Introduction

You have a lens and a camera that use two different mounts, and you are wondering whether it is possible to combine the two.

This article focuses on more complicated cases where no commercial adapter exists and you need to come up with your own solution.

A quick disclaimer: if you damage your camera and/or lens, I am not responsible in any way. But unless you try experimental things, adapting a lens is very safe and will not cause any issue.

Before You Start

Before considering adapting a lens to your camera, several factors must be taken into account:

1) Achieving Infinity Focus

To focus at infinity, the lens must sit at a minimum distance from the sensor or film plane.

If it is impossible to position the rear of the lens close enough to the sensor, infinity focus will be impossible and you will be limited to close-up or macro photography.

If the lens flange distance is shorter than that of your camera mount, all hope is not lost:

With a mirrorless or rangefinder film camera, there is no mirror blocking access to the sensor or film plane.

Therefore, if the diameter of the rear barrel of the lens you want to adapt is smaller than your mount opening, you can still start considering an adaptation.

Another solution, if the rear barrel diameter prevents the lens from being inserted deeply enough (or if a mirror gets in the way), could be to disassemble the lens and modify the focusing mechanism to gain a few extra millimeters.

That is not the most desirable approach, however.

2) Does the Lens Cover the Entire Sensor Area?

There is little point in adapting a lens that only covers a small fraction of your sensor.

For example, a lens designed for 35mm film will probably not fully cover a medium format sensor.

3) Modern Lens Specificities

Some functions (aperture, zoom, and focus) are now controlled entirely through electronic communication.

If you plan to solve focusing issues with an external helicoid, make sure your lens does not rely on floating elements for focusing.

Tools and Ideas for Adapting a Lens (in no particular order)

Using glue or tape
Salvaging the mount from a broken lens or camera and gluing it
Using extension tubes or helicoids (more precise)
3D printing
Etc.

In short, anything is possible as long as it works. Do not limit yourself when looking for solutions.