Correct Use of the Polarizing Filter - Practical Guide
The polarizing filter has a special place in the arsenal of the photographer's optical filters.
If colored filters predominantly blocks the light with a certain wavelength, polarization filter stops light radiation of any wavelength, which varies between a plan and let pass the plan in which oscillates perpendicularly.
The filter is composed of an optical track and a skeleton.
Optical track is made of material particular, with the polarization filter (special plastic Microcrystalline called "Polaroid").
Skeleton is composed of two rings: one fixed, provided with screw or bayonet, mounted to the objective ("mos"), and second, randalinat, the filter is mounted and can rotate freely precedent, to obtain maximum effect of the filter.
Natural light, as otherwise, and any source of artificial light has properties of both wave and particle (photon).
Feature is the wave oscillation perpendicular to the direction of propagation (vector variation) in all plans: left-right, top-down and in all intermediate positions, so that, on the section, vectors of oscillating handle all possible diameters of a circle.
Circumstances of polarized light: blue sky (in a good portion determined - by refract light to pass through various atmospheric layers), surfaces with water, glass, plastics, various surfaces covered with lakes and paints, etc..
Which filter is better, circular or linear? If you use a standard filter, linear polarization, it is possible to have problems with functions and auto-focusauto-exposure - the apparatus equipped with these functions.
It is also possible that even classic devices present some abnormalities in calculating exposure (measuring devices equipped with TTL).
Why? If the optical path these functions break glass prisms or mirrors, the light polarized in a plan will be mitigated in a dependent relation cos (alpha), and much more as the angle of incidence is near the Brewster angle.
A circular polarization filter is composed of a polarization filter used Linear and immediately behind is placed a plate made of a material birefringent.
Birefringent material - like cellophane - transmit light soon in some directions than in others, due to its anisotropic structure, which leads to different refractive indices, the direction with maximum speed and minimum, are called fast axis and slow axis respectively and are delayed at 90 degrees.
Thickness plate is calculated such that it represents one quarter wavelength (quarter, Q that is 90 degrees usually light green, the most sensitive to human eye).
Why unwanted reflections occur even when using a polarization filter? Reflected light - any non-metallic surface-is polarized in a certain measure.
The degree of polarization depends on the angle of incidence and refractive index of the two environments.
At an angle (Brewster angle), the light is entirely polarized; at different angles, polarization is only partial.
Angle value Brewster is about 55 degrees to the current (water bottle).
If a place polarization filter on the endorsement by your objective and be seated in an angle ca.
55 degrees to the glass window of the store by a suitable rotation Filter polarization will cancel most of the reflections.
When should I not use the polarization filter? In the absence of polarized light, a polarization filter is not just a neutral filter that increase exposure to 1-2-tier (or more).
If the light that you picture is a little, that this filter leads to prolongation of exposure, and you risking to get a move! Correct adjustment of the polarization filter remove unwanted reflections from windows.
Notably playing correct color car paint removal by blue reflections.
Reflections metal surfaces are not polarized, so filter does not improve the picture.
Regarding the metal objects - water glass and most often - how to remove the optimum amount - that is, the angle Brewster - with polarized light so the ratio will be lower, at 90 degrees will be unpolarized light and polarization is to no use.
And in this case, light reflected by the leaves of trees or grass, will be polarized, so you can improve the picture.
If colored filters predominantly blocks the light with a certain wavelength, polarization filter stops light radiation of any wavelength, which varies between a plan and let pass the plan in which oscillates perpendicularly.
The filter is composed of an optical track and a skeleton.
Optical track is made of material particular, with the polarization filter (special plastic Microcrystalline called "Polaroid").
Skeleton is composed of two rings: one fixed, provided with screw or bayonet, mounted to the objective ("mos"), and second, randalinat, the filter is mounted and can rotate freely precedent, to obtain maximum effect of the filter.
Natural light, as otherwise, and any source of artificial light has properties of both wave and particle (photon).
Feature is the wave oscillation perpendicular to the direction of propagation (vector variation) in all plans: left-right, top-down and in all intermediate positions, so that, on the section, vectors of oscillating handle all possible diameters of a circle.
Circumstances of polarized light: blue sky (in a good portion determined - by refract light to pass through various atmospheric layers), surfaces with water, glass, plastics, various surfaces covered with lakes and paints, etc..
Which filter is better, circular or linear? If you use a standard filter, linear polarization, it is possible to have problems with functions and auto-focusauto-exposure - the apparatus equipped with these functions.
It is also possible that even classic devices present some abnormalities in calculating exposure (measuring devices equipped with TTL).
Why? If the optical path these functions break glass prisms or mirrors, the light polarized in a plan will be mitigated in a dependent relation cos (alpha), and much more as the angle of incidence is near the Brewster angle.
A circular polarization filter is composed of a polarization filter used Linear and immediately behind is placed a plate made of a material birefringent.
Birefringent material - like cellophane - transmit light soon in some directions than in others, due to its anisotropic structure, which leads to different refractive indices, the direction with maximum speed and minimum, are called fast axis and slow axis respectively and are delayed at 90 degrees.
Thickness plate is calculated such that it represents one quarter wavelength (quarter, Q that is 90 degrees usually light green, the most sensitive to human eye).
Why unwanted reflections occur even when using a polarization filter? Reflected light - any non-metallic surface-is polarized in a certain measure.
The degree of polarization depends on the angle of incidence and refractive index of the two environments.
At an angle (Brewster angle), the light is entirely polarized; at different angles, polarization is only partial.
Angle value Brewster is about 55 degrees to the current (water bottle).
If a place polarization filter on the endorsement by your objective and be seated in an angle ca.
55 degrees to the glass window of the store by a suitable rotation Filter polarization will cancel most of the reflections.
When should I not use the polarization filter? In the absence of polarized light, a polarization filter is not just a neutral filter that increase exposure to 1-2-tier (or more).
If the light that you picture is a little, that this filter leads to prolongation of exposure, and you risking to get a move! Correct adjustment of the polarization filter remove unwanted reflections from windows.
Notably playing correct color car paint removal by blue reflections.
Reflections metal surfaces are not polarized, so filter does not improve the picture.
Regarding the metal objects - water glass and most often - how to remove the optimum amount - that is, the angle Brewster - with polarized light so the ratio will be lower, at 90 degrees will be unpolarized light and polarization is to no use.
And in this case, light reflected by the leaves of trees or grass, will be polarized, so you can improve the picture.
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