Sooner or later, every photographer comes to a moment when the elementary knowledge of his technique and sense of the frame is no longer enough and he wants to add to his work some artistic elements, techniques that open up new horizons in work.
If you have been engaged in comprehending the intricacies of photography for several days, then, most likely, you have already encountered the problem of too much light in a particular frame (especially when you would like to increase the exposure). This is what a neutral density filter serves for. All they do is reduce the amount of light entering the lens and nothing else. Of course, if you use a cheap fake, then the color correction will appear. But if we talk about high-quality ND filters, they do not change the color of the image, as it should be. And all because their glass is covered with a special spraying of metal particles, while on both sides each filter has a perfectly smooth polished surface and multi-coating.
Neutral filters have a simple and user-friendly gradation. For example, the ND2 filter transmits 2 times less light into the lens, ND4 - 4 times less, ND500 - 500 times less, etc.
In addition, all filters have a special thread on the outside, so they can be combined, providing the necessary dimming. For example, if you have only two filters ND2 and ND16, winding them both at the same time, you will be able to increase the shutter speed from 1 second up to 32 seconds. This is very convenient and allows you to get different values with just a few filters, only slightly setting the ISO and aperture mode on the camera.
However, do not forget about such an effect as vignetting (darkening at corners of the frame), which becomes critical on full-frame, because even with two filters, for example, on a 16 mm len, we practically exclude the edges of the frame in the circle of the second filter.
Using best ND filters it is possible to shoot even during the day in the bright sun at longer exposures.
This means blurring the movements in the frame, opening the aperture wider, while reducing the depth of field etc.
Composition can be disturbed by passers-by and other moving objects. By increasing the shutter speed, we simply remove the moving objects from the frame. Or we blur them to the desired degree, playing with the shutter speeds, depending on our creative idea. For example, having an ND1000 filter, we can thus adjust the exposure during the day in order to shoot two lovers in the crowd of the city (who will have to stand still embracing for a while), while the crowd around them will be exposed with a barely noticeable train, and it will seem that for these two time has stopped, and the rest of the world simply does not exist and it is very emotional.
These are waterfalls, and lake/river surface, and heavy rain, and sea waves - everything that is connected with water! Here using ND filter opens up great prospects. Through various manipulations with exposure, we can make a water surface as smooth as glass. Or, if the sea or lake is not calm, using a slow shutter speed you can turn it into fog or haze. Such an effect is in the top for ND filter photography. If, on the contrary, you intend to emphasize the dynamism of the water flow, then the exposure can be lengthened only slightly (up to 1-2 seconds, but you need to experiment) so that the water smears a little: you will get the feeling that it is moving very quickly.
Stormy stream. Usually 3-4 seconds are enough. If you expose for longer, then the water stream is likely to turn into a kind of monolith.Slightly blurred cars in motion in the city. Shutter speed approximately 1/2 second. If more, then cars will be too blurry (if you do not achieve exactly this effect).
Slowly passing clouds. Here you need an exposure of 10-15 seconds, then the movement will be transmitted very beautifully. But you also need to look at the speed of passing clouds.
Wave off the coast. Here different options are possible, depending on what effect you want, from the brightness of the light, the strength of the sea surf, etc. If you need a barely blurred wave, then the shutter speed is usually up to 1 second.
It is a flexible version of the standard ND filter. The advantage of this option is that it covers a whole range of different densities, up to 7 stops. It consists of two filters connected to each other, when scrolling, the volume of light entering the matrix changes. The circular shape of the filter creates some obstacles - for example, wide-angle lenses can experience severe vignetting, while fisheye lenses do not use such filters as they require a flat lens surface.
The main advantage of the variable ND filter is the ability to select any value for the desired volume of light.
This is one filter that we can twist to get different shading values. If at low ND values with such a filter, the image quality is acceptable, then with higher darkness, vignetting is so strong that it takes almost half a frame, and pictures can be spoiled immediately. This is a problem with any variable density filters.
A gradient ND filter is suitable for several situations. The principle of its work consists in a soft transition from light to dark areas of the frame. The number of stops in the upper part of the filter can be from 1 to 4 stops, and the transition between the dark and light areas of the filter can be either hard (clear border) or soft (more blurred border). Filters can be round, square or rectangular. They also come in different sizes (for larger lenses).
The most common use of a gradient filter is to darken the light part of the frame, such as the sky. The human eye is able to perceive 14 EV (steps of exposure) of light, so the sky and earth can appear to be equally lit. However, modern cameras are only capable of transmitting 8-9 EV of light, so when the sky is lighter and the foreground is darker, you need to use a filter to equalize the sky and the ground in exposure.
Using a gradient ND filter, it is possible to shift the highlight information. Exposure should be measured in the foreground before installing the filter, and a filter with a density that can compensate for light in the background should be selected. Otherwise, the camera will take into account the area of the frame covered by the filter, and you will get an overexposed photo.
Another ND filter option is a reverse gradient kit. It is used for specific landscapes, but if you are smart you can find even more uses. This filter is most often used for sunsets and sunrises to block out intense light along the horizon and bring out the foreground. From the darkest part of the filter in the middle to the top edge of the filter, the density is gradually reduced by about one exposure stop to reveal the sky. It is best to measure the exposure in the foreground before using the filter.
Color correction filters, or conversion filters, help to obtain accurate color reproduction when shooting in difficult lighting conditions, when, for example, the camera's automation cannot cope with the white balance. The filter introduces a shift in color temperature, this shift is measured. Each filter has its own offset value. For an accurate selection, you will need a colorimeter, special tables or extensive experience.
Color-enhancing filters allow you to highlight one favorite color: blue, red, green. Filters emphasize a specific color without changing the tonality of the photo.
Softening filters. The clarity of the image remains sufficient, and at the same time small details (wrinkles, spots on the skin) are not striking. There are different variations of Soft Filters.
There is a large number of creative filters that provide a wide variety of special effects. Several of the filters listed already provide an opportunity to get an idea of what original effects can be obtained with their help.
Star (ray filter) allows you to create interesting compositions in frames with point light sources, with rays forming "stars" with it. Rotate the filter for dramatic effects. The size and brightness of the star's rays depend on the light source, its size, shape and brightness. The finest lines are applied to the lens of this filter using laser technology, the number of directions of which determines the number of rays of the star. Lines in one direction create a two-ray star, there are filters that create 4-, 6-, 8-, 12-ray stars and more.
When using 8- or 12-ray star filters, be careful as a large number of rays can block a large portion of the image. Although Star filters produce symmetrical beams, it is possible to create a non-symmetrical picture. Be careful with the depth of field - do not allow the finest lines drawn on the filter lens to appear in the resulting image.
Triangle triples the image. Rotating the filter changes the position of the object. There are also 2-, 4-, 5-, 6-section filters, vertical and parallel prisms.
Close-up option by screwing onto a regular lens, you can take macro shots with conventional optics. Used throughout the entire zoom range, and you are not limited by the distance to the object.
The image in black and white photography depends on light, shadow, contrast, and filters here are clearly not superfluous. Due to the peculiarities of human eyes, as well as the imperfections of films (and matrices too), for better tonal reproduction, it is recommended to shoot most scenes with light filters. For the correct transmission of tones, for example, a yellow-green filter is applied during the day. When shooting in the evening, when the illumination from incandescent lamps gives predominantly red-yellow rays, a green filter is applied . It corrects the lack of intensity of blue-blue rays. Yellow, orange, and red filters increase contrast.
Filters will lighten objects that are close to the color of the filter, and objects that differ from the filter in color will appear darker in the image. The blue sky when shooting with a yellow filter will turn out to be dark, and with a red filter it will be almost black. But green leaves reflect light not only in the green part of the spectrum, but also in the infrared range. Using a red filter will make green foliage lighter.
The most telling example is the effect of "mystical water". Surely you have seen pictures where 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 obtained with a long exposure.
We put the necessary filter and get the opportunity to “shoot during the day as at night”.
In addition, we get the opportunity to:
Gradient filter is a kind of ND filter, only darkening goes with a gradient, that is, increasing (or decreasing. The darker part of the gradient is in the sky, the light is on the ground. As a result, we get the sky "not overexposed" since much less light falls on the matrix in this place. True gradient filter has one drawback. It will ideally help only if we have a more or less clear and even border of separation by illumination.
The answer is ambiguous, but you need to choose a good manufacturer. This is especially true for the polarizing filter. First of all, you should pay attention to the brands of Hoya, Marumi, Kenko, B + W, Tiffen etc.
The main thing is not to look for cheapness. Remember that it will certainly affect the quality of your pictures.
Light filters for optics are selected based on the diameter of the front lens. It ranges from 25 mm to 105 mm. The filter diameter is always indicated in its name. If there is a large choice of optics with different-sized lenses, the photographer has the right to buy a light filter for the largest available lens and use adapter rings to install the filter. However, it is better to buy filters for the "native" size.
Most often, filter lenses are presented in the size of 49 mm, 52 mm, 55 mm, 58 mm, 62 mm, 67 mm, 72 mm, 77 mm and 82 mm.
Separate requirements for light filters are imposed by "ultra-wide"options. In particular, many of them are "friendly" only with filters in a thin frame (Slim), which is done in order to eliminate the effect of vignetting. And due to the convexity of the front lens, special slots for installing a light filter are provided in the design of individual lenses.
Ultraviolet filters protect the outer lens. It is most often used to protect the outer lens of expensive lenses from scratches, dirt and dust from getting into the lens. Sometimes, an inexpensive UV filter saves the front lens even in accidents. However, in addition to protective functions, the ultraviolet filter also cuts off a certain amount of ultraviolet radiation (removes excessive blueness) and makes the picture a little more contrast. This is especially noticeable when shooting high in the mountains or on the seashore.
The ND filter is not an easy accessory. Use it correctly:
The larger the filter diameter, the more expensive it is. Generally, the higher the price of the filter, the better it is. Prices here can vary greatly. The filter that you will use more often than others usually should be more expensive.
Keep the filter clean, as greasy spots, dust, dirt, all of this does not have the best effect on photographs. It is still better to purchase a special cleaning kit. Do not carry the filter in your pocket, just keep it in the factory packaging. There are also special soft covers for light filters.