Infrared filters

A very interesting area in digital photography is infrared images for creative and artistic effects. Heliopan filters made from Schott glass, pass only the exact areas of the IR Spectrum: RG695(89B), RG715(88A), RG780(87), RG850, RG1000. For digital landscape pictures we recommend the R715 to RG830 filters.

Both CMOS as well as CCD chips are sensitive to IR light, (because the active pixel surfaces have a streamed on dichroic coating on a substrate that is
sensitive to IR light.) your digicam can therefore be used for IR photography. When using IR filters it is important that your digicam measures the light with TTL metering. This applies to almost all DSLRs. Compact digicams often have a separate sensor in the front. Test: Switch the time to AV on Automatic and hold the IR Filter in front of the lens. Then see if the exposure time increases. You can measure through the filter. To avoid stray light cover the viewfinder eyepiece.

• Subjects with a lot of sun light have the greatest IR radiation.
• Always use a Giottos Tripod because of the long exposure times.
• Compose your image before mounting the filter.
• Because of the focus shift set the distance manually to the IR index on the lens or use the AF setting with the filter in place and do not use
  open aperture. AF sensors can sometimes partially focus to IR. Alternatively make a test with a series of adjustments manually going
  from the normal sharp setting in small steps into the close-up area.
• Quite often the exposure needs a lot of increase. Use the +/- correction or the manual mode for additional over exposure.
• In the black and white mode you can see the proper exposure in the camera display. In the color mode you can see it in the histogram
  display. This applies especially for the red channel.

Use JPEG to avoid the complex signal processing in the RAW mode.

• For brilliant B&W reproduction use LAB mode and use the L channel or only the Red channel.
• Since the contrast of the image is often too low due to the camera’s internal calculations simply reset in your enhancement software the black and the white points.
• The simple digital method will give you dramatic IR Images eg. Landscapes which were only possible before with special film.