When correctly aligned, a polarizer removes what is usually denominated as "specular" reflections. A specular reflection has taken very little energy absorption from the surface it bounced from, so it basically contains the illuminant light colour and nothing more. It mixes "white" with the colour of the surface.
A skin surface is full of very small specular reflections, if you remove them you get a deeper skin tone, since a smaller percentage of the light reflected from the surface is just "pure white".
A polarizer can also have varying degrees of blocking (and transmitting!) depending on wavelength. So if the polarizing layer blocks red more than the others, you will change the wavelength composition sum of the surface. This changes the average colour....Show more →
Thanks for the explanation.
Hmmm so would the use of a circ polarizer depend on the person? It sounds like sometimes it could be flattering, sometimes not.
I've never tried to use a polarizer for portraits, but I think that in general it's not a good idea. Nothing should stop you from trying it of course, but removing the specular reflections removes the glow from a person's skin and can make it look too matte, I think.
I have never tried it myself, but that sounds like a good idea. In fashion photography they have to use tons of make up and spend hours retouching the photos to remove the specular reflections on the skin, especially around the forehead and nose. A polarizer could be the simple answer but there must be a reason why it isn't used for this purpose.
I haven't tried it myself either, but I recently read a remark from someone, saying that it produced a very harsh rendering of the skin. A bit like using a blue filter on a B&W portrait.
You can get really striking effects by combining a pol.sheet over the softbox and a polarizer on the lens. Then you can control the "harshness" of any lightsource to any precision you'd want. But you'd need a lot of practice to get a "feel" for the usage.
In direct sunlight it helps with keeping the highlights within the histogram limits. Specular highlights are typically the brightest points of the picture.
Trying to see any difference in human skin with only a CPL or PL on the camera is just about impossible in most lighting tho. I suppose if the subject is SUPER oily or sweaty and the lighting is hard you could tho.
Boy do I cringe when I read the words "light wave particles".... :-)
That's about the same as saying that anything making a sound is creating small particles called "soundons" that are sent of from the source through air and then bounce against your eardrums.
theSuede wrote:
Boy do I cringe when I read the words "light wave particles".... :-)
That's about the same as saying that anything making a sound is creating small particles called "soundons" that are sent of from the source through air and then bounce against your eardrums.
If you don't like the idea of sound-wave particles, then I suggest that you avoid taking any university level solid-state physics courses. Physicists actually do describe acoustic waves (usually within solid materials) as quantized "particles," which we call "phonons" (not "soundons"). Just like light/photons, in most typical sound situations you are dealing with such a huge number of phonons that the individual quanta are ignored and the overall mass is treated as an overall continuous wave. However, in very low-temperature applications (where there are few vibrations, so the characteristics of individual phonons become observable), the quantized "particle" nature of sound waves becomes important.
I know, but "soundons" - "ljudoner" on Swedish sounds much cooler. :-)
That a pressure wave transmitted through a dense media with fairly static physical properties (a solid frozen to liquid nitrogen temperatures) can be modeled as a particle once you've broken down the propagation to quantum mechanics doesn't mean that you should THINK about the wave as a particle. If you do, then you might arrive at all sorts of strange assumptions such as that the mass of the object changing if you shake it - and so on...
THINKING about waves as a particles is the main no-no for me. The particle implies matter (and hence a mass).
theSuede wrote:
I know, but "soundons" - "ljudoner" on Swedish sounds much cooler. :-)
That a pressure wave transmitted through a dense media with fairly static physical properties (a solid frozen to liquid nitrogen temperatures) can be modeled as a particle once you've broken down the propagation to quantum mechanics doesn't mean that you should THINK about the wave as a particle. If you do, then you might arrive at all sorts of strange assumptions such as that the mass of the object changing if you shake it - and so on...
THINKING about waves as a particles is the main no-no for me. The particle implies matter (and hence a mass)....Show more →
They actually do have mass
Think E=mc^2: a warm ("shaken") chunk of material actually does have a tiny tiny tiny bit more mass than an identical colder one, due to its internal kinetic energy from the vibrations. Reality can be a lot weirder than you expect if you look too closely
