Rules of Thumb

[dickbromberg]

I am using a pinhole camera and film with the following characteristics.
I will be shooting (for the time being) in bright sun only.

35mm Kodak T max 100 film
pinhole diameter .25 mm
length from pinhole to film 38 mm
using a pinhole calculator (www.mrpinhole.com) the fstop is f 152 .

These are the particulars of my present camera and I would like to know if there is a rule of thumb for exposure time to use, at least as a starting point.

But in a more general sense I'd like to be able to estimate starting points when these parameters change, for example when I build another camera with other parameters.

thanks
Dick Bromberg

OOPS .... I just went back the the pinhole calcluator and found that it actually gives a sunny day exposure time of 1/2 seconds. Is this actually correct ?

 

[Ole]

Let's see...

The "Sunny 16" rule says f:16, 1/EI seconds.

F:16 to f:152 is about 6 1/2 stops (6 stops is f:128, 7 stops is f:180).

6 1/2 steps up from 1/100 is about 1/2 second.

Yes, it seems that that is correct.