Hi all! Today we will talk about using a polarizing filter in product photography.
To my shame, I only tried a polarizer for the first time a year and a half ago. For some reason this topic has bypassed me before. Yes, I read articles about a magic filter that removes reflections from water and glass... but for some reason it didn’t grab my attention, so I forgot about this filter for several years. And so, one day I attended a master class with one very good photographer, who showed how a polarizer works. So he said casually: “Well, now let’s remove the glare using a polarizing filter...”. Wow! I said out loud, and quite loudly. And I thought to myself: this must be black magic. But realizing that everyone was looking at me as if I had fallen from the moon, I fell silent. And he waited until the end of the master class so he could go to the store to buy a polarizer?
I think I'm not the only one who doesn't know anything. And for those who still don’t know what a polarik is - this article (and there will be a video). If you are already in the know, you don’t have to read, there will be no revelations for you.
So, polarizing filter helps remove reflections, glare and increase color saturation. A polarizing filter looks like any other filter, but it's not entirely true. It consists of 2 parts that rotate relative to each other. 
And just by rotating the front lens, we change the resulting effect. It is screwed, as you probably already guessed, onto the lens, in front, where all the other filters are. 
And here its first serious drawback reveals itself: for lenses with different thread diameters, you will have to buy your own polarizer. And they cost a lot. Just a word of warning: do not buy cheap filters for 1000-1500, especially if you have a good lens. The saying absolutely applies here: “The miser pays twice.” Unfortunately, I checked it from my own experience (by the way, was I also warned?). The bottom line is that the glass quality of these filters is so poor that they ruin the frame, and through your expensive lens with good glasses a picture already spoiled by a cheap filter passes through. The image becomes cloudy and the sharpness drops significantly. In short, no need.
Let's move on to practice.
Here’s a common problem: we’re filming some kind of garbage, but for some reason we need to remove a sharp glare, for example, the customer doesn’t like the glare (this is actually not uncommon) - we use a polarizer and….. 
I think this is awesome!
Ischo example: 
The examples show how glare has decreased and color saturation has increased.
Unfortunately, things are not always that simple. The effectiveness of a polarizing filter is influenced by many factors. (for example, angles of incidence of light) Therefore, in order to know what to expect from a polarizer, quite a lot of practice and experience is required. By the way, due to the influence of the angles of incidence of light on the effect produced by the polarizer, it is not recommended to use it at wide angles. Polarization may occur unevenly, for example in the center there will be rich in color picture, but not on the sides, and this can be very noticeable.
Polarizing filters for photography come in two types: circularly polarized and linear. If you are too lazy to read a lot of text without pictures, then you need to take a filter with circular polarization. But if you can’t fall asleep without understanding why, then read on.
First, a little theory.
Polarization is a characteristic of light. If light is represented in the form electromagnetic wave, then polarization determines the direction of transverse vibrations. The light that comes into your lens is mostly unpolarized, that is, it does not have a clearly defined direction of transverse vibration.
Polarization cannot be seen with the naked eye, but it can be seen through a polarizing filter, which is sensitive to these transverse vibrations.
The purpose of the filter is to pass some directions and block others. When reflected from non-metallic surfaces, light is polarized in a very specific way, so the filter allows us to control such light, as already described in the story about the polarizing filter. This is why the effect of a polarizing filter cannot be replicated in Photoshop; it can only be approximately imitated.
Linear polarization. Linear filters perform one very simple function– they transmit only light with polarization in one plane. The filter can be rotated by choosing the plane with polarization in which the light will pass. That is, the output of a linear filter is always linearly polarized light:
These are very simple and inexpensive filters, but they are not suitable for modern DSLR cameras. They are perfect for ancient non-autofocus cameras without automatic exposure metering, as well as point-and-shoot cameras.
The point is that in DSLR cameras there is a translucent surface that directs approximately 2/3 of the light directly into your right eye, and the remaining 1/3 passes through and hits the very thing (RGB sensor) that is responsible for autofocus zones, matrix exposure metering and takes into account color and distance to the object (Canon still cannot do this, he sees only black and white). This allows the camera to see roughly the same thing as you, which is why it knows so well what settings you need in automatic mode. So there are two sensors in total in the camera: one receives the image, the other controls the settings. Here is an RGB sensor, for example, in Nikon D7000:
Well, this translucent surface is sensitive to polarization, which means that the amount of light hitting the RGB sensor will differ depending on the orientation of the filter, which will lead to errors in exposure estimation and sometimes incorrect autofocus.
In addition, there may be other elements that are sensitive to polarization, such as some lenses in the lens. Therefore, it is best to look in the instructions to see what types of polarizing filters are suitable for your camera. To save you time, I will say that all modern DSLR cameras are suitable only for a circular polarizing filter.
Circular polarization. There is a misconception that a circularly polarized filter only transmits circularly polarized light. Only those who do not read our articles think this way. However, our attentive readers (everyone immediately remembers the title picture when they hear the word “attentive”) are aware that everything is quite the opposite. The point of a circular polarizing filter is that it converts any polarization into a circular one. This means that such a filter is suitable for all cameras, including older ones, allows you to correctly determine the exposure and does not interfere with autofocus.
A filter with circular polarization is more complex than a linear one, and therefore more expensive. There is a regular linear filter on the outside, and a quarter-wave plate is glued to the inside, which allows linear polarization to be converted into circular. We won’t go deeper into physics, but if you’re interested, a quarter-wave plate is a special material with double refraction. A typical example of such a material is calcite, or more precisely, Iceland spar. Well, we are already one step away from quantum mechanics, although the site is about photography.
Now let's move on to practice.
How to determine what polarization your filter is? Even if there are no inscriptions on the filter, this is very easy to do. Go to the mirror, turn on the light, although it’s better in the reverse order, it’s cheaper. Look through the filter like you would through a monocle. The outer side is from the eye, the inner side is from the mirror. If the filter is opaque in reflection and turns into a black circle, then it is a circularly polarized filter. If the filter is transparent in reflection, then either you turned it the wrong way, or it is a linear filter.
How can you tell whether your camera requires a circular filter, or whether an old-fashioned linear one will do, since you skipped the previous paragraphs? Turn on the camera, turn on some artificial light (a regular incandescent lamp will do), hold the filter up to the lens, aim at something non-shiny, like a wall. Twist the filter. If the exposure changes (ISO, shutter speed or aperture increases), then the filter is not suitable for your camera. You don’t have to turn the circular polarization filter, but if you’re interested, try it, nothing will change. There is a nuance here, the camera must be able to sense a difference in exposure of 1/3 or 1/2 stop. If the minimum step is 1 stop, then the difference may not be noticeable. In Nikons, the minimum step is usually set in the Custom Settings Menu, namely b3 (at least on the D700).
Is it possible to use a filter with linear polarization, although you need a circular one? Can. Only you must take into account that depending on the orientation of the filter, your exposure metering will be in error. Check the result on the screen and don’t be afraid of anything.
Which filter should I buy, circularly polarized or linear? You should only buy ones with circular polarization, because such filters work excellently on any camera.
Which filter manufacturer is better? Don't know. I tried different filters, they are all about the same. Personally, I have a German B+W filter.
By the way, a common Soviet polarizing filter PF-52 with linear polarization. A little inconvenient, but you can use it.
Tell us about your polarizing filter in the comments, it will help other readers make their choice.
Polarizing filters are good for shooting when sunlight, as they reduce glare from non-metallic surfaces and add richness to colors. The effect created by a polarizing filter cannot be replicated in processing. In this tutorial we will learn how to use this filter correctly.
What does a polarizing filter do?
There are 2 types of polarizing filters, linear and circular (circular). Linear is traditionally used in film photography, circular - in digital photography, as it is designed specifically not to create problems with autofocus. When you attach the filter to the lens, you will find that it can rotate, changing the direction in which the light is polarized.
When shooting in direct sunlight, you may experience a phenomenon where your photos will look harsh and overexposed, as if you were in the sun without sunglasses. A polarizer allows light to pass through only in a certain direction, while attenuating light from other directions, thus reducing glare. Take a look at the photos below, the first photo was taken without a filter, you can see that the light is reflected very strongly from the road, as a result, the light areas are overexposed. This impairs the perception of small details and reduces the overall quality of the photo.
Now take a look at a similar photo taken with a polarizing filter. Road glare is significantly reduced and the perception of light details is improved. For example, the left shoulder now stands out much more. as the contrast between him and the road increased. Overall, photos taken with a polarizing filter look much better.
A polarizing filter also removes haze from a photo, which is a great effect when photographing a distant subject or scene. This makes the sky bluer and the colors more vibrant and saturated. Take a look at the two photos below. The first was taken without a polarizing filter, the second with a filter.
How to Use Polarizing Filters
The effect of a polarizing filter is maximum when the angle between it and sun rays is 90 degrees. This way you get maximum effect, however. You should be careful when using the filter with wide-angle lenses. Since they cover most of the space, the direction of the rays will be very different from 90 degrees. As a result, we may get a change in the color of the sky from dark to light in the image, which is undesirable
The filter has the least effect when the sun is behind the lens. The photo below shows this. The left photo was taken without a filter, the right with a filter.
Polarizing filters tend to be quite dark, so make sure the shutter speed you use is fast enough to shoot handheld. Typically, polarizing filters are used in bright sunshine. so this shouldn't be a problem. If the shutter speed is still not fast enough, increase the ISO from 100 to 200.
It is important to make sure that automatic white balance works correctly with a dark filter. It's better if you set it to "Daylight" to avoid automatic errors. A polarizing filter only works well in sunlight, so if you're shooting at night or on a cloudy day, remove the filter from the lens.
Be careful not to get carried away with the effect and get too dark sky in the picture. Take a look at the photo below, the result of using a polarizer is quite extreme and looks unnatural. Sometimes this effect is justified, but in some cases it is better not to use a filter.
An illustrative example is presented below. Here, the reflection from the ground in the left photo adds detail to the image, unlike the right photo, taken with a filter, where this area is dark.
A polarizing filter is often used to remove reflections from glass and water. They are incredibly effective in this regard and are often used when photographing bodies of water, as they make the water “transparent”.
Finally, it is very important to choose the correct angle of rotation of the filter. take a look at the two images below. In the photo on the left, the color of the sky is uneven; in the photo on the right, the angle of rotation of the filter is chosen correctly and the sky looks much more natural.
What to look for when buying a polarizing filter.
A: Make sure the filter diameter matches the lens diameter. Look at the front lens or inner side lens caps.
B: If you have a digital camera, make sure the filter is circular.
(from the translator: a circular filter is designatedC-P.L.circularpolarizing. Currently in modern SLR cameras professional level all autofocus sensors are cross-shaped, and the autofocus system is more advanced, so this advice loses its relevance)
Q: Use a filter best quality that you can afford. It's stupid to buy a $1500 lens and then screw a cheap, low quality piece of glass onto it. Personally I use a filter high quality Hoya.
D: Buy a filter case. When not using the filter, place it in its case to protect it from dust and scratches.
Many people have heard about polarizing filters, which are already the stuff of legends and to which mystical properties are attributed. Why do you need a polarizing filter and how to use it?
Personally, I don’t leave the house on a clear sunny day without a polarizer, and here’s why.
The polarizing filter has been the secret of professionals for a long time. Of course, you can achieve a similar effect by spending a few hours in Photoshop. But I prefer to save time, so I use filters while shooting. In addition, in some situations, Photoshop will not save you, and you will no longer be able to repeat the shot.
A polarizing filter is made of a special material that allows light to pass through only with a certain polarization. Without going into too much physics, light is polarized when reflected from non-metallic surfaces, such as glass or water. By turning the filter rim, you choose whether to let such light through or not. This means you can filter the reflection, something you can't achieve in Photoshop:
Without a filter, the bottom would not be visible due to reflection and the photo would turn out boring.
Polarizing filters vary in cost and differ not only in transparency, but also in the degree of polarization. A good filter will be transparent to unpolarized light (you'll lose a couple of stops, no more), and completely opaque to polarized light. Here is an example of a good B+W filter (the light from the LCD monitor is polarized due to the technology):
Rotate the filter:
Our attentive readers, as usual, were wary when they saw the title photo. How does a polarizing filter make the sky blue? It filters out reflections, what does the sky have to do with it?
! It turns out he has something to do with it ;)There are a lot of aerosol particles in the air that polarize the light, reflecting it, and thereby illuminate the sky in your frame, forming a veil. A polarizing filter removes this veil, blocking light reflected from particles and the sky becomes blue and the clouds have contrast. This works best in clear weather in a direction perpendicular to the sunlight:
Below the picture is a link to a large photo taken with a polarizing filter. It so happened that the filter had a diameter of 77mm, but I had a 50mm 1.8 prime, which has a much smaller diameter. A polarizing filter is an expensive thing, so I don’t buy filters of different diameters, I just put a large filter on the lens and take pictures.
Today we will talk about light filters. These are little photographer's assistants that cling to the lens. Of course, in our digital age, post-processing works wonders, but in some cases filters will be indispensable assistants. Before the advent of digital, there were a great many different filters, they helped to do what programs do now, and now the need for most filters has disappeared. But nevertheless, there are 3 common filters that are still relevant:
- Protective filter - UV or ultraviolet filter
- Polarizing filter
- Neutral gray filter
Let's look at these three types in a little more detail. In order to understand what is what and why.
Protective filters - UV and company.
In general, there is confusion with this category. Technically, there are 4 different filters in this group. Neutral, UV, SkyLight and Haze anti-haze filters. The purpose of this group of filters is one - to protect the lens from mechanical damage, ultraviolet light (matrices and film are much more sensitive to it than our eyes) and from “haze” when shooting at long distances. The most common are UV and Skylight.
Skylight usually costs more, and sellers like to present it as “the best,” but in fact, its pinkish glass was intended to add “warmth” to the frame taken on film. In digital this effect is practically reduced to zero by the presence of such a thing as white balance, so it makes sense to overpay for Skylight for digital camera I personally don't see it.
No matter what manufacturers write or store salespeople say, the main purpose of protective filters is purely mechanical protection of the lens. UV filter allows
- Protect the lens from dust and sand
- Protect the front lens from scratches, fingerprints, impacts, etc.
- Protect the “edge” at the end of the lens (for screwing on filters) from bending in case of accidental impact on the lens
- Protect the front lens from precipitation, splashes of salt water at sea, etc.
Protective filters are the most inexpensive, and you can buy a filter for each lens, but do not forget that any filter is an obstacle to the path of light. Therefore, you should not chase after cheapness and buy a protective filter good manufacturer, made of high-quality glass with high light transmission. By the way, for the same reason, when using, for example, a polarizing filter, it is better to immediately remove the protective one, rather than arrange a pyramid of filters at the end of the lens.
Polarizing filter
Polarizing filter, also known as “polarizer”, is a thing in highest degree useful, in fact a must have for any self-respecting photographer. What is he doing? IN general case it removes glare and reflections from surfaces other than metal. On a sunny day, it can also “darken” the sky, making it more textured, although in reality it simply removes the reflection of light from small droplets of water and moisture present in the atmosphere.
In addition, a polarizing filter “steals” light. It can steal from 1 to 2 stops from you, depending on the quality of the filter itself. Accordingly, when using a polarizer, you may need to introduce exposure compensation, and in low light, a tripod will simply be necessary.
In addition to all of the above, a polarizing filter can significantly improve the colors in a photo, making them immediately the same as you often make them later in Photoshop or another graphic editor. The reason is the same, removing reflections from some objects. In this case, reflection does not mean what we see in the mirror, but any “reflection”.
Some examples from the series without a filter and with a filter
Below is a classic example of using a polarizer, made by Hoya back in the last century.
Polarizing filters are either circular or linear. There is no point in describing the difference between them, since for a digital camera with autofocus and other functions, manufacturers clearly recommend a circular one. A circular filter is a system of two mandrels, one of which (with glass) rotates freely relative to the second. By rotating the mandrel with glass you achieve the desired effect.
The unfortunate thing is that a good polarizing filter is not cheap. And given that the diameter of lenses usually varies (and the diameter of a suitable filter, respectively), you will either need a separate filter for each lens or a bunch of adapter rings. The easiest way out of this is to understand which lens you use most often in those situations in which a polarizer will be useful to you and buy a filter specifically for it.
In addition, inexpensive Chinese NoName filters have now appeared on the market, which are not worth buying at all. I wouldn’t recommend looking at filters cheaper than 1500 rubles (~$50) at all - you risk simply throwing away money.
Some tips for using a polarizing filter:
- Do not use a polarizing filter over wide angle lenses, since it will be difficult to obtain uniform polarization. The limit lies in focal length approximately 28mm. For the same reason, it is better not to use it when shooting blanks for panoramas.
- The greatest effect can be achieved when the light source is at 90 degrees relative to the photographer-subject line. If the sun is in front or behind, the effect will be minimal.
- In diffuse lighting, a polarizing filter will be useless. For example, when shooting a landscape on a cloudy day
- If you stack a polarizing filter on top of another, you can end up with significant vignetting and further reduce light transmission
- Do not take photos through glass or other transparent surfaces, as you may get unpredictable effects, as in the photo below.
Neutral gray filter.
A neutral gray filter, also known as Neutral Density or simply an ND filter, can be either simple or gradient. The purpose of this filter is to help the photographer make the desired exposure. Sometimes it is necessary to minimize the amount of light entering the matrix through the lens.
On the one hand, this can be done by “clamping” the diaphragm. But in this way it is not always possible to achieve the desired result, and your hands are tied by a clamped diaphragm. Using a neutral gray filter frees up your hands. We can reduce the amount of light by the desired amount and still safely choose any aperture.
Why do you need to reduce the amount of light? The most telling example is the “mystical water” effect. Surely you have seen pictures where the water in the sea or, for example, a waterfall, looks like a “milk river” and not like drops frozen in flight. This effect can be achieved with a long shutter speed. How do you shoot at a shutter speed of, say, a second or two on a bright day? This is where an ND filter comes to the rescue.
We put required filter and we get the opportunity to “shoot during the day as at night.”
In addition, we get the opportunity
- use wide apertures in bright light
- add blur to moving objects, “blurring” them
- get a shallow depth of field in very bright light.
A gradient filter is a type of ND filter, only the dimming is a gradient, that is, increasing (or decreasing :)). When is this useful? Well, for example, when shooting a scene with a very high light contrast, so as not to get a “knocked out sky”.
The dark part of the gradient is located in the sky, the light part is on the ground. As a result, we get the sky “not illuminated” since much less light falls on the matrix in this place. True, the gradient filter has one drawback. It will ideally help only if we have a more or less clear and even boundary of illumination separation.
How to choose the right neutral gray filter? Neutral gray filters are again characterized by stops; the most popular are 1, 2 and 3 stop filters. Although there are 10, it's only up to you and your wallet.
