Introduction: Bad Rainbows Go to Prism!

Hi All,

If you think your life could use a little more color, look no further. This photography Instructable employs basic principles you learned in grade school and both the process and the results are a lot of fun.

It can be done at home without too much equipment, all of which is reusable and most of which can be improvised.

To summarize, you will darken a room to only allow in a small shaft of sunlight. This light will be refracted with a prism, and then you can do whatever you want with it. I was able to take some beautiful photos using a second crystal to further scatter the light and those are what I will share with you today.

I won't lie to you, there is significant prep work involved and the results you get will be dependent on how you handle it. But do you want some amazing pics with a minimum of post processing? I sure do. Let's get started.

*You probably know all about refraction from science class in school but in case you want to refresh, here is the Wikipedia Entry.


You will need:

  1. A sunny day! If you don't have one, let me know and I will mail you one from here in Miami.
  2. A room with a window facing east or west.
  3. Something to cover said window.
  4. Some way to secure your window covers, thumbtacks work well.
  5. A prism! I used THIS ONE. It's $11.80 on Amazon, but any one of decent quality will work. I recommend you stick to glass if possible.
  6. A SECOND CRYSTAL to scatter your new rainbow. A bargain at $10.89. Once again, if you want to use a different one that's totally OK, but I find glass is better than acrylic.
  7. A tripod, or some kind of stand to hold your prism. The first time I did this I used an inspection clamp and a stack of books. Some cheap clamps and some zip ties and you're in business.
  8. A white surface to catch your colors. I happen to have had white floor tiles but paper or poster board will work.
  9. A camera. I bet you usually have one in your pocket.

Step 1: Step 1: Darken the Room

So once you've found your sunny east or west facing room, you want to make it as dark as possible. When you are done, you want a single shaft of sunlight coming in. So you will need a rectangular hole in your cover about 1 foot by 4 inches (30 by 10cm). This sunbeam will be your new best friend. And everybody loves a sunbeam, just ask Morris.

For my own self, I have tried this using spare bed sheets, cardboard and aluminum foil. They all have their good and bad points. Bed sheets and thumbtacks were the easiest, but they let in the most light. Foil works well but is difficult to reuse.

If you start to feel like you're in a crack house, you're on the right track.

Something to consider, you have a time hack! If your windows face east your best light will be in the morning. If they face west, then your best light will be in the late afternoon. Regardless, the angle of the sun will be constantly changing with respect to your window and at some point you simply won't have the light you need and you will have to try again tomorrow.

You want to set up early and try to maximize your appropriate angled light, maybe even installing your covers the day before if you are going with light from the east.

Step 2: Step 2: Catch the Rainbow

Now for the fun part! With whatever you are using to hold your prism, you want to set it up so that it (the prism) interrupts the beam of light that you created in the last step. This is pretty straightforward, but you will want to be able to rotate the prism in order to get the best rainbow out of it.

You will also notice very quickly that there is a relationship between the angle of the light coming in compared to the surface it is landing on. A nice low angle will give you a nice wide, coherent rainbow. And don't get too comfortable, you will have to make small adjustments as the angle of light changes. I found a matte white surface to be the best for photos so now is the time to put down your paper or poster board.

Step 3: Step 3: Deconstruct the Rainbow!

So this is the best part, taking your amazing photos! For camera settings, I would recommend lowering your exposure and resisting the urge to over saturate in high dynamic range mode (HDR). Really though, it's up to you.

Move your crystal around. Play with the angles. Rotate your prism. Pet your pet.

But- as a strategy, it is better to take all the photos now, and then edit or share them later. You WILL run out of time. Facetagramsnaptube can wait.

Step 4: Step 4: Shine on You Crazy Diamond!

So now, have fun with it! By now all your friends are greener than the green in your rainbow with envy but don't stop!

What else can you do with this, now that you have the know-how?

Try for perfect symmetry? Be careful. Step on no pets. Like Tacocat.

How about exploring different textures? Have a potato.

Some sinister portraiture? Yes Please.

Wanna make a shout out for Pride Month? Go for it.

Please feel free to ask any questions you have, I'll do my best to help.

Also - This process has TONS of room for improvement so if you come up with any refinements or if any of you awesome possums create something you're really proud of I am sure we would all love to see it. Leave a comment or consider writing up your own instructable.

*Please note that these pictures were taken using my cell phone and the native camera app. I know there is already a ton of image correction software involved but my goal is always to try and get a pic of how something actually looks. For this reason, I am not a big fan of filters or super HDR saturation but this is your project now and please feel free to make it your own.

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