How To Make A Homemade Projector With A Mirror

by Matthew David | Updated: 09/14/2023

How To Make A Homemade Projector With A Mirror

Have you ever wanted to watch a movie on a big screen, but don’t have a projector? With a few basic supplies and some creativity, you can easily build your own homemade projector in no time!

In this simple, step-by-step guide, you’ll learn how to make a smartphone projector using a cardboard box and a mirror. We’ll cover everything from gathering materials to setting up the mirror, inserting the lens, and adjusting for the best picture.

Follow along to create a fun DIY projector for cozy movie nights, tracing images, or making unique light effects. Let’s get started on this creative endeavor!

Why Make a Homemade Projector?

Before we dive into the how-to, let’s look at why you may want to make your own DIY projector in the first place. Here are some of the benefits:

History of Homemade Projectors

Before shopping malls were filled with the latest high-tech gadgets, people had to get creative to make their own entertainment. Homemade projectors have been around for centuries.

The basic technique traces back to the camera obscura, which uses a small hole or lens to project an inverted image onto a surface. Renaissance artists even used this method to trace scenes accurately!

Early homemade projectors worked the same way, using light sources like candles or sunlight focused through a lens. The most basic projectors could be made from everyday objects in just a few minutes.

While modern projectors are much more advanced, the DIY method still works! With some simple components, you can build your own fun projection device quite easily.

Materials Needed

To build your homemade smartphone projector, you’ll need:

Optional but useful supplies include black paint, a ruler, and a precision knife. Having these on hand will make some steps easier and give you a more polished finished product.

The smartphone provides the display, while the magnifying lens enlarges and projects the image. The mirror bounces the image towards the wall to display right-side up. Simple!

For the box, you want one with a manageable size – large enough to fit your components but compact for portability. A rectangular shoebox is the perfect DIY projector base.

Preparing the Cardboard Box

The first step is selecting a box to house your projector. A rectangular shoebox is ideal, as it’s compact but wide enough to fit your phone.

Once you’ve chosen a box, use a craft knife or scissors to cut out one of the narrow side panels. Save this panel, as you’ll need it later for mounting the lens.

Next, darken the inside of the box to prevent light leakage. You can paint the interior black, or glue black construction paper along the walls and base. Ensure no external light can enter or reflect inside.

The black backing absorbs stray light, rather than letting it bounce around and diminish the projected image. A matte finish is best to avoid reflections.

Seal up any gaps, holes or leaks thoroughly to achieve nice dark conditions inside your homemade projector. No pesky ambient light allowed!

Inserting the Magnifying Glass/Lens

Now it’s time to install the lens. Take the panel you removed earlier and trace the magnifying glass or lens in the center.

Carefully cut out the circle slightly smaller than your tracing so the lens fits snugly. Insert the lens into the hole with the curved side facing inwards.

Secure the lens with tape or glue, then reinforce the panel by wrapping a strip of black paper around the edges. This creates a flat lens panel that can slide inside the box.

The magnifying glass serves as a simple convex lens to enlarge the smartphone’s screen image and project it onto the wall.

You want a lens with some optical power, but not too much distortion. Shoot for 2x-3x magnification for a nicely enlarged picture.

Position the lens precisely in the center of its panel cutout. Securing it firmly in place helps maintain clear focus.

Slide this detachable lens panel into the main box, being careful not to smudge or touch the lens. Keep it cleanly in place to get a sharp projected image later on.

Setting up the Mirror

On the opposite end of the box from the lens, position the mirror at a 45 degree angle. You can use a protractor to get the perfect angle.

Adjust the mirror so when you look down at it, you can see the lens panel. The mirror reflects and redirects the image right-side up.

The smartphone will sit above the mirror and beam light down onto it. By bouncing this light at an angle up to the lens, the mirror tricks your eyes into seeing the image correctly oriented, not flipped upside-down.

Play around with gently tilting the mirror forward and back until the reflection aligns perfectly with your lens. You want optimal light transfer for the brightest, clearest picture.

Creating a Slot for the Smartphone

To hold your phone, trace its screen dimensions on the box’s lid. Cut out a slot slightly smaller so the phone can rest atop the opening.

Make sure the phone sits above the mirror and projects straight out through the lens panel. You may need to prop or angle it so the screen faces directly down.

The phone slot should be snug, with no wiggle room. Place it as close to the mirror as possible, but don’t let it slip down into the box! That will block the projected light path.

Center the phone slot precisely above the mirror’s reflection point. Aligning these optical components is key for a properly projected image.

Final Assembly and Adjustments

You’re nearly there! Insert the lens panel and secure all parts tightly with tape or glue. Check for any light leaks and seal them up.

Place your phone in the slot and test the projection on the wall. Slowly move the lens panel back and forth to optimize the focus.

You may also need to adjust the mirror angle and projection distance from the wall to achieve a clear, sharp image. Have fun dialing it all in!

At this point, your DIY projector is essentially complete. But like any good craftsman, you’ll want to tinker, tweak, and adjust to maximize performance.

Little details like tightening loose joints, evening out the mirror angle, and securing the phone slot will enhance the projection results. Take your time to finesse and perfect your homemade masterpiece.

The distance between the lens and wall, and between the projector box and wall, also make a big difference. Zooming in and out will help sharpen the picture.

Projection Surface Options

A blank white wall is the classic go-to projection surface, but it’s not your only option when using a homemade projector. Get creative with different backdrops to really make your projected image pop!

Here are some surfaces to try:

Get creative with workspace backdrops too. Project conference calls or webinars straight onto the wall for easy viewing!

Getting the Best Results

For ideal projection, use your DIY smartphone projector in a dark room onto a blank white wall or surface.

Maximize your phone’s screen brightness, and try closing curtains or blinds to minimize ambient light. Position the projector closer to or further from the wall until the image is sharp.

Avoid blurry or distorted pictures by double checking the lens angle and placement. If the image is reversed or upside down, gently tweak the mirror position.

Here are some other tips for optimizing projection quality:

Troubleshooting Common Issues

Don’t panic if your first projections aren’t picture perfect. Tweak and troubleshoot your projector with these tips:

Blurry or distorted image:

Image is faint:

Can’t get image right-side up:

Image not centered on projection surface:

Smartphone overheating:

With some trial and error, you’ll get the hang of tweaking your homemade projector to work its magic. Have fun experimenting and learning as you go!

Safety Tips

Like any DIY electronics project, it helps to keep safety in mind when designing your smartphone projector:

With some simple precautions, you can make the projector building process smooth and hazard-free for people of all ages to enjoy.

Additional Tips and Tricks

Beyond movie nights, there are endless creative uses for your homemade projector. Trace images by projecting onto paper and outlining the shapes.

Or, add unique lighting effects to your photography by projecting patterns and images onto subjects. It’s also a fun, screen-free activity for kids.

Use your imagination to come up with innovative ways to use this classic DIY projector. The possibilities are endless!

Here are some other ways to put your new projector skills to use:

Upgrade Options

Once you’ve mastered the basics, consider upgrades and add-ons to enhance your homemade projector:

Whether you want to boost performance or just personalize the look, the possibilities for enhancements and mods are endless. Add your own flair to this homemade classic!

Hosting DIY Movie Nights

Once your smartphone projector is ready for its big premiere, it’s time to host an unforgettable movie night!

To build the perfect home theater environment:

With a DIY concession stand, festive decor, and a stellar film lineup, your living room will transform into a lively cinema. Get the popcorn popping – it’s showtime!


Constructing your own smartphone projector is an enjoyable, budget-friendly craft project. With just a shoebox, magnifying glass, mirror and phone, you can set up a DIY movie projector in under an hour.

Follow the step-by-step instructions to assemble the simple components. Adjust the lens distance, mirror angle, and projection surface for the clearest picture.

From optimizing the image to troubleshooting issues, this guide covers all the ins and outs of making your own projector. Take advantage of this fun DIY option for custom home entertainment on a dime.

Then grab some popcorn and get ready to watch your favorite flicks on the big screen! Making your own projector is a great way to repurpose household items and unleash your creativity.