*Please note that this is a special order item and will take approximately 8-10 weeks for delivery. All special order items are non-refundable.
The Heliopan 25.5mm IR BG (40) Filter is designed for use with black and white and color films that are sensitive to certain values of infrared and UV light not visible to the human eye. Using traditional contrast filters such as a yellow 12, red 25 or green 15 will produce a color shift which may not be desired in the final image. Greens may become blue, red becomes green and yellow becomes blue/green and infrared becomes red. When this filter is used, infrared light waves at 860 nanometers are blocked by approximately 99.1%. Infrared light waves at higher frequencies are further impeded where attenuation is achieved at 890 nanometers with infrared light waves blocked by 99.2%. This process helps to ensure that the light that falls on the camera's sensor is limited to the visible spectrum. Potential infrared color shifts are prevented or minimized, which preserves color accuracy throughout the frame.
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