Other stuff to do with a destroyed modified digicam.

How to do the modification.

I've covered most of this on the IR webcam page in the standalone section, so here's a quick overview...

Safety First

If the camera you want to convert has a flash then there is a risk of electrocution!

Camera flashes operate at a high voltage (several hundred volts) which could in theory deliver a fatal electric shock. To make matters worse, the high voltage is still present when the camera is switched off, and even when the batteries are removed. If you still want to continue, be very careful. The capacitor that stores the charge for the flash is usually a large cylindrical object. Avoid touching the connections on this and any part of the circuitry that may be connected to them. It is not usually easy to identify what bits of circuitry are connected to the flash so it's better not to touch anything electrical in there.

Right that's got that out of the way, here's how I did it.

Obtain a cheap digital camera

I got mine from eBay, I'd suggest doing something similar if you're planning to do any of this yourself. The only things that really matter are that it MUST have an LCD viewfinder, a tripod fitting and a self timer. Here's a picture of mine before the modification.

Remove the lens

I did this by cutting around the little window in the front then breaking the glue that stopped the lens from coming unscrewed by squeezing it with pliers. Then the lens just unscrewed like a webcam one giving me a clear view of the CCD sensor.

Create a means to attach a new lens

An early introduction to extension tubes is needed here, later I'll explain what they're really meant for. Extension tubes are just tubes of metal with the correct fitting to screw a camera lens into one end and screw the tube into the camera body. Usually they have easy to grip contours and often there are mechanisms to operate things in the lens as the camera body would normally do. A typical extension tube looks like this.

This one is an M42 mount, which just means that it fits on cameras with an M42 lens mount. An M42 mount is a screw thread 42mm in diameter, but you don't really need to know that. It's used on old Practica cameras but the only bit of that we're interested in is the word old. Old camera equipment goes for peanuts on eBay.
Now back to making the lens mount on the camera. I did this by gluing an M42 extension tube to the front of my camera body. I chose a tube (by the way they normally come in sets with various lengths in) with approximately the right length to hold the lens as far from the CCD as it was from the film in the original camera. In case it matters to anyone, the glue I used was Areldite Rapid.

Add a lens

As you've read above, I used an M42 extension tube to make the lens mount. This means any M42 lens will fit my camera. Here's a picture of it with the standard 50mm lens fitted.

Because the CCD is much smaller than the film the lens was designed for, the image is much larger than it should be. For macro photography you don't really need to worry about this.

SLR Lens Basics

SLR camera lenses have a focus control and an iris or aperture control. The focus control moves the lenses around to focus on near or far subjects. The aperture control varies the effective diameter of the lens. A bigger lens takes in more light but is harder to focus, it has what's known as a small depth of field. Closing the aperture makes focusing easier but less light is taken in, meaning you'll need more light on the subject or a longer exposure time. Longer exposure times make camera (or subject) movement blur the image more. Many lenses have an Auto/Manual control for the iris, for a modified camera this should be kept in the manual position as the camera doesn't have the ability to control it.

The Colours Look All Wrong

Fact of life I'm afraid. When the lens is removed the IR filter is removed with it, this makes the colours look wrong. A filter to correct the problem is available, it's called a "Hot Mirror" but they're expensive and very rarely appear on eBay. Another way to correct this is to light sources with little or no IR, such as fluorescent lights. I now have an angle poise lamp with a fluorescent bulb which I intend to use for this but at the time of taking the samples below, a flashlight was the best I could manage.

Getting up Close

Have a twiddle with the focus ring on an SLR camera or your newly modified camera and you'll notice that to focus on something close, the lens moves further from the camera. This is what extension tubes are really meant for, to move the lens further from the camera. By doing this it allows the camera to be focussed on really close objects. The longer the extension tube, the closer you can get. There is a device known as an extension bellows which allows the lens to be moved smoothly away from the camera body instead of in steps as with extension tubes. These are fairly rare and get quite expensive, even on eBay. You'll find that the closer you get the more critical the focus becomes. You can get around this to some point by closing the iris on the lens but this will require more light.
Holding the camera still enough to see anything is virtually impossible. this is where the tripod fitting comes in. Again, try eBay for the tripod as a decent new one costs a fortune. You'll probably find that even with the camera mounted as securely as possible, pressing the fire button shakes it. I get around this by using the self timer on the camera. If you're taking pictures of things that move (I like insects) you need a lot of luck, and a lot of memory in the camera. It's not rare for me to take more than 100 pictures to get one I like. This is where film would have been expensive.

Samples


A Grasshopper. You can see the upturned glass used to keep it on the desk. Lined white paper helps to focus the camera.



This subject held perfectly still for me.



The face of a Woodlouse. The IR has given this a strange red appearance. Note how little of the image is actually in focus.



A harvestman spider and a closeup of one leg. I took this in infrared using exposed negatives as a filter. Notice how transparent the body is in IR.



A live housefly. This wouldn't stay still for long.



A moth, I have no idea what type but it had nice eyelashes. This shows how close I can get with the modified camera.



Finally two different spiders, this is probably the last view some insects see. Again you can see that one on the left is almost transparent because of the missing IR filter.

YouTube link to a spider movie made using a webcam modified similar to the camera above. Notice the large array of eyes.

Other Stuff.

The Infrared Webcam Page

The temperature in Nottingham

My Chess Race animation on YouTube (Opens in a new window)