Homemade Camera Lens





Introduction: Homemade Camera Lens

Want to make a lens yourself?

You can see the finished product in the photo above beside the bulk of the standard kit lens!

It is truly fun and only takes a few minutes to build, (please) remember to vote for me in the contest!

Step 1: Finding the Lens / Equipment Needed

You need a lens to make a camera lens, and a way to attach it to the camera.

The lens can be from a magnifying glass or just about anything.

I've made both my lenses from old glass, you can buy cheap glass online that wouldn't be scratched.

Equipment needed:

Toilet paper roll / Kitchen towel roll (empty)


Duct tape

Tape Measure

Attaching to the camera:

I use a telescope adapter to connect the lens, and can slide the lens front and back to focus.

Step 2: Measuring and Calculating Focal Distance

After finding the lens you need to measure the focal length.

You can do this by standing on the other side of a big room from a point of light, in my case sun shining through a window.

Next measure the distance between the centre of the lens and the image focused on a surface.

In my case it was around 120 mm.

Now you need the flange distance of your camera. This wikipedia article can help with that: https://en.wikipedia.org/wiki/Flange_focal_distance

For a Pentax mount it is around 45mm (45.46mm to be exact).

After finding the flange distance, subtract that from the lens focal length to find the distance to put the lens from the camera mount.

Step 3: Building the Lens

Now the lens needs to be built.

Make a tube (toilet roll, duct tape, ...) the length of the final distance calculated in the last step but if you are attaching it to an adapter make sure it fits and if the adapter lengthens the flange distance, take that into account.

Now attach the tube to the lens (duct tape).

Step 4: Finished and Example Photos

Slide the lens onto the adapter (or attach to camera).

Move the tube and lens forward and backward to focus.

Have fun!

Step 5: Taking It Further

You could make your lens better with many ideas, here is a lens I made previously with an interchangeable aperture.

As you can see I could have taken my time and made nicer apertures, but I didn't.

You could make a cardboard extension tube, lens cap, compound lens and anything you can think of!

Have fun making lenses.

PS Please vote for me in the photography tips and tricks contest!



    • Science of Cooking

      Science of Cooking
    • Pocket-Sized Contest

      Pocket-Sized Contest
    • Spotless Contest

      Spotless Contest

    We have a be nice policy.
    Please be positive and constructive.




    Great creation! Will for sure come in handy. I was thinking too the same principal you could be used if you got a mount for your camera body (a cheap ring mount to some other lens mount) and build onto it with a homemade lens to make it a bit more sturdy! none the less awesome idea!

    A set of bellows that cover the focal length of the lens would work for this project nicely. Just attach the lens to the end of the bellows and ta-da!

    Very interesting idea! The result is a sort of vintage, organic looking photo. Very creative!

    I thought the same thing :-)

    Not the same results as a $1000 100mm lens...