Rob-F
Likes Leicas
So I was in a parking lot at Big Bend National Park, eyeing some spectacular mountain formations. I shot some with the D700, and then decided to get out the 52mm Nikon polarizing filter that has been in my bag since 1989. I put it on my 50/1.4 Nikkor, added its dedicated hood, and shot a few frames on Aperture Priority. Then I ducked into the shade of the 4runner to check the exposures.
Nothing. I got a black frame. So I switched to manual exposure, opened up two stops, and tried again. This time the exposure was not bad at all. One minor correction, and I was on my way to some pretty nice shots.
But I need to know why the D-700 didn't give me the right exposure on aperture priority. I recall that some years ago circular polarizers came out, and this was required for something: autofocus, or (apparently) in-camera exposure metering. Or both. Is that it? I just need to buy circular polarizers for my various filter sizes, and the camera will meter correctly? Or am I missing something?
Nothing. I got a black frame. So I switched to manual exposure, opened up two stops, and tried again. This time the exposure was not bad at all. One minor correction, and I was on my way to some pretty nice shots.
But I need to know why the D-700 didn't give me the right exposure on aperture priority. I recall that some years ago circular polarizers came out, and this was required for something: autofocus, or (apparently) in-camera exposure metering. Or both. Is that it? I just need to buy circular polarizers for my various filter sizes, and the camera will meter correctly? Or am I missing something?
michaelwj
----------------
Weird. If I remember, circular polarisers were for phase detect autofocus initially. But, the D700 has some pretty sophisticated metering which might take into account polarisation?? I wonder if changing the metering mode will make a difference?
Dwig
Well-known
Correct. The AF system in SLRs, both digital and film, can be blinded by conventional polarizers. Most metering in modern AF SLRs also can be severely impacted by conventional polarizers. Even some of the pre-AF SLRs' metering comes to grief unless circular polarizers as used.
Ronald M
Veteran
If scene looks polarized from both front and back it is a linear pola and is not compatible with the metering system. The work around is meter with pola in place and rotate to get maximum or minimum exposure, I forget which. Set camera, rotate for proper effect. #2 work around is meter normally without pola, add filter, open 1.5 to 2 stops, rotate for effect, take picture. Exposure correction is same all the time so you only need to establish it one time.
If you see pola effect from only one side, it is a circular pola and you did something wrong.
There is no difference in final effect from either filter type. Thank heaven for chimping.
If you see pola effect from only one side, it is a circular pola and you did something wrong.
There is no difference in final effect from either filter type. Thank heaven for chimping.
Rob-F
Likes Leicas
I'm not clear about some of these words: "from both front and back . . . " And "from only one side. . ."
From front and back of what? From only one side of what?