How to build a camera obscura in your own house

Our readers seemed fascinated by the recent art installation of a large camera obscura in New York City's Madison Square Park. But what if you can't get to the Big Apple in time to see it? It turns out it's pretty easy to make one yourself, and transform a room of your house into your very own camera obscura, using this tutorial by Photojojo.

All you really need to make a camera obscura is a room with a window. Ideally, there should just be a single window with a view that you like, and a blank opposite wall. The short version of the tutorial is that you black out the window with black poster board, apart from a single lens opening, which then projects an inverted image on the back wall.

If you have any extra windows or light leaks, you have to block those too, and if you don't have a plain white wall, you can always hang a sheet. The process of light-proofing a room should be familiar to anyone who's attempted to set up a home darkroom, but at least a camera obscura is a bit more forgiving on the occasional smidge of illumination leaking in.

The interesting part of pulling this all together is how to create the lens. Traditionally, any sort of small opening will work. Photojojo recommends using the lens from a flashlight, or else cutting aluminum foil circles of various sizes so as to create different apertures. As with a normal photograph, a larger aperture means more light comes in and a brighter, but softer image.

The "Topsy-Turvy" art installation in New York isn't the only large scale camera obscura that you can see. Visitors to San Francisco can drop by the permanent camera obscura on Cliff House by Ocean Beach. Or, if making an entire room into a pinhole camera is too big for you, you can always make a small, box sized version.