The Heliopan 28mm RG 645 Infrared Filter is designed to help capture images of how a subject reflects or transmits infrared light.

Infrared light waves occupy the space in the electromagnetic spectrum behind visible light due to their longer wavelengths. Many surfaces and materials react to, or emit infrared light waves differently than visible light waves, which provide the potential for photographs of subjects or subject properties that are otherwise invisible to the human eye. Such images require an infrared-sensitive medium such as infrared film or a digital photographic sensor which may be more effective when used without the infrared-blocking filters that are frequently built over them.

Conventional light sources such as the sun, photographic strobes, or incandescent lighting may be used to provide infrared illumination. However, because infrared films or digital photographic sensors can be more sensitive to the relatively higher energy and shorter-wavelength visible light those sources also emit, the effects of infrared light can be otherwise obscured. The Heliopan 28mm RG 645 Infrared Filter makes it possible to capture images of how subjects are illuminated by infrared light by blocking near-infrared, visible, and ultraviolet light waves while allowing 90% of infrared light waves 645nm or greater into the lens it is mounted onto.

This filter is constructed from Schott glass for increased optical clarity and features a thin brass filter ring to minimize the potential for vignetting while enhancing durability and jamming prevention.

For Infrared Images    90% of IR 645nm or Above Can Pass    Blocks Near-IR, Visible, and UV Light    ~8x Filter Factor, ~3 Stops    Schott Glass Construction    Multi-Coated    28mm Front Filter Threads    Thin, Brass Filter Ring    Plastic Case

• Designed for use with infrared film or digital camera sensors by filtering out near-infrared, visible, and ultraviolet light
• Allows 90% of infrared light waves beginning at 645nm to pass through
• Effective for infrared films or other media sensitive to infrared wavelengths 645nm or above
• Constructed from Schott glass for optical clarity
• Each glass surface includes four layers of anti-reflection coating to prevent internal ghosting and reflections
• Filter factor of approximately 8x reduces exposure by about 3 stops
• Thin, brass filter ring helps to prevent vignetting, jamming, and provides additional strength
• 28mm front filter threads allow for use with other filters
• Plastic case for storage and transport

Related Questions and Answers

Q: 1. There are two versions of the M28 ASPH produced, one in Germany the other in Portugal. Is there any markings or visual clues on the lens that indicates where it was produced ?

A: Aside from the engraving on the bottom of the lens, the price is also less if it's made in Portugal

Q: 2. Is this an opteka clone of the Fuji 27mm 2.8 except manual and declicked for video? Or is it a new design by opteka?

A: It is not a clone of the Fuji as it is a different focal length, but it is very similar and it is fully manual with a de-clicked aperture.

Q: 3. Can I use this lens for occasional landscape photography?

A: Yes, it is a relatively wide lens and would work well for landscapes.

Q: 4. Is the barrel made of aluminum or brass?

A: The barrel in the Leica Elmarit-M 28mm f/2.8 ASPH. Lens is made of aluminum.

Q: 5. Does this newer Summicron come with metal hood or plastic?

A: The included lens hood with the Leica Summicron-M 28mm f/2 ASPH. Lens is comprised of metal.

Q: 6. what is a protection ring?

A: The protection ring is just a ring that finishes the clean aesthetic of the front of the lens when not using the hood or other filters and it protects the threads as well.

Q: 7. Is the lens hood included with the lens?

A: Yes, the Leica Lens Hood for Summicron-M 28mm f/2 (Black) B&H # LEH28F2BAF is included.

Q: 8. which leica film bodies has a 28mm window?

A: reference from a Leica forum: The only M-mount viewfinders that showed "what happens around" with a 28mm lens were all on film cameras: the special low-magnification 0.58x finder of the M6 (available a la carte for the M7/MP/current film Ms)

Q: 9. Does this dedicated lens shade come with the rectangular rubber lens cap?

A: Yes, the lens cap is included.

Q: 10. How do I know that the lens is made in Portugal or Germany ? You are not stating this detail.

A: The Leica Summicron-M 28mm f/2 ASPH. Lens BH #LE282SM • MFR #11672 that B&H sells are made in Germany.