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Observatoire astronomique amateur, astronomie, astronomique, astrophotographie, observations, ciel nocturne, photographie du ciel, nuit   


Le matériel

Le filtre Minus Violet

 Lumicon International


Minus Violet Filters



Lumicon Minus Violet Filter for color or B&W photography

The Lumicon Minus Violet Filter greatly improves photographs taken through lens systems, producing pinpoint star images. It is especially recommended for all telephoto lenses. This filter is made from optically flat, specially-made colored glass, and has anti-reflection coatings on both surfaces. The Minus Violet filter passes the maximum amount of visible light, including the full blue, green, yellow, and red portions of the spectrum. It absorbs violet and ultraviolet light below 420nm, thus eliminating blue halos around bright stars in color photography. In B&W photography it eliminates bloated and swollen star images caused by violet and ultraviolet light which telephoto lenses cannot focus perfectly, due to chromatic aberration. The Minus Violet filter slightly reduces light pollution.

Recommended Films
All films can be used with the Minus Violet Filter; hypersensitized 2415 is the recommended B&W film
available from any of Lumicon's authorized dealers.

Filter Factor
Increase exposure by only about 10% for the Minus Violet Filter.

For Viewing
The Minus Violet Filter can eliminate or greatly reduce the blue halo sometimes seen around stars in
refracting telescopes. It is ideal for observing the moon and planets.

Lumicon Minus Violet Filter - 48mm LF-MV05

Lumicon Minus Violet Filter - 58mm LF-MV10

Lumicon Minus Violet Filter - 72mm LF-MV15