linear polarizers are good enough for the Z's

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Boudewijn van der Drift Contributing Member • Posts: 679
linear polarizers are good enough for the Z's

OK, my theory was not very commented.

So a bit more practical:

I took my old polarizer (70's).

Found it did not fit any Z lens, I have.

Dug up my oldest lens (1973, together with an F2, Saudi Arabia, taxfree :-)))

First challenge, what is the focal length of a non CPU zoom? I made that the geometric average. Which had to be rounded off anyway, so any average could work.

Mounted that on camera. With pola:

Waited for clear sky.

Our church was in restauration (did not know). Pity, since I was curious what the gilded clock dial would do

Found that blue peaking for focus is not the best against blue sky (very good for faces and foliage though, so it stays).

at maximum extinction.

At minimum extiction

sans polarisateur

This was all with 1/125 and f8, so the autoiso shows the stops lost. All undoctored .jpg's SOOC.

I don't see the white on black shooting data, but trust they will appear after posting, otherwise I will add the autoiso's later.

Perhaps one last further simplified simplified explanation.

The old camera's had polarizers, these are now called linear polarizers.

DSLR's use a halfmirror for lightmetering (somewhere in or near the pentaprism I think).. But such a mirror also is a polarizing device. When you turn your lineat polarizer, the amount of light going to the metering will vary!

So after a linear polarizer has done its thing, there is a second filter that depolarizes the light (unwanted reflections etc are then already removed of course). The metering system then has then no problem anymore. This combo is now called a circular polarizer.

Mirrorless camera's don't need the problematic halfmirror.

 Boudewijn van der Drift's gear list:Boudewijn van der Drift's gear list
Panasonic Lumix DMC-LX3 Nikon Z7 Nikon Z6 Nikon Z 70-200 F2.8 VR +2 more
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