Create a camera obscura

Create a camera obscura

Justin Quinnell introduces us to his camera obscura kit

"Where is that"? As another class gasps at the inverted view of the outside world. It takes getting a teacher to run around outside, projected upside down on the screen in front of them to convince them it is a live image. No web cam or projector, just a 2500-year-old optical projection.

Image 1 Full projection

What is it?

The camera obscura (Latin for 'darkened room') is the earliest optical device and goes back over 2500 years. Originally images were projected through a small hole but from around 1500AD onwards, they began to use a lens.

Creating an obscura is cheap, easy and can be used at all levels to introduce aspects of art, science, history and technology.

I have been teaching photography and pinhole photography for over 20 years but over the past 5 or so years I have realised the increasing lack of 'wonder' within modern technology. However clever interactive smart boards and digital projectors are, I have never seen their use result in a gasp of amazement from a class of tech savvy primary children. Perhaps it is the lack of opportunity for understanding in our ever-increasing 'auto' world, which creates a barrier to comprehension.

Viewing a camera obscura projection does just this. Inspiring wonder should be the bedrock of education.

Creating a camera obscura is cheap and simple. By simply blacking out a room, positioning a lens and hanging up the projection sheet you can create a giant 2m x 2m inverted colour projection of the outside world 2500, years after Aristotle first wrote "WWW, that's CWWL!"

It can help teach history; science; art and optics in a single dynamic memorable fun filled lesson. The definitive contrast to modern digital imaging and projection.

Image 2 - Blackout

Obscuras work most effectively in a completely blacked out, light tight room and work in both sunny and overcast conditions. Blacking out a room can be done with pre cut cardboard, which can be quickly placed into position with Velcro tape.

Creating a scenario.

Before you show a projection, cover the lens with some card and light the room with a dim (red cycle) light to allow the students eyes to get used to the dark. Whilst their eyes adjust you can tell them all about how light works, how stone age men possibly first noticed inverted images in their caves and how the gaps in a leaf canopy have been projecting the image of the crescent moon onto the forest floor for millions of years, then, whip the card cover off the lens et voila! Instant wonder!

Initially you could get your students to attempt to draw the inverted projection by using a card frame and tracing paper held in a stand but there are many other experiments with light, which can be performed in a light tight room involving prisms, lasers, mirrors etc.

The instructions cover: Ancient Egypt and Ancient Greece, Isaac Newton and the shadow of a hair, pinhole projections, slot imagery, the use of concave mirrors, concave mirrors, prisms as well as looking at digital versus optical projections.

Image 3 - Full den

The Glenfrome 'Dark den'.

I have always been a fan of removing the idea that 'complex' subjects require older children to appreciate them, which is why I leapt at the opportunity of adapting the reception years outdoor den into an obscura.  The process took about 20 minutes to build and is used daily by the children in reception, especially by my 4 year old daughter Rosa.

Image 4 - Obscura and Rosa

Although a white sheet is currently hung in the den it works just as well with the children holding a sheet of white card to find the focal point and the area that their friends are jumping around outside, and more often than not trying to stand on their heads! Holding a board with - THIS IS UPSIDE DOWN written back to front also works well (although hopefully not too much of a hindrance to jolly phonics!)

Image 5 - upside down sign

Instructions on how to make the obscura can be found on my website or if you want to save yourself a trip to several shops, a kit with instructions can also be purchased. 2500 years of wonder for £1-00 a century!

Image 6 - Rosa and lens

Biography

Justin Quinnell is a freelance pinhole photographer and lecturer from Bristol in the UK. His website www.pinholephotography.org has information on creating camera obscuras and pinhole photography.

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