The Filters We Need With Digital...

Started Oct 5, 2008 | Discussions thread
OP Joseph S Wisniewski Forum Pro • Posts: 34,130
A "bonus" use for the polarizer...

Joseph S Wisniewski wrote:

One - The Polarizer

This is so obvious I shouldn’t need to get into "why" you need it,
but I’m me, and that means I’m going to talk about it anyway. Any
time light moves from air to a transparent substance, some of the
light doesn’t penetrate into the transparent substance and is
reflected away. Whether the light hits water on a lake, the natural
oil on human skin, clear cellulose and wax on plant leaves and
flowers, lacquer on a car or a guitar, or glass on a building, there
are reflections. The reflections are “white light”; they “fill in”
the color and reduce saturation. They reduce the detail visible under
the clear substance. The blue of the sky is also polarized, and a
polarizer can deepen the blue, and keep it from blowing out and
rendering your sky a cloudless white or a drab gray.

I was just reminded of a second reason I use the polarizer, a "bonus", as it were.

The polarizer absorbs about a stop and a half of light. This might mean that you don’t want to use it with sports, where you need all your light to get you high shutter speeds. But there are times when you just want to get rid of some light. When you’re shooting outdoors, and your digital camera doesn’t really work at an ISO lower than 200 (and even the ones that say they go down to 100 are typically better at 200) then the good old “sunny 16” rule says that you’re at 1/200 sec at f16, 1/6400 at f2.8, and that’s pretty much the limit for most cameras. You’ve paid a lot of money for fancy 50mm and 85mm f1.4 or f1.8 (maybe even f1.2) or 105mm or 135mm f2.0, and you can’t use them outdoors at f2.0. The polarizer to the rescue! That stop and a half is just enough so that you can shoot 1/8000 sec and f1.4 on a sunny day at ISO 200.

It's a quick and dirty "neutral density"...

-- hide signature --

Rahon Klavanian 1912-2008.

Armenian genocide survivor, amazing cook, scrabble master, and loving grandmother. You will be missed.

Ciao! Joseph

 Joseph S Wisniewski's gear list:Joseph S Wisniewski's gear list
Canon EOS 5D Mark II Nikon D90 Nikon D2X Nikon D3 Nikon D100 +43 more
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