in as good shape as the Graflex)

[Les]

There should be a secondary f-stop scale to use the single rear element. Yes you will loose light when shifting between both elements and the rear. Remember than an F number is the relationship between the diameter of the iris and the focal lenght. If you keep the iris the same but change the focal lenght, then the f-number increases.

For instance: f8 on a 150mm lens gives an aperture of 18.75mm in diameter. (150/ But an aperture of 18.75mm on a 260mm lens equals f 13.8 roughly a 1 1/3 stop loss 260/18.75).




[ This Message was edited by: Les on 2002-09-12 18:54 ]

[coyote]

Thanks that is what I thought. When I take the front element off I can see the secondary values. Now I am thinking that perhaps this shutter is 2 stops off as the exposure was set according to the meter and set with the primary aperature ring. Have to see what happens with the developing. Need them to test one first before they develop the rest.

Ivan Shukster