Pinhole insanity or f/64

Geeking out on camera stuff lately.

An interesting project is the quality Canon EOS pinhole lens.

I’ve got it completely engineered and the hard parts solved. I just need to get up off my butt and make it. It’s funny how some simple projects sit. Maybe posting this will spike some interest.

Designed around 34mm EF-S f/129.7 and f/64. 34mm is a ‘normal’ lens for EF-S, equivalent to 54.9mm for EF.

Note 34mm was the shortest ‘literal’ focal length possible on my Canon 40D camera. Any shorter and the mirror would be blocked.

Filter threads for 48mm filters.

Lord Rayleigh’s formula: (a rule of thumb for pinhole apature diameter)

d = 1.9 x √ (f x λ)


d is the diameter of the hole

f is the focal length (the distance from the hole to the sensor or film)

λ is the wavelength of the light

For visible light, the average wavelength is 0.56 mm (0.00056mm)


f = 34 mm EF-S (equivalent to 54.9mm EF, 44.9 degree diagonal view) Note: This is the minimum mechanical focal length possible on my Canon 40D.

d= 0.262 mm or 0.0103″


F-stop = f / d

Thus, f/129.7


For f/64, d = 0.53125mm or 0.0209″

For f/64 (See: Group f/64)