Freitag, 8. Juli 2011

Sharan-pinhole-camera 35 wide. How to calculate the exposuring time

This is a little how to, to calculate the exposure time for this pinhole camera.

Material list:

Calculate the exposing time:
For that do I use my Motorola DEFY smart phone, and the free app “beeCam Lightmeter”.

//info: I had to adjust the light meter in the menu point “sensor correction” with the value of 10.0. I guess this number is different from phone to phone. To adjust, go out at 12 o'clock on a sunny day and start the app. If you have 100 000 lux the adjusting is right. lux on wiki
ISO set to 100
F to 32.

The app would be perfect if it could be set to f 180. but the maximum is f32. For that reason you have to calculate the expose time from f32 to f180. The factor for that is 32. f stop list on wiki ( exposure time for f32 x 32= exposure time f180)

If you use the ILFORD FP4 film, and got a longer exposure time than a 1/2 second. You have to adjust the exposure time. See the graphic on site 2. pdf
for that reason I done this smal table.

On the left is the time from the “ beeCam Lightmeter app” ISO= 100, f32. In the middle, the time for f 180 and right the time with the adjustment for the ILFORD film.

Now you are ready to take photos with the sharan pinhole camera.

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