Monday, October 22, 2007
I am fascinated with all forms of imaging so for a while an infrared conversion of a point and shoot camera has been on my to do list. Early in October I was browsing Henry's Camera Surplus Store when I noticed that they had a 3meg pixel reconditioned Olympus point and shoot (P&S) on sale for $30. So I had my project. While not quite yet as the menu was only in Japanese and I don't understand the language. So back to Henry's to up grade to a 4 Mpixel C-4000 zoom had to lay out an additional $20.
Now the conversion. I wanted a camera that was sensitive enough to be handheld so I knew I had to replace the hot mirror (the little piece of glass in front of the sensor which reflects (filters out) most of the infrared and stops it reaching the sensor.
I researched some background on the disassembling of a c2000z here and here. As each camera is slightly different I had to play it by ear in a few places but it was mostly as advertised.
My original idea was to scrape the hot mirror coating off the filter. Unfortunately I used a abrasive that was too hard and I scratched the glass surface. I think next time it will work if I use steel wool (should be slightly softer then glass). So I had to order a custom cut watch crystal from a local watch repair place. Because the index of refraction of the mineral glass is higher then that of the original cover the thickness ordered was 2.5mm instead of the original 2.8mm.
In the mean while realizing the camera would be very myopic and could not focus to any where near infinity I put the camera back together without the glass sensor cover. What I did not realize was that how good the camera would be as a super macro camera. I am thinking of buying another one to use just in this mode.
Infrared Super Macro Myopic (no sensor cover glass)
I adapted my deep red infrared filter by lining the ring with foam weather stripping. I purchased the filter for a few dollars at the local camera show. I brought it to use on my 1953 Zeiss Contax IIIa.
Finally one week later $25 poorer the watch crystal came in. Much easier taking the camera apart the second time. Now it has no trouble focusing and still works in macro mode. Total cost for the project including the filter was less then $90.
Infrared Photograph of a Photographer Taking a Photograph of The Grand Bend Sunset
All the above shot were hand held without using the flash. The camera for maximum image quality is usually set at ISO 100. For best results it is best to do an in camera custom white balance using a white sheet of paper. This might not be necessary for all filter types. My filter still lets in a good deal of dark red so the true infrared is in the blue and green channels, a custom white balance is necessary to remove the dominant sensitivity to visible light in the red channel.
You can go here to see a Flickr slide show of my infrared work.