300D: In December 2004, I completed a modification of the original Canon Digital Rebel (300D) to remove its IR Cut filter. My web pages that detail the procedure are located HERE. The modified camera has performed well for me since then with no problems at all. You can see a gallery of astro images taken with the modified camera HERE. Some daytime infrared images are HERE.
450D: In April 2008, I completed a modification of the Canon Digital Rebel XSi (450D) to remove its IR Cut filter and a detailed procedure follows. Removal of the filter allows for a great increase in sensitivity to the color red and the H-Alpha wavelength important for deep sky imaging. Instead of installing a clear optical glass to replace the original Canon IR Cut filter as I had done for the 300D modification, I installed a Baader "DSLR Correcting Filter" which is a much milder UV-IR-Cut filter that allows the H-Alpha wavelength to pass for deep sky, but blocks higher infrared wavelengths that cause poor focus and bloated stars with refractor telescopes and camera lenses. This filter still allows the 450D to be used with an infrared pass filter, such as the HOYA R72, to take daytime infrared images with focusing via the live-view feature. The characteristics of the Baader coatings can be seen HERE. I purchased the DSLR version of the filter from Alpine Astronomical. The part number is FBCF400D and is the correct size for both the Canon XTi (400D) and the Canon XTs (450D). One could install a clear glass of equal thickness of the IR filter to maintain viewfinder focus accuracy or just remove the original Canon IR Cut filter and replace it with nothing, but the autofocus would not work. Since the 450D has the live view focusing feature, using it instead would work well for astro imaging (and daytime images) even if the original IR Cut filter was removed and replaced with nothing.
Opening the camera will void your Canon warranty and you may ruin your camera. Proceed at your own risk; I am not responsible for any damage to your camera. I am an electrical engineer and have done other imager modifications including building a peltier cooled webam ; the Steve Chambers long exposure modification (SC-1) to the Philips Vesta Webcam; modified Logitech Fusion and Pro 9000 webcams and modified Canon 300D. The scariest part of the 450D modification are the many ribbon (flat) cable connections involved and removal of the IR cut filter from its holder above the CMOS imaging chip. If you have a problem with your camera after the modification, it would most likely be due to a ribbon cable connection not being fully seated in its connector.
The modification of the 450D is easier than that of the 300D from the standpoint that there is no de-soldering or soldering required. The tools needed are very simple as shown above. From left to right starting at the top of the photo: silicone glue, #000 size philips screwdriver (#Craftsman #45726), jewelers screwdriver set bought at the $1 store, exacto razor knife, magnifying glass, microfiber lens cleaning cloth, cotton photographer's glove and toothpicks. The cotton photographer's glove is for handling the bare replacement filter.
Comment by Skyler: A really handy item was Nitrile gloves. They keep the insides of the camera clean w/o leaving finger oil marks on components. Skyler also recommended using surgical forceps that have long thin noses and work great at grabbing those thin film conductors. See MODIFIER COMMENTS for his advice.
...Before beginning, you may want to take a few "before modification" photos to later check how focus and clarity of image is affected by the modification. Although I didn't, you may want to wear a grounded wrist strap for static protection while handling electrical components.
For the many small screws removed, I taped them to a piece of paper with notes on size, location and assembly step, in the order of removal. I placed the circuit boards removed in Glad plastic food containers to keep dust-free.
1. Remove the lens and place the front cover on the camera body to keep dust out. Remove battery, SD card and viewfinder cap. The viewfinder cap slides up. There will be three screws under the cap; remove these:
2. Remove four screws from bottom of camera as shown:
3. Remove one screw from side of camera:
4. Remove two screws from other side of camera:
5. Remove long screw from near neck strap mount:
6. Remove rubber piece as shown below. It is adhesive backed and can be easily removed by prying one corner up with an exacto razor knife and lifting the rest of the piece off with your fingers. The rubber piece needs to come off to allow the plastic camera body to come apart. It can be easily put back on after re-assembly.
All screws have now been removed and the back half of the camera body will be removed as explained on the next page.
CONTINUED Next Page - Camera Disassembly Continued