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To: Toliph
Blue Filters (B) Blue Filters transmit light in the blue spectrum and are named after the wavelength at which their transmittance attains the maximum value. They are used for 3-color separations, selection of wavelengths, and color compensation.

They appear blue due to scatter.

33 posted on 09/12/2016 5:28:15 PM PDT by steve86 (Prophecies of Maelmhaedhoc O'Morgair (Latin form: Malachy))
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To: steve86

Unlikely it is scatter, unless there is some very bright light source that is directly over her head in those photos.

More likely is they appear blue due to an reflective interference filter coating on the front of the lenses that preferentially reflects on-axis blue light, and passes everything else (i.e., the yellow light). Such glasses are useful because the human eye is very poorly focused for blue light (this is why it’s hard to look at blue LED Christmas lights, which always appear blurry). It’s the same reason shooting glasses are yellow.


34 posted on 09/12/2016 6:33:24 PM PDT by Toliph
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