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New UV-Pass Filter from UVR Optics: the AndreaU MK II remake of the AndreaU


Andrea B.

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[uVP has no affiliation with any vendor. We do permit one-time new product announcements after approval by either Bjørn or Andrea.]

 

Reed Curry from UVR Optics has announced a remake of the AndreaU.

[LINK: http://www.uvroptics...dex.php?AndreaU ]

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The new Andrea 'U' MK II UV bandpass filter from UVROptics represents a complete re-invention of the popular Andrea 'U' while retaining the excellent transmission of the 370nm-400nm bandwavelengths of its predecessor. http://uvroptics.com/graphics/solar-spectrum400.jpg

 

These wavelengths contain most of the UVA available in solar radiation. As you can see from the illustration above, the amount of ultraviolet light in sunlight diminishes rapidly as the wavelengths get shorter. Using this high end of the UV wavelengths results in greatly reduced exposure time, making UV video photography practical.

 

Through a blend of ionic glass filters, the Andrea 'U' MK II blocks a minimum of >OD5 with an average of >OD6 for the 405-1100nm range. This extreme near-Infrared blocking makes ultraviolet photography possible even in conditions such as rainy days or nighttime when the amount of UV is low, the percentage of NIR wavelengths may be high, and a long exposure time is necessary.

 

Most UV bandpass filters were designed for astronomy and are "dichroic" also known as "interference" filters. Dichroic filters offer excellent performance when used for astronomy, because the incoming light has been collimated by the lenses of the telescope; insuring that the light strikes the filter at a ninety degree angle. For applications where a wide-angle lense is required, the dichroic filter provides misleading results. Dichroic filters shift their cut-off wavelength according to the angle of incidence of the incoming light. This makes the dichroic filter difficult to use with wide-angle lenses. The Andrea 'U' Mk II, on the other hand, is an absorptive filter, providing an accurate, reliable image without bandshift. The Andrea 'U' Mk II also produces a sharper image. This capability is especially attractive to scientists who will now be able to register the true UV reflection of objects. http://uvroptics.com/images/AndreaU_MKII.jpgThe graph to the right is representative of the performance of the filter based upon mean values.

 

The Andrea 'U' has already proven to be popular worldwide among both technical and art photographers. The Andrea 'U' Mk II with its exceptional out-of-band blocking, high-speed, low-cost, and durability will enable more photographers to enjoy the world of UV reflectance photography.

 

Andrea 'U' MK II in black 52mm threaded ring. $249.00 USD plus shipping.

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