If I want to do a 24h exposure with an ISO 100 film, how do I calculate which aparture I should use?
It's about 18h of light, 2h of twilight and 4hours of darkness.
If I want to do a 24h exposure with an ISO 100 film, how do I calculate which aparture I should use?
It's about 18h of light, 2h of twilight and 4hours of darkness.
well, the smallest one you got........
an then there's reciprocity.
well its a pinhole-camera and I have ND-filter aswell, but is there any way to calculate roughly?
Try one and see what you get and go from there?
The overnight won't register at all compared to the daylight unless you use very different filtration/aperture at night.
18 hours is 64800s, which is 16 stops more than 1s. Ignoring reciprocity failure (i.e. use Acros or TMY2 and aim for about 2 stops overexposure) and brightness variation through the day, you can take it from there. If you use a traditional film with poorer reciprocity characteristics, it's going to be a complete guessing game.
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