Daytime Infrared Images:
An advantage of replacing Canon's IR Cut filter with a coated clear glass window is that add-on IR PASS filters can be used for infrared imaging. The following infrared images were taken using the popular infrared "Hoya R72" filter. In bright light the camera's autofocus works to some degree. Since the infrared HOYA R72 filter is mounted on the camera lens, mostly infrared light is being directed to the autofocus (AF) sensors at the base of the camera. A diagram of the light path can be seen HERE. Although the diagram is for a Nikon DSLR, it is applicable to the Canon DSLRs. The viewfinder image will be dark with the infrared filter attached so focusing manually through the viewfinder is not possible. Precise focus is best achieved by trial and error using the camera LCD display. Camera lenses need to be "short focused" a little to achieve focus with infrared light as compared to normal light. Some camera lenses have "red" focus shift markings for infrared. I have noted where my wide angle zoom lens focuses best for infrared at infinity, and use that setting for scenic daytime infrared images.
A color correcting filter, the "X-NiteCC1 (IR Blocking) Filter" by maxmax.com was used for normal daylight images.
The following images are "mouseover images". You will need to have scripting allowed in your web browser for this to work. Move your mouse cursor over the image and you will see the normal image of the same scene. Move the mouse cursor off the image to go back to the infrared image:
Move cursor on and off image:
Imaging in infrared results in clear sky appearing dark and vegetation such as grass and tree blossoms appearing bright (white). Infrared cuts through sky haze.
The following summer scenes are not mouseover images:
For more daytime infrared images CLICK HERE.
To learn more about Infrared Imaging with a Digital Camera, see the Digital Photography For What It's Worth article: Infrared (IR) Basics for Digital Photographers—Capturing the Unseen