16 to 12 Overlap – Cozumel with a Holga

Your Holga 120 medium-format camera has two aspects involved in moving between the standard square image size which fits 12 images on a roll and the tall rectangular size which fits 16 images on a roll. One step is to add in the physical insert into the camera which restricts the light from only hitting a rectangular shape on the film, so you create the rectangles rather than squares. The second step is to slide the arrow-pointer on the back of the Holga so it points at the number 16 rather than the number 12. This ensures, as you are manually cranking your film forward, that you stop at the appropriate spot for each new 16th section of the film, rather than the normal 10.

But what happens if you only do one of those two steps? What would happen if you left the innards of the camera with its standard square image-taking process. But imagine you then changed the arrow so it pointed to the 16, so as you found the film it took you only to each 16th of the film rather than the full 12th. What would it do?

Let’s think about this logically. The camera itself, physically, is in square image-taking format. There is no insert artificially constraining the camera to only expose a rectangle of film. Therefore the full square image of film is going to be exposed each time. Each time you press the shutter release, a square of film will be hit by light.

However, when you crank the advance wheel, you will not advance fully to the next blank square space. Instead, you will only crank forward 1/16th of the film rather than the full 1/12th of the film. You will not quite get clear of the square you just exposed.

That means when you take the next photo, you’re going to overlap with the previous one. The 16 counter assumes you’re taking tall narrow rectangles with a height taller than the width. What you’re actually doing is taking squares. So the edge of each square will overlap with the next. The only exception is the very first and very last square. Each of those will only overlap on one side.

So that is what you see here. I was exploring Cozumel and the San Gervasio ruins. I was taking photo after photo. But because I was not quite winding far enough ahead, each photo overlapped with the one before it and the one after it. You can see that on the edges.

Photo by Lisa Shea

In the center you see the jungle trail I was walking on. On either side you see the edges of temple images I had taken before and afterward.

This was taken with Kodak Portra 400 Pro ISO 400 Color film.

This film was developed at https://oldschoolphotolab.com/

The impacted image is why it’s always so important to sync what insert you put into your camera with the indicator on the back, unless you’re aiming to do something fun.

Image Size Indicator on a Holga