Webcam Telescope

If you're like me and collected all things new and digital during the 90's, then I can almost guarantee you have a bunch of old web-cams lying around doing nothing. The resolution on these things tends to be so bad that it's difficult to almost make out yourself when you're 'chatting' online with one of them. Despite all this, I was looking for a creative way to use my excess in web cam (I think I have around 6 or seven of them by now). About a year ago I lived in a high-rise flat in a place called Nove Butovice on the outskirts of Prague with a large nature preserve that sort of slopped down and away into the distance. While the winds that would blow in from it were wicked in the winter, when it was warm out it provided some pretty nice views of people picnicking, walking their dogs, and of the wildlife. It occurred to me that a telescope would be fun to have, but they were expensive for a casual interest that essentially amounts to people-watching.

So back to the web cams, I thought, "why not build a telescope?” Because of the nature of differences between lenss for different formats of film I figured I could build a web cam device that would provide pretty decent magnification using lenss for my 35mm camera that I already had lying around. It's a little bit hard to explain the specifics behind these 'mysterious differences' but suffice it to say that essentially you are cropping your field of view to a very small portion of an image, yet representing that very small section as a full frame. There's also something to do with pixel size, but I don't know how I'd go about explaining that and keep this pertinent. Rest assured that with even only an average length telephoto lens you can easily build a Web cam telescope that can read license plates from quite a distance.

What You'll Need

Wood - The whole thing will be mounted in a wooden box contraption. Get whatever type of wood you want, but remember you'll need to get something thick enough to put screws into the side of the sheets of wood you have.

Screws - Your pick.

Metal Bayonet Adaptor - This isn't a deal breaker, but generally pretty key. It will be difficult for you to mount the lens to the wood without a bayonet adaptor and without using an obscene amount of tape. Luckily these can be found fairly easily, and reputable camera repair shop should carry them. I got mine used for $15, and new they cost about $30, with screws.

Web cam - Any web cam will should do. I used one of those Logitech 'eyeball' web cams as I had one lying around. The important thing is you will need to get at the CCD element so make sure you can disassemble the thing.

Lens - Your pick again. This works with any format and any type of lens, (even magnifying lenss although they aren't so convenient).

First you'll need to measure out where you are going to cut up the wood. You will want to make a box in the end so cut appropriately. Then on your panel of wood that will comprise the front of the box, sketch out where the bayonet will be mounted.

Then proceed to drill out the center of the panel and mount the bayonet.





You'll then want to test your mount with a lens, just to see if there is enough space for the lens to slip in.



Now, feel free to disassemble your web cam.

This is the part we want. (NOTE: Don't you dare do this to your REAL digital camera. Savor this oppertunity as it should hopefully be the only time you get to handle the CCD element of a digtial camera directly.)

With some screws and PC board standoffs mount the CCD chip onto your back panel, (make sure it's centered first!).



Then go a head and finish your box, making sure to screw everything together tight. It should look a little bit like this:





And that's it, attach your lens and your all done!

So, now that you have it finished, it's time to check out the zoom ability. Here is a shot of the street across from my house with the web cam before modification using the regular lens it came built with.

Really, that's pretty wide. Not much detail either. Looks like a typical web cam shot. The images below however are from the same vantage point and although they aren't even visible on the image above, each of the images below is a shot through the converted web cam. You can read the license plate on the white ford across the street, see through the trees at a 'for rent' sign, and even pick out an American flag decal on a car parked at the bottom of the frame. Pretty cool huh? Hey! No peeping into bedrooms!

And that's that. Have fun!

UPDATE: Oops, I forgot a pretty critical step of the assembly. When you put the thing together you need to measure the distance between the CCD assembly and the lens. To do this, look on your SLR camera and find the film plane indicator. Then measure the distance from the film plane indicator to the bayonet, that's how must distance you need between your lens and your CCD. But don't cut your wood that length, you'll never get it right; give yourself an extra inch or so of wiggle room so that you can adjust it.

You'll also need to be careful that the CCD is parallel to the lens if you want to keep your image quality up. This of course, when working with wood and screws, can be difficult. But try your best, wiggle it around until you have image quality that you can live with and you feel satisfied with. Then have fun!