PS is irreplaceable! The Use of Several Filters in the Digital Age

In the film era, the sensitivity of various films is fixed, and the color reproduction characteristics of color films are also fixed. Therefore, filters are necessary accessories for professional photographers. But in the digital age, some filters are no longer necessary, and some filters are still working. Filters that can be almost forgotten-color temperature control filters In black and white photography, various color filters are used to control hue and contrast, while in color photography, various filters are needed to control color temperature. Yellow color filter is very commonly used in black-and-white photography, which can absorb most of the blue-purple light, make the photo effect natural and moderate, and highlight the clouds. It is essential to shoot scenery, flowers, bonsai and still life. It can simulate the hue of dusk in color photography. There are many color temperature compensation filters used in color photography, forming a complete series. Only experienced professionals can accurately choose different filters to achieve different color correction purposes. In the era of digital photography, many functions of traditional filters have been replaced by cameras or later software. Contrast and hue can be freely controlled by camera parameters or post-processing. The white balance function of the camera and the later color correction of the software directly replace various color temperature compensation filters. When you need to get a special hue, you can use Photoshop's digital filter with just a few clicks of the mouse. Even if you are a black-and-white photographer, if you create with a digital camera, I suggest you forget the experience of the film era, put away all kinds of color filters, or re-verify the real shooting effect of all kinds of filters before using them carefully, unless you use a special black-and-white digital camera (it seems that only Kodak has ever produced it), because the "black-and-white" mode of a digital camera is a kind of "pseudo-black-and-white"-it reproduces the formed color image through data calculation. Filters that can never be used only-The basic functions of filters used to control exposure (also called grey mirror and nd filters) can also be realized by controlling the camera's sensitivity (ISO). Some cameras even have a built-in ND filter function. Only in extreme conditions, such as when a slow shutter is needed to show motion in bright outdoor light, it is necessary to add a real filter in front of the camera. Filter Photoshop uses subtracter and ultra-low shutter speed to obtain the softness of water, which photographers despise-all kinds of special effects filters, such as starlight mirror, split mirror, hollow mirror and other special effects "magic" filters. Because it is too naive and tacky, it is disdained by real photographers. In the digital age, software can handle all kinds of magical effects, even if it is identified as "kitsch". The filter that can be used at ordinary times-uv mirror In the film age, UV mirror is almost an indispensable additional mirror for SLR lenses (it is almost the same now), because natural sunlight contains a lot of ultraviolet rays, which will form fog on the film. In fact, the composite filter in front of the image sensor of the digital camera already contains the function of blocking ultraviolet rays. Therefore, for digital cameras, UV mirrors are not completely necessary. Moreover, some poor quality UV mirrors will also reduce the imaging quality and form reflection ghost. Therefore, if you are a rigorous photographer who pursues high imaging quality, you can always make the lens "naked", especially when shooting backlight photography and macro photography, you will find photos. " However, the function of UV mirror has changed from light selection to lens protection. After all, the price of UV mirror is much cheaper than that of exquisite professional lens, so if your lens is expensive enough and your UV mirror is good enough, keep it. On the other hand, if your lens is cheap enough and the quality of UV is not guaranteed, you might as well take it off. So, don't talk about the digital age, don't use filters? Of course not, the function of some filters is irreplaceable by other means! The most recommended filter-polarizer is the most important filter in landscape photography. Many photographers know how to use polarizers to make the blue sky bluer and eliminate the reflection of glass, water and metal, but in fact polarizers can do more. Even on cloudy days, polarizers have obvious effects. Although it can't turn the gray sky into blue, it can make the color stronger by removing the reflection from the surface. For example, on a cloudy day, every leaf, every piece of glass and every slippery stone will reflect some light from the gray sky. These reflections obviously lighten the color. Put a polarizer in front of the camera, turn it and you will find that the color becomes stronger. Try shooting the same scene with or without a polarizer, and you will find amazing differences in the final photo. It's easy to use a polarizer, just screw it on your lens, look through your viewfinder and rotate it at the same time until you get a satisfactory result. Sometimes you can't see any change by rotating the polarizer, because the polarizer only works when the direction of light is at 90 degrees with the axis of the polarizer. If the light comes directly from behind you or you shoot the light source directly (sunset), the polarizer will not have obvious effect. But if the light comes from your left or right, or directly from your head (noon sunshine, cloudy weather), the filter will magically remove the reflection, darken the blue sky, eliminate the shadow and saturate the color. This is the filter you must have. Without a polarizer, it is obvious that the color of the picture is dark and the sky and white clouds are not well highlighted. Use a polarizer to eliminate polarized light in the sky. The sky is blue and the clouds stand out. In addition, the color saturation of grass is increased by two polarizers-linear polarization (PL) and circular polarization (CPL). Can meet the basic requirements, but the use principle is different. I won't discuss their differences here, but you really need to know which one suits your camera best. Old-fashioned manual cameras can use linear polarizers (cheap). Autofocus and digital cameras need circular polarizers, because linear polarizers will affect metering and autofocus. Check your user manual to determine what kind of camera you need. If in doubt, buy a circular polarizer, because it can work well on any camera. It is recommended to buy high-quality polarizers, not to use cheap ones. Insist on buying famous brands (Singh-Ray, Tiffen, Hoya, Heliopan, B+W). Most polarizers are a little blue, which can be ignored in digital cameras because of white balance adjustment, but we must pay attention when using film, because it often leaves a perceptible blue mark on photos (especially on slides, the magnification effect is better). In order to avoid "blue", some manufacturers produce "warm color" polarizers. This combined filter is great. The gradient lens, a necessary filter for landscape photographers, can't control the light source, so we have to do some work in front of the lens. It is an inevitable action to take horizontal and demanding landscape photos, plus various suitable filters. In addition to polarizers and nd dimming filters, various gradient filters are important tools for shooting landscapes. Knowing the different ways to use the gradient filter, you can naturally take different scenery photos. The plug-in gradient filter can be fixed on the bracket in front of the lens through a special bracket, and multiple filters can be installed for use together. When shooting outdoors, the light between the sky and the ground is quite different. Due to the limited tolerance of the camera image sensor, in this case, it is impossible to take pictures of the sky and the ground at the same time with normal exposure. If the sky is exposed accurately, the ground will be underexposed and turn black; If the ground exposure is accurate, the sky will be overexposed and become dead white. Especially when it is cloudy, sunrise and sunset, the problem of light difference becomes more serious. In this environment, changing the sensitivity, adjusting the exposure compensation and adding other filters will not help. At this time, as long as a gradient dimming filter is added, the brightness of the sky will be reduced, but the brightness of the ground will not be affected, and the light difference between the sky and the ground will be reduced, so that the level of the sky and the ground can be completely reproduced in the photo. Nowadays, digital cameras are all designed by TTL photometry, and even if a gradient dimming filter is added, no special exposure compensation is needed. In addition to adding a gradient dimming filter when shooting cloudy days, sunrises and sunsets, adding this filter when shooting on sunny days can make the color saturation of the sky higher, make the sky appear bluer and look more relaxed and happy. Without the filter, the exposure of the ground is insufficient, and after adding the gradient dimming filter, the exposure of the ground and the sky returns to normal. Without filters and gradient dimming filters, the sky would turn dark blue. In addition to gradient dimming filters, you can also add gradient filters of other colors to change the color of the sky and enhance the atmosphere of photos when shooting landscapes. Gradient blue is another commonly used gradient filter. On cloudy and bad days, the gray sky is really a big scene. At this time, you can add a gradient blue filter to restore the sky to blue, and enhance the effect of blue sky and white clouds without affecting the color of the ground. If shooting sunrise and sunset, gradient orange is a very useful filter, which can make the monochrome effect at sunset stronger. In addition, many photographers will add a gradient brown filter when shooting cloudy and cloudy subjects to express nostalgia and moodiness. You can even use two color gradient filters at the same time to make the upper and lower parts of the photo appear different colors, making the photo more picturesque. Without filters and gradient blue filters, the sky becomes bluer. Without filters and gradient orange filters, the atmosphere of sunset becomes stronger.