Introduction: Build a Smartphone Projector With a Shoebox

Picture of Build a Smartphone Projector With a Shoebox

Did you know you can turn an old shoebox and some office supplies into a Smartphone Projector? Yes you can! It is a fun, simple and easy physics experiment that you could do at home. Learn and observe how light


The project has been around the net for a long time, but here's a brief and detailed tutorial I made for everyone. (Most of my new videos will be made as brief and detailed as possible. Enjoy!)

Please do check my new YT channel:TechBuilder

If you like my past 4 episodes, feel to:Subscribe

I'm back guys! During my very long absence of not posting projects here in instructables, I was shooting and compiling lots and lots of video tutorials to preserve the continuity of my new channel. Every week, I'll be posting new and random projects. So most of the Instructable tutorials that I will be posting, will start to have a video tutorial attached to it. Please do subscribe, if ever you are interested. Thank you! ^_^

Step 1: ​How Projectors Work

Picture of ​How Projectors Work

There are two major types of projectors in use as of this writing (things change pretty fast in the field). Projectors come with many features, strengths, or weaknesses, but most will run on either LCD or DLP technology. LCD is the older technology, but this does not mean that it is becoming obsolete by any means. LCD stands for Liquid Crystal Display. The way this places an image on a screen is fascinating and not nearly as complex as you might imagine. A bulb is set up to shine a fairly powerful light through a prism. The prism splits the light into its component colors and these are sent through small LCD screens. The screens themselves are sent signals to allow just so much of the light through at specific pixel locations. The light is then beamed through a lens onto a screen where the images can be seen by the human eye. DLP, or Digital Light Processing is a bit more complex. This time the light is shined through a spinning color wheel onto a chip that is mounted with hundreds of thousands of tiny mirrors. The mirrors are turned off or on by electronic impulses according to the need for the color at that moment. Even though only one color is shown at a time, one color follows another so quickly that the primary colors seem to blend into the appropriate color. The image appears to be constantly lit, when in fact small parts of it are constantly flickering. This technology was developed by Texas Instruments and is based on an older technology that was used for color television in the 1950s. Knowing the difference between these two types of projectors can be important, as LCD is considered better for static or high-contrast images. DLP, with its more vivid colors, is thought to be better for video. Some DLP projectors, have been known to manifest a rainbow effect. This can happen when white objects move on a dark background. Small shadows of red, blue, or green may be seen. Most modern DLP projectors have overcome this problem with multiple chips and higher rotation rates for the color wheel. So to what uses can we put these amazing machines?


This is not mine. This article was taken directly from: (source)

Step 2: Thing You'll Need

Picture of Thing You'll Need


- Magnifying Lens

- Foam board

- Smartphone

- Gluesticks

- PVA Glue

- Shoebox



- Hobby Knife (XACTO)

- Hot Gluegun

- Cutter Knife

- Hacksaw

- Ruler

Step 3: Remove the Handle

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Carefully use your hacksaw to cut off the handle of the magnifying glass.

Step 4: Reinforcement

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Reinforce the box by gluing the flaps and corners of the box. This prevents it from wiggling.

Step 5: Let It Dry

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Don't get too excited. Let it dry for a few minutes.

Step 6: Lens Placement

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Position your box in an upright position. Place your magnifying lens on top then center it. Use a pencil to trace the cut line.

Step 7: Cutting the Perfect Round Hole

Picture of Cutting the Perfect Round Hole

Here's a simple trick that I used all the time. If you are too OC, you can use an XACTO knife at the other end of a compass for cutting a perfect and round hole.

Step 8: Pop!

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Push it, pop it!

- This is satisfying! Feels as if you were popping a bubble wrap. :)

Step 9: Position Your Lens

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Position your lens before gluing the it in place.

Step 10: Glue the Lens in Place

Picture of Glue the Lens in Place

Step 11: Cut Off the Protrusion

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When you put the lid back on, the lid could block a portion of your lens (depending on the size of your lens or box). Use your precious cut out as a stencil then carefully slice off the excess cardboard that's blocking your lens.

Step 12: Build the Phone Stand

Picture of Build the Phone Stand

Build a phone stand using a foam board. Make sure it's perpendicular from the base to avoid image distortion.

Step 13: Tape Your Phone

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Use a double sided padding tape to mount your phone on the stand.

Step 14: Set Your Phone

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Set your phone to the highest brightness:

Simple, more light results to a brighter projection.

Don't forget to lock the screen:

The lens inverts the light source (your phone's LCD) to the projected image. This means you'll have to position your phone's screen in a topsy-turvy position in order to prevent it from auto rotating. Go set the lock-screen setting and disable the auto rotate.

Flip The Image: (optional)

Download an app that flips the orientation of the image.

Step 15: Adjust Your Projector

Picture of Adjust Your Projector

Like all projectors, this one needs to be calibrated too. Position your phone at the very end of the box then slowly move it closer to the lens, you will notice that the image will turn sharper/ softer. Move it back and forth until you get the sharpest projection.

Step 16: Turn Off the Lights - Watch in the Dark

Picture of Turn Off the Lights - Watch in the Dark

Turn off your lights, wait for it to get dark then Enjoy!


Please do check my new YT channel: TechBuilder
If you like my past 4 episodes, feel to: Subscribe

I'm back guys! During my very long absence of not posting projects here in instructables, I was shooting and compiling lots and lots of video tutorials to preserve the continuity of my new channel. Every week, I'll be posting new and random projects.

Step 17: ​So Stay Tuned! There's More to Come!

TechBuilder Season #1 Includes:

- Minty Microphone Preamp

- Ultraportable Spud Canon! (This one's a killer. Promise! It's made from a stubby waterjug!)

- PVC Camera Slider

- Supercharge A Cheap Mini China RC Car (30,000rpm motor mod, Bluetooth Phone Control, LiPo, 30A ESC)

- Studio LED Lighting Panel (shown in the last few second of my projector video tutorial)

- Make A Cotton Candy Machine (using kitchen supplies)

- All You Have to Know About Greenscreening

- Funny Tissue Paper Dispenser Hat


This is the reason why I've been gone for so long. :)


PedroHenriqueGuida (author)2015-07-31

I have made one for me, it worked well, I also made a modification with a little mirror to get the image not flipped horizontally.

Hey can u plz direct message me on my email( ) even i want to flip my image coz its latterally inverted , and even i have a query regarding brightness of the image , plz plz plz message me on my email

hey i dont know who are you but plzz tell me which mm glass did you used i tried it with 75mm of glass but it was not working plzz help me out thanxx for your prisious time

ASCAS (author)2015-07-09

Next Project: "Car Horn Rigged Alarm Clock"


Any insights or suggestions on what you guys want to see on my next instructables/ YT video tutorial? :)

oggol (author)ASCAS2015-07-19

My alarm clock causes an earth quake.

kevin_28 (author)ASCAS2015-07-12

Pre ang galing mo idol na kita

ASCAS (author)kevin_282015-07-13

Salamat tol! ^_^

kevin_28 (author)ASCAS2015-07-12

Tanong kulang san ka nakabili ng arduino

ASCAS (author)kevin_282015-07-13

Yung iba napanalunan ko sa contest dito sa instructables. Yung mga clone ko na Arduino nabili ko lang dito sa pinas, sa E-gizmo at sa Alexan. May website sila sakaling naghahanap ka, igoogle mo na lang. :)

kunalnc17 (author)ASCAS2015-07-11

i want to see something which is practical for our dailly life

or atleast sometimes

and what is use full for a 11 year old child like me

ASCAS (author)kunalnc172015-07-11

That's nice! Half of my upcoming video tutorials will be about building practical projects, the other half is just building projects for fun (ones listed in step #17). The practical ones are about making projects related to renewable energy (solar charge controller circuit, complete combustion stove burner, wind turbine, etc...). They aren't for young ones though. Do you have any suggestions that you want to add to my list?

soumitraseth (author)2017-08-17

It`s Very Very Good IDEA. Thank ALLL

Vishal262001 (author)2017-03-24

What should be the magnification of the lens? Many peoples asked you... But you didn't respond to it... Mail on me :-

pschlesinger made it! (author)2016-09-03

easy to make

Ashishb51 (author)2016-08-22

Great Project, thinking of preparing of my own but like to know, some technical details for magnifying glass to use.

what type of Magnifying Lens to use, i mean Biconvex or something else.
whats should be the Diameter & Thickness of lens,
whats the magnification power i.e. 3x, 5x, 10x, etc.

Kindly reply, so that i can buy the magnifying glass accordingly & try to prepare it for myself sooooooooon.


petepher (author)2016-08-01

nice one.

supersabba (author)2016-07-23

which side do you put the magnifier lens? i mean.. is it relevant? or does one side enlarge the image and the other restrain the image?

kroedel (author)2016-07-21

This looks awesome! I was wondering if you have come up with an alternate way of holding the phone to the foam insert (aside from double-faced tape)--maybe something less permanent for those of us who are a bit iffy about ruining their phone cases. Thanks!

ShackledFreedom (author)kroedel2016-07-22

Bend some wire and tape the wire to the display. Let the wire hold the phone in place

Abe Sam (author)2016-07-21

I was wondering how you'd deal with the inverted image... great idea to lock the phone to avoid using a second lens.

anant kumar (author)2016-07-09

I used 200 mm lens but the projected screen was very less. how can I make it bigger?

Fathomlis (author)2016-04-12

Really nice project...

Cristian Jay M.T (author)2016-03-30

Hi Angelo! I'm 16 my interest is cooking food but the same time i'm inspired to do things like yours, recently i made this projector and theres a problem, i know this case is common but my projector when i try it became blurry, and only light youll see, What is supposed to be the problem?. Please help as soon as you can. And reply asap. Thanks Angelo!

vardaan1234 made it! (author)2016-02-29

made it but it is not bright and even colours are not identical

raammv (author)2016-02-28

I bought a magnifying glass from amazon " .

When I try to project it I only get a flash of white light, image is not projected at all. Is there any special type of lens with specification has to be bought to obtain good quality projection with sharpness ? If so suggest me from amazon link.

sajalgupta (author)2016-02-13

i made it but ,i try three glass 1st was the bigger 2nd was smaller than 1st and 3rd which i fix was .

1 one need long distance ; 2 one needed bit smaller distance; 3 one need the smallest distance to fit in the box

and you could make it by using small magnifying glass

your follower

Clark SicnarfD (author)2016-02-09

i just did what did you do but the i can't see any image or playing a video it only blur lights, can u please hemp me its a physics project in my school

monster mrinal (author)2016-01-16

tell me all the parts did you use

monster mrinal (author)2016-01-16

hey bro i tried it but unfortunately it was not working can you tell me which mm of glass did you used i tried it with 75mm of glass but it was not working plzz give some of your prisious time to this comment and help me out

anand8025 (author)2015-12-16

which Lance are perfect for this project. i face many

problem like side images are bluer, color are not bright, please give me suggaction

teddyelsa made it! (author)2015-12-12

I did in a bit different way

SingularityX (author)2015-12-03

Do lens need to be the same size or larger than display to project whole display or can they be smaller?

JohnD221 (author)2015-11-29

it works, and i found an old piece of black felt to cut up and put inside the shoebox. However even at max brightness the image is simply too dim to be enjoyable (my phone outputs around 450cd/m^2 of light at max)

amujtaba3 (author)2015-11-14

what if we use led in the box

lorik.tahiri (author)2015-11-13

Hey, I made one like in the video in YouTube, but when i play something It doesn't show anything only blurred light, why??

sushantm2 (author)2015-11-07

What if we use a screen enlarger glass instead of magnifying glass so that we can get a square projection instead of round

Khizami (author)2015-11-04

thanks for the tutorial. I made it, but my results is always blurry image at the wall. I use 2 magnifying glass and then reflect the image with mirror, the results is blurry. is this about the lens?

Fission_Chips (author)2015-10-23

Dang, this is awesome! Nice job!

Ti patron (author)2015-10-21

How many mm is the magnifiyer lens

hahmad15 (author)2015-09-24

Made it

hahmad15 (author)2015-09-24

Haha Finally made it and instead of using a Magnifying Glass i used an old camera lens.
Works much better.
And one more thing
I used Black paper on the inside of the box to reduce the interference caused by the reflected light.
If you can't find black paper just like i couldn't just print a black image through printer and if it doesn't seem black then print twice on one paper.

Mua Anh SaiR (author)2015-09-20

Kính 90mm phải không cậu

Mua Anh SaiR (author)2015-09-20

Kính 90mm phải không cậu

Mua Anh SaiR (author)2015-09-20

Ban xài kính 90mm phải không?

Blackmumba (author)2015-09-17

Hi Ascas..I wanna try with my tablet, is there any calculation for choose what size of magnifying glass? i already experiment with 50mm magnifying glass but the focus is not good & got little blur, what should i do?

Keepsilentpol (author)2015-08-31


ronald laureta made it! (author)2015-07-12

yeah :D

ASCAS (author)ronald laureta2015-08-06


ASCAS (author)ronald laureta2015-07-12

Cool! :)

deba168 (author)2015-07-14

Simple and useful :)

About This Instructable




Bio: Hi I'm Angelo! I am a 18 y/o college sophomore taking my majors in BS-ECE at the DLSU. I use my course as ... More »
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