[Photography Skills] What are the misunderstandings in photography?

The second thing about photography is that it contains many elements. You can regard it as both an art and a science. To some extent, creating with a camera is the same as creating with a brush, but photographers who attach great importance to equipment in photography must understand the characteristics of cameras and lenses. However, because photography is so profound and involves so many elements, many people will have many misunderstandings and fallacies about it, and many friends who are beginners in photography are misled unconsciously. Therefore, we specially concocted this article to share with you some photography problems that are often misunderstood. Myth 1: The higher the contrast of the lens, the higher the resolution. Some photographers will find that their images taken with a certain lens have high contrast (generally called "hard") or look sharp, so they blurt out that the resolution of a certain lens is first-class. Once you look at a photo with weak contrast (which is often said to be soft), the image resolution of the channel lens will be very poor. This statement seems a bit arbitrary. In fact, resolution and contrast are two different things and should not be generalized. Of course, there are also some related places. What is resolution? Resolution is actually data obtained through some standard tests. It uses a black-and-white line chart and shoots with lenses with different apertures. However, the most standard data should be read by the machine. However, some magazines or experiments use film imaging for artificial judgment, which seems to have some objective factors, such as film processing or human eye limitation, but it is generally acceptable, because at least the same lens can be found in different situations (different apertures or focal lengths). Generally speaking, the more lines that can be analyzed in the same range, the higher the resolution, that is, the sharper the lens. What is contrast? Although contrast does not represent resolution, it is not irrelevant, but it cannot be said that high contrast leads to high resolution. Contrast actually refers to the ability of the lens to express darkness. An image must have two contrasts, bright and dark. High contrast means that the separation of light and shade is obvious, and there may not be too many layers); In the middle. Low contrast means that the light and shade are not obvious enough or bright enough, but there are many layers, which may make people feel dull. For color or black and white images, the definition of contrast is the same. Most people misunderstand that high contrast is good, yes, high contrast is indeed more vivid and brisk, but without rich layers, the high resolution just now loses its meaning and will hinder the overall detailed performance. But contrast is a very subjective thing, there may not be a standard, but a more comprehensive lens will be more popular. Moreover, the current films also have good contrast and layers, and there are different choices, such as films specially designed for portraits and films specially designed to restore accurate colors. Photographers don't need to pursue them blindly. Myth 2: adding 1B sky lens is better than UV filter. Whenever we buy a new lens, we will consider buying a filter to protect the lens. Generally 1B skylight and UV, the former is more expensive than the latter. Some people say that UV is just a piece of glass, but 1B will make people look more beautiful or have more accurate colors, so we will choose 1B, but this seems to be the case. Officially, 1B skylight filter is a color filter, which is one of the standardized color correction filters. It can cut off light waves below 360nm (from blue light to ultraviolet light) and slightly absorb light waves around 550nm (that is, green light). In short, it is used to reduce the blue phenomenon and the green reflection of leaves when shooting in mountainous areas or seaside, so it may be useful to take portraits on green grass. But shooting in direct sunlight, this 1B filter is completely useless, in other words, it is just a piece of glass. UV filter is used to shield ultraviolet rays invisible to the naked eye, so it has no effect on color (generally, color film latex film can not show the color of UV at all). However, according to the suggestion of the factory, its biggest function is to improve the blur of shooting at infinity, but to be honest, the weather is the final decisive factor. If there are many dust particles or high humidity in the air, it is inevitable to add many pieces of UV. In this case, is it best not to add any filters? Yes, it is absolutely good in optics, because adding a piece of glass may be counterproductive, but it may not be detectable by the naked eye. After careful weighing, it seems more important to buy a piece of glass to protect the front lens than a little optical loss. But 1B is still UV, go ahead. However, it is enough to spend some money to buy a multi-layer coated UV, which can protect the lens and reduce the optical loss. It is worth it. Myth 3: Professional films are better than amateur films. Some photographers often have the illusion that the quality of professional film must be better than amateur film, but they often find that the fact is not so obvious, so they attribute it to the camera, lens, exposure meter and so on, or even themselves. This seems a little pathetic. Professional films do have advantages over amateur films, but that doesn't mean amateur films are necessarily inferior. In fact, we just want to say that professional films are specially designed for professional photographers. To use them well, the method is simple. Just learn how to be a professional photographer. What is needed is not necessarily professional equipment, but skills, especially skills in dealing with films. You might as well try to buy some professional slides to try. You will find that there will be a refrigerator in the exhibition place, and then pay attention to the instructions on the film. In addition to the service life, there is also a suggested storage temperature, which is generally around 12 or 3 degrees. Professional films are fresh enough. If it can be saved in the suggested environment, the film will get the expected effect. However, it feels strange to handle the film at will, and then go to Shop A and Shop B to watch it for a while, which can ensure that there is no different color expression every time. Of course, there are many methods to deal with films, such as exposure coefficient and reciprocity rate. , or refer to the instructions in the manual. Amateur films, except expire date, have no other explanation, but generally have a long and stable shelf life and high tolerance, which seems more reliable for ordinary users. Myth 4: Flash shooting must use X-sync shutter. Many Chinese and foreign photography books have also mentioned the X-sync shutter, and even the term the fastest flash synchronous shutter. However, many beginners of photography have a misunderstanding that a certain shutter should be used rigidly when flashing. In fact, the so-called flash synchronous shutter or the fastest flash synchronous shutter generally refers to the shutter that can be used for flash shooting. The fastest shutter means that the shutter speed higher than that shutter speed cannot be used for flash synchronization, otherwise a clear full-film image cannot be taken. This problem exists in cameras with shutters behind the mirror. Each camera has an independent design, so the highest synchronous shutter is not the same. When using flash, you can take photos with flash effect at any position under the highest synchronous shutter, but the slower the shutter, the longer the live light exposure time. For example, when shooting indoors, if you shoot with the highest synchronous shutter flash, the background may not be exposed enough, making the foreground of the subject white and the background dark; If you shoot with a slow shutter (even the so-called slow synchronization or night portrait mode in portable cameras, etc. ), you can get a photo with a more lively atmosphere. In addition, when using the slow shutter, you can even choose the synchronous flash of the front or Hou Lian. You can adjust the flash as soon as the shutter is opened and flash before the shutter is closed, which can create a special shooting effect. Myth 5: Macro lens can only take close-ups? Macro lens is specially designed for very close shooting, but some people say that normal shooting will deteriorate or superstition can only be used for remake or macro shooting. In fact, according to some optical tests, the resolution of the macro lens is excellent in most apertures, whether shooting at the ratio of 1: 1: 2 and 1:50. When tested at 1:49 or 1:50, the resolution is much higher than other non-macro lenses with the same focal length. However, the biggest problem of macro lens is that the focusing design is specially designed for short distance, so rotating the focusing ring at a distance of tens of centimeters to infinity may be less than 45o, which may greatly reduce the accuracy, but the current AF lens has high accuracy and may make up for this problem. Therefore, it is absolutely no problem to shoot scenes or even portraits at a normal distance with a macro lens. F/2.5 or f/2.8 aperture may not be fully utilized, because light leakage at four corners is inevitable, but it can be solved by collecting the first aperture. On the contrary, when shooting macro, fine aperture is easy to cause diffraction, so f/8 to F/ 165438. However, some users of the macro mirror will know that the resolution of the macro mirror is very high, and the photos taken look a bit "difficult to jump", but everyone has their own preferences and many choices, whatever you like! Myth 6: The statement that the incident exposure meter is more accurate than the reflective one is not comprehensive enough. Objectively speaking, both are equally accurate, but for those who only use a single measurement method, it is understandable to believe that one is more reliable, because both have their own operation methods and measurement methods. However, in the case of reflective exposure meter, it is a little more troublesome than incident exposure meter, because the limit of 18% gray level is often considered. Incident exposure meter can directly measure the luminosity projected on the subject and directly obtain the aperture value. However, the built-in reflective exposure meters in our camera are convenient, because they don't need to go to the front of the main body to measure, and most of them are TTL (through the lens), which directly accounts for exposure factors such as lens loss and filters, reducing the occurrence of errors and being easier and more reliable than the incident type. However, the color of the subject and background (such as black or white) will cause measurement errors, and the only way is to compensate for exposure. As long as you practice more, it is not so difficult to get the right exposure. The projection type itself has some advantages over the reflection type, but it is more troublesome to use. If you don't mind bringing an extra exposure meter, this is fine, but you must remember to take into account factors such as the filter in front of the camera. For example, NikonF5 has a reflective exposure meter with 3D RGB, which means there is still room for reflective metering to jump out of the cabinet frame. As long as the limit of 18% gray scale is solved, its accuracy is beyond doubt. Myth 7: Sealing is the most reliable against moisture. In the rainy season, the photographer's mood is the most sad, because his beloved equipment is reimbursed at any time, and some people buy all kinds of moisture-proof products, such as dehumidifiers and dehumidifiers. Once it rains, I'd rather hide the camera lens and become a humidity allergy freak. So I may not be able to make a film all summer, which can be said to be very sad. To be honest, the climate here in Hong Kong rarely waits until the RH is below 60%, let alone the rainy season. However, turning off all equipment may not be completely moisture-proof. Many people will have experience, and the "old" lenses placed in a sealed box will be inexplicably moldy. In fact, it is necessary to prevent the lens from becoming moldy, not damp but bacteria. To prevent the lens from moldy, we must first understand why it is moldy. Humidity and darkness are the favorite of mold. However, this kind of bacteria is scattered in the air and cannot be prevented. If there is mold in the sealed moistureproof box, if moisture-proof beads (usually silica gel) are added, it can have a certain dehumidification effect (but it is not permanent and will fail after saturation). Some moisture-proof devices on the market can suck water into the box, although the water absorption effect is very good and obvious. Therefore, many people would rather have time to take out the lens to play or use. Seeing the light can greatly reduce the chance of mildew. Generally, in an air-conditioned room, as long as the air is ventilated and the humidity is low, the chances of moldy lenses are very low. If you really want to hide the equipment for a long time, it is best to put a proper amount of moisture-proof materials in a low humidity environment and put them in a sealed box. Remember to clean the lenses to avoid bacterial growth. It is said that some electronic moisture-proof devices also have certain functions, but the price is very expensive. Myth 8: Always wipe the lens. There are many instruments and even lens wiping on the market. Do lenses need to be polished frequently? The average photographer loves his own equipment by nature. When they see a little dust on the mirror, they feel scared and are eager to buy something to clean the lens. Some people will use the air pump to sweep away or blow away dust particles, or even wipe them with lens paper and medicine, but this is not good. Unless the stains on the mirror surface, such as fingerprints, are difficult to clean, don't wipe the lens surface rashly, because this may stain the mirror surface or part of the coating may fall off, but the coating is quite stable now, but it is still too dangerous. It is recommended to add a UV or IB skylight filter to the lens for protection. Even if it is dirty, you can wipe it at will, or even replace it with a new one, which is more than lensing the lens. If it is really necessary, be careful when buying lens paper or lens cleaner, and avoid using alcohol-containing cleaner, because it will damage the lens. When using, do not drop the cleaning agent on the mirror surface. If the cleaning agent flows into the lens or the edge of the lens, it will also damage the lens. So the best way is to try to avoid staining the mirrors at both ends. If you get dust, gently blow it away with an air pump. If you get fingerprints or oil stains, you can wipe them with a high-density cloth or polished leather. If there is mold or water vapor condensation inside (such as entering and leaving air-conditioned places), it is best to return it to the original maintenance center for treatment. Myth 9: The focal length of 50 mm is equal to the human eye. People often say that the focal length of 50mm is a standard mirror, which is also called the visual effect similar to the human eye. It is often said that the image taken with 50mm is the most real and lifelike. However, if you look at the viewer carefully, the size of the image you may see is not the same as that of the naked eye, and you will find that the image under the 50mm lens will be wider than that received by the brain. From the perspective, the 50mm lens is only 46o, but the human eye can approach 120o, but why is what the human eye sees not as wide as the 50mm lens? The problem actually lies in the plane size of the image and the difference between the lens and the crystal of the human eye. The place where human eyes receive light is on the retina, and the place where photoreceptor cells gather is limited to one point, that is, the yellow point. Cone cells that perceive color are less and more concentrated than rod cells that perceive black-and-white vision. As a result, you will find that when you look at something (such as reading a book), you can only see the central part in the study. Other words outside the circumference may not be clear, but the film is different. As long as the lens angle is covered and the main body is flat, the whole plane will be clear, because the photosensitive drugs on the film surface (24X35mm) are equal. On the other hand, the image taken with 50mm is no different from the real thing in scale. As long as the image is enlarged to the same size as the real thing, it is actually the same as what you see in front of the real thing, but this is not only possible with a 50mm lens. Where is 80mm, 100mm,180 mm ....................................................................................... It may be closer to what the human eye sees from the viewer, but it depends on the distance of the subject. Remember: the human eye sees the physical size of 1: 1, but what the viewer sees is the reduction effect. Also, the focal point or clear plane distribution of the 50mm lens is different from that of the human eye, so it may look a little close to the human eye, but it can still be said that the deformation of the 50mm lens is not serious and the framing range is moderate. Myth 10: The focal length of the lens will affect the viewing angle. Some photographers often say that a 20mm lens has a sense of perspective and a 300mm lens has a sense of depression, saying that these are all because of different focal lengths and different perspectives. In fact, perspective has nothing to do with focal length, and perspective refers to the contraction effect of light. For example, when shooting the whole building from the ground with a wide-angle lens, the lines on both sides of the building will shrink upward instead of parallel. Generally speaking, there are three main factors that affect perspective: constant distance. If you keep the same position and angle with the subject, but shoot the same subject with different focal lengths, the field of view of the photo will be different, and the subject will have different magnification, and the longer the focal length, the greater the magnification; However, the perspective has not changed at all. If you don't believe that many photos taken with different focal lengths can be enlarged or reduced to the same magnification, then the proportion of the subject and the background is very similar, that is to say, the perspective is also similar. Changing the distance between the camera and the subject has nothing to do with the focal length of the lens, but the same lens and the same focal length will have different perspective effects if the camera is shot at different distances from the subject. Or, when there are multiple cameras shooting the same object with different focal lengths, the shooting distance is changed so as to shoot objects close to the same size. Therefore, the 20mm camera will shoot more backgrounds, while the 100mm camera will have an effect close to human vision, while the 200mm camera may shoot "compressed" or close photos of the background and subject. The angle between the camera and the subject is another factor that affects perspective. If you shoot a standing portrait from a low angle with a wide-angle lens, it will appear that the upper body is short and the lower body is long, but shooting from a high angle will have the opposite effect. If you shoot horizontally towards the subject, this distortion of perspective will not appear. You may not misunderstand the above photography problems in the future, but photography is still a changeable thing, and there are still many places worth discussing. If there is an opportunity in the future, maybe I can share it with readers again.