"TP" wrote in message
news
"john" wrote:

Hi folks,

I'm trying to find out more information about the filters I should be
using,
but when I try to search on the internet, I usually just keep getting
links
to sites selling filters, not giving information.

I'm confused as to the difference between UV Protector filters and
Skylight
filters. On the one site where I found information, it said this about UV
Protector filters:

UV filters are wise initial investments. They help protect your
valuable investment from dust, moisture and scratches, which
can lead to costly repairs. If desired they can be left on the
lens at all times for protection. UV filters provide additional
benefits of correction for Ultraviolet (UV) light which can
register on film and videotape as a bluish cast and can
obscure distant details. Ultraviolet filters allow you to correct
for the UV effect to varying degrees.

And then it said this about Skylight filters:

Due to its light pink color, the Skylight reduces the bluish cast
of daylight and produces a pleasing, warmer picture tone.
Wise initial investments, they help protect your lens from
dust, moisture and scratches, which can lead to costly repairs.
If desired they can be left on at all times for protection.
Skylight filters provide additional benefits of correction for
Ultraviolet (UV) light which can register on film and videotape
as a bluish cast and can obscure distant details. Also used to
reduce the bluish cast common with some electronic flash
units.

They almost sound exactly the same.


Apologies for replying via TP's post - I can't see the OP for some reason.

A similar question has come up several times on the group, and a while back
I posted a link to a transmission chart that shows how different the
characteristics of UV and Skylight (1A) filters a

http://www.bard-hill.co.uk/filters.html

A UV filter attenuates actual UV more strongly, and so will be a better bet
where excess UV is a problem - near the sea, at high altitude, at very low
latitudes. (This issues arises because film can see UV light, and renders
it blue, that the human eye can't see: so an excess of UV that is invisible
to us will make photographs look too blue, and also add haze to distant
views.) A UV filter should attenuate visible light very little, but it will
reduce the extreme purple end.

The Skylight doesn't attenuate UV as much or as sharply, but it does take
out a little more of the visible light, notably in the blue-green range.
This means it makes scenes look slightly warmer. It is designed to correct
for the excess blueness of scenes shot in shade on cloudless days, or
outside generally when cloud obscurs the sun - ie. when the light is coming
mostly from the blue sky. Definitely helps (on slide film) if taking
portraits in shade, but the effect is not _that_ marked otherwise.

I use UV filters more often than Skylights, but I do sometimes use a
Skylight in shade. For warming per se I'm more likely to use an 81 series
or a KR filter.



Peter