Fortunately, you can loosen three grub screws around the snout of the lens and rotate the focus ring without moving the lens, line it up properly, and tighten it up again.
To calibrate the focus, you will need:
- a bright and high-contrast object a known distance from the camera
- some tracing paper or other diffuse translucent material
And here’s how we do it.
- Set up the camera on a tripod with the back open/removed. Attach the tracing paper where the film would usually go, like so:
- Put your bright object a known distance from the camera, and measure it. Call this distance X. If working indoors, try using something like a desk lamp or a TV screen (both are bright, with strong edges). If working outdoors, you could use a building with strong features (and pace out the distance from your camera).
- You might need to cast a shadow over the paper to see your image, but it should be there, albeit upside down.
- Focus the image so it is sharp. It can be hard to tell if the image is sharp, so you could use a magnifying glass to inspect it.
- When you’re happy that the image is in focus, you know that whatever your focus is set to now is X. Loosen the focus ring, readjust to that value, and tighten.
You’re done! Happy shooting.