I think you're both wrong. While the 81 series filters definitely
filter blue they are designed to filter the visible part of the blue
spectrum as evidenced by the fact that both 81A and 81C have a 1/3 stop
effect on exposure. They are designed for warming daylight pictures.
Whatever is done by an 81 series filter is fully within the capability
of color balancing your digital images.
True UV and haze filters filter only the UV portion of the spectrum and
consequently have no filter factor. Even the Tiffen UV haze 2A filter
which purports to block 100% of UV has a 0 filter factor. There's a
rather bewildering array of UV/Haze filter designations (some of which
differ by manufacturer) and the only way I know to sort them out is to
read the spec sheet. Not all of the manufacturers give the specs at B&H
but Tiffen bares all.
But, as a result of this discussion, if I ever get to high altitudes
again I'll be sure to get myself a UV haze 2A before I go.
Chuck Norcutt
On 8/2/2014 1:57 AM, Moose wrote:
On 8/1/2014 4:24 PM, Wayne Harridge wrote:
Probably not an 80A:
http://www.hoyafilter.com/hoya/products/coloredfilters/80a/ ,
more likely 81A:
http://www.hoyafilter.com/hoya/products/coloredfilters/81a/
Brain fart. Wayne says what I meant. 81A and the stronger 81C are the
filters for high altitudes.
Apologetic Moose
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