About & Pics


Prism HD is an inspiring exploration of real light shining through glass prisms and splitting into natural rainbows beneath your fingers. Interact with a variety of beautiful scenes, or create your own. Completely accurate in math and physics, you will be amazed at the feel of life in the light exploding from just a few simple prisms.

* Debuted at the Future Canvas 2 iPad art exhibit in San Francisco.

* Featured on the Atmospheric Optics Picture of the Day:
- "Prism HD is an iPad/iPhone App combining optics, accuracy and beauty.

* As seen on Wired.com:
- "There is a certain beauty in manipulating theoretical light and angles
of refraction and watching what happens"

* Also featured on KRON TV San Francisco

* Used as inspiration by professional artists and architects.


Prism HD uses sophisticated ultra-fast ray-casting to simulate tens of thousands of individual rays of light as they pass through a variety of colored or clear glass prisms. As you move and rotate the prisms and the light-source, the light reacts instantly to your touch, sending showers of beams across the screen. The beams combine and split in a fantastic array of natural rainbow patterns that you will recognize from the real world around you, but have never been able to interact with freely before. The result is an accurate simulation of the natural world with a surprisingly emotional power.


* Simple controls.
* 13 beautiful pre-set scenes.
* Every scene can be easily customized.
* Fully multi-touch.
* Tuned for all devices:
from iPod Touch to iPad 3, including Retina support and iPhone 5.
* Regular prisms: triangles, squares pentagons, etc.
* Star-shaped prisms with any number of points.
* Perfectly circular prisms, which accurately simulate drops of water.
* Each prism's shape and color can be easily changed.
* Simple control of optical properties like Index of Refraction and Dispersion.
* Written in 100% Objective-C, C++, and OpenGL for maximum performance.

* Many natural phenomena are accurately reproduced:
** Refraction, Dispersion, and Partial Transmission
** Snell's Law and Total Internal Reflection
** Caustic Reflections
(Have you ever noticed the curved reflections inside a coffee cup ?)
** Natural Rainbows are easily illustrated using a circular prism
** Accurately shows real-world optics behind atmospheric halos such as Sundogs.


Hundreds of thousands of individual rays of light are simulated each second.

Every ray obeys three simple laws of optics:

1. Refraction:
Light bends as it passes from one medium to another.

2. Dispersion:
Blue light 'refracts' more than red light.

3. Transmission and Reflection:
When light passes from one medium to another,
some of it passes through and some is reflected.

When these simple laws of nature are combined in a powerful computer such as an iPad,
the experience is captivating and beautiful.

 $1.99 in iOS App Store


Prism HD screenshot 1Prism HD screenshot 2Prism HD screenshot 3Prism HD screenshot 4Prism HD screenshot 5

Version History

Launched May 26, 2011 (over 7 years ago).

Releasing new versions every about 1 month, on average.

Oct 10
Version 1.20

thanks for all your great suggestions !
we're incorporating them as fast as possible,
keep them coming !

Sep 20
Version 1.19

Minor Refresher Release for iOS 6.

* Small changes for iOS 6.
* Fixed bug where prisms or the light-source could sometimes get stuck near the top of the screen.
* Fixed bug where start-shaped prisms sometimes had no width!

A larger update is in the works,
including prettier prisms,
support for landscape mode (and video),
and more.

Keep the suggestions coming
and as always, thank you for the comments !

If you have questions or an experience to share about Prism HD,
please visit http://appliedthaumaturgics.com/prism .

Apr 23
Version 1.18

* Now you can easily save images to the camera roll - just tap the button in the upper left. Only the prisms and light are saved, not the buttons and controls.

Mar 26
Version 1.17

* Bugfix for iPad Retina Support
- when the device finally dropped it turned out there was a bug in iOS which made retina support not work. but we've managed to work around the issue!

Mar 17
Version 1.16

* Updated with retina buttons.

Feb 27
Version 1.15

Minor Update:

* Improved controls for adjusting the size of prisms.

* Improved controls for grid selection.

* Improved visibility of grid resolutions.

* More convenient placement of pop-up control panels.

* Other cosmetic improvements.

Feb 12
Version 1.14

A much-awaited update !
Many thanks for everyone for all the suggestions and encouragement!

This release includes a new "snap-to-grid" mode with intelligent angle-snapping as well. Five grid resolutions are supplied, from very coarse to very fine, as well as both square and triangular grids. With grid-snapping, it's easy and fun to set up more complex geometric scenes.

We've added a new preset scene which demonstrates something amazing - a single beam of light being split into a rainbow and then re-combined back into the same white beam, over and over. This is done without lenses!

We added a new "Rate It!" button which takes you straight to the App Store's page for rating an app, so all you lurkers who love the app but haven't had the time to give it five stars, here's your chance!

And as usual, miscellaneous minor bug-fixes.

Oct 11
Version 1.13

support for iOS 3.1.3

Sep 21
Version 1.12

Small bugfix for an occasional crash in "More apps by us".

Sep 13
Version 1.11

* First Release!
After many months of feature-polishing and bug-testing, it's finally ready!

Sep 06
Version 1.10

this release is mostly about polish and usability,
but also includes a few new exciting features:

* true circular prisms
- these are a whole new ballgame in terms of coolness.

* new settings panel gives you control over:
- index of refraction
- amount of rainbow-ness (the cauchy coefficient)
- attenuation

* many UI improvements

* help screen

* minor bug fixes

Jun 09
Version 1.2

Now includes preset scenes !
Ten scenes have been included to illuminate the range of possibilities with Prisms and Light. You can modify each scene as much as you like, and reset it at any point.

Jun 03
Version 1.1

minor update:

* reset stage button

May 26
Version 1.0

Previous 3 versions

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