Pinhole Exposure Calculator

Pinhole Exposure Calculator Charts

Pinhole photography is becoming more and more popular for different reasons. For some it’s a way of starting out in film photography and for others, it’s a way of exploring different techniques, going back to bare basics and homing in on their skill levels.

I personally use a ZeroImage 2000 Pinhole camera which uses 120 roll film and produces 6×6 medium format negatives.

A friend of mine, Martin Henson uses a ZeroImage 54 which is a 5×4 pinhole camera which produces 5×4 negatives.

Pinhole cameras have a very high aperture f number due to the size of the pinhole used. In most cases, these high aperture values exceed what a traditional light-meter can use.

Calculating Pinhole Exposure Times

Fortunately there is a simple workaround which we can use which allows us to measure the light with our light-meters at a given f number and then work out the correct exposure for the pinhole camera.

Let’s look at an example at calculating pinhole exposure time by using f/22 on our light meter.

Pinhole Camera Exposure Multiplier

If we divide the f number of our pinhole camera by f/22 ^2 this will give us an exposure multiplier number.

Zero Image 2000 Pinhole f/138

Dividing the 138 by 22 ^2 gives us 39 so in the case of the Zero Image 2000, the multiplier is 39. If we place a sticker on the camera with M39 on it, when out in the field, all we do is take the exposure reading at f/22 and  x it by 39.

One thing to remember is that this time does not take into account any film reciprocity it may have.

Our light-meter set to f/22 says the exposure time is 1/4 of a second. Multiply 1/4 x 39 = 9.7 seconds.

Zero Image Exposure Charts

To make life easier, I created a set of Pinhole exposure charts for both the Zero Image 2000 and Zero Image 5×4 pinhole camera. The 5×4 Zero Image Pinhole camera can accommodate up to three focal lengths, 25mm, 50mm and 75mm. The exposure charts include all three.

Zero Image Exposure Charts


Zero Image Pinhole Examples

Pinhole Exposure FAQ

I have some Free pinhole exposure calculator charts for the ZeroImage Pinhole camera which can be downloaded from the Ian Barber Photography website.

An alternative to using a pinhole camera exposure time calculator for the ZeroImage 2000 Pinhole camera is to download my Free pinhole camera exposure time calculator charts from <b>Ian Barber Photography</b>

The aperture number of the ZeroImage 2000 pinhole camera is f/138.

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