·The filter is great, don’t use CPL as a UV lens
For friends who play photography, it is indispensable to have access to various filters. I believe that when you buy a camera and lens, you will be “recommended” for a UV lens, and sometimes a few CPL and ND lenses. For the filter, some friends are not leaving the UV lens, and for those who have just started using CPL, there is a feeling of finding a new world. But using CPL is the most error-prone filter. Is your CPL really correct?
·CPL bad habits Don’t use CPL as UV, it’s not good to hang up for a long time
CPL is actually very single-purpose, used to remove reflections; there are many effects after removing reflections, which can increase color saturation, make the sky bluer, and make the clouds more distinct. However, the principle of CPL is only to eliminate polarized light, so CPL is not a universal landscape filter, let alone screwed on the lens at all times. Some friends think that it will be better to take CPL for scenery shooting. Therefore, as long as you go out to play, you can screw on CPL. Regardless of whether you really need it, this is actually brainwashed by various advertisements. For CPL, we first need to know which scenarios cannot be used.
Scenes where CPL cannot be used: portraits; unsuitable scenes: night scenes, starry sky shooting.
When shooting portraits, CPL will cause the gloss of the face to be lost or dimmed, that is, the rhubarb face we call often appears, so CPL cannot be used for portrait shooting. In addition, all CPLs have a dimming effect, so it is not suitable to use CPL for environments that are originally dim and require more exposure, such as night scenes, starry sky, etc.
A common bad habit of CPL: never turn the direction.
For CPL, a more fatal problem is that many friends regard CPL as a UV lens, and leave it alone when it is screwed on the lens. Whether CPL is used to eliminate reflections or to darken the sky, you need to rotate the CPL every time you shoot at different angles to get better results. If you only screw on the CPL, sometimes it will not only fail to improve the picture, but it will be seriously counterproductive. Sometimes, the most common consequence of improper use of CPL is not only to darken the sky, but also to cause the color scale of the sky in the later stage.
For CPL, the incorrect position not only can not eliminate polarized light, but also makes the color of the photo look stranger, and CPL has a dimming effect, so the shutter speed becomes slower. For portraits, CPL is absolutely unusable. All in all, CPL is a filter that has a very high usage rate, but it needs to be adjusted at all times. CPL is different from UV, and it is not a once-and-for-all with a lens.
·Clean the lens Oil stains are an important killer of photos
Many friends do not like to clean up the dust on the lens. Sometimes they think that as long as the UV lens is hung and the lens lens is not stained, everything will be fine. In fact, for photos, dust will have a serious impact on photos. Taking pictures through a layer of gray UV lens is like taking pictures through a layer of dirty glass. You may not see anything under a large aperture, but once you use a small aperture or a long exposure, the dust will make the photo look dirty Yes, this effect is sometimes difficult to remove later.
On the other hand, if the dust on the lens may occasionally affect the image quality, then the oil stain on the lens is a more deadly killer, which is more common in fixed lens cameras. When we use a camera or lens, we sometimes accidentally touch our fingers to the lens, especially the card camera, and it is easier to form a layer of oil on the lens. This kind of stain will not only affect the image quality, but also wipe out the coating that the manufacturer has worked hard to develop. The oil stain will cause serious glare, which is even more deadly for the photos.
Of course, like the lens, the sensor needs to be cleaned frequently. And when changing the lens, you must pay attention to the bayonet to change the lens, do not change the lens with the bayonet facing the air vent, and do not forcibly replace the lens in a place with heavy sand. On the other hand, if the camera is used for a long time, you should go to a special repair point to clean the sensor, but for general users, please don’t clean it yourself.
· Exposure to the left or right, reasonable exposure is king
After many friends come into contact with photography, they are always exposed to the principle of exposure to the left or exposure to the right. Many friends have been shooting for a long time, and they will always get used to under-exposure or over-exposure when shooting. Even many friends who have been in photography for many years have this habit, especially exposure to the left. Some friends think that for It is guaranteed that the photos taken by one or two stops of under-exposure and under-exposure can be taken as long as the exposure is adjusted later, so they will be habitually shot “blacker” in any environment.
The essence of photos is to record light information. Under exposure or overexposure in a high light ratio environment, it is for later adjustments to get a wider dynamic range. However, underexposure is meaningless in normal daily shooting. Moreover, even if the camera’s latitude is good enough, there will always be a certain amount of noise in the under-exposed photos, and the colors of the under-exposed parts are generally not well exposed, and it is not good for the color control of the photos.
There are two ways of thinking about exposure, high ISO gets a brighter image and low ISO gets a relatively darker image, and then brightens it later. Compared with the two methods, high ISO can get a brighter landscape, and the noise is much less than the noise of low ISO exposure and then brightened later.
In low-light environments, underexposure is a big killer of picture quality. In low light, whether it is a long exposure or a high sensitivity, the noise will increase rapidly. For noise, the brighter the photo at the same sensitivity, the less noise the photo will have. This is particularly important when shooting in the starry sky. Therefore, under-exposure is a taboo when shooting starry sky; of course, over-exposure will result in loss of brightness and detail, so for low-light environments, the best way is to control the exposure of each part separately. You can take a picture of the sky in a bright state without overexposure, and then let the ground scene be in a normal state without overexposure, so that a photo with the least noise can be obtained through post-processing.
For exposure to the right, brighter photos actually help reduce noise, which has become a basic basis for exposure to the right. However, the latitude performance of the camera in the highlight part is much lower than in the low light. Although the low-light part has very little information recorded by the camera, there is still light information recorded, but once the high-light part overflows, it will completely become a data overflow. Therefore, the high-light part will be accompanied by color saturation regardless of overexposure. There is no way to recover once the highlights completely overflow.
Therefore, to expose to the right actually means to make the photo as bright as possible on the basis of ensuring no exposure. If you use exposure compensation and always add one level of exposure for shooting, then the color of the highlights will definitely be lost, and the highlights are hard to recover.
In any case, exposure to the left or right is not as useful as normal exposure in most environments. If you really need to overexpose or underexpose, it must be prepared for HDR synthesis in the later stage, rather than just pre-shooting techniques.
· JPG or RAW, try not to use JPG for post-production
The image recorded by the camera can be directly output as a JPG format or saved as a RAW file. For home users, using JPG is undoubtedly the most convenient, but if you like to post-process photos, and want to be able to rigorous post-processing to get a more ideal work, then you must use RAW files.
The advantages of RAW files compared to JPG The articles on the Internet have long been overwhelming. Here I will briefly summarize the advantages of RAW files compared to JPG. Compared with JPG files, RAW files are equivalent to the original light data, while JPG is the output image processed by the camera body.
Shooting with JPG, because of the addition of a large amount of camera optimization data, such as color optimization, highlight and shadow optimization, etc., it looks more suitable for the aesthetics of the human eye, so it is more flattering. But for the environment that is not suitable for straight-out, or you want to make post-production, these adjustments will greatly reduce the adjustment range of the photo; once you use JPG to adjust, especially the large-scale exposure adjustment, noise, color gradation, and color Exceptions are common problems in JPG adjustments.
For RAW files, adjusting the shadow and highlight details is the biggest advantage over JPG. Using JPG, generally only 8bit, when the photo exceeds the range of 8bit, no software can remedy the highlights and shadows, but in RAW files, we can still rely on post-adjustment to restore details, which is what we often call photo tolerance .
If you want to make post adjustments, RAW files are a necessary basis. Using JPG adjustments, on the one hand, there will be more noise, and on the other hand, the exposure adjustment will be greatly restricted; because of these two factors, use RAW files to shoot, use RAW The later stage of the file is an advanced road that a photographer must go through.
·Bad habits in the later stage, relying too much on HDR and high contrast
When talking about the later stage, there is another problem. Now many friends like to pursue high contrast, high saturation, and high sharpness. If it is more extreme, it is that the later stage is too dependent on HDR technology.
The so-called HDR technology is sometimes misunderstood as a filter effect with high detail, high contrast and high saturation in the later stage. Reasonable HDR is a very good post-production technique, but only relying on plug-ins to treat HDR as a special effect will not only cause distortion of the picture, but also bring a lot of noise and affect the quality of the photo.
In recent years, many photography enthusiasts have admired HDR-style photos, and many textbooks have also advocated HDR technology, and even use HDR for portraits. This style can naturally shine, and there are many photographers who are good at HDR in the world, but HDR is not the only technology in the later stage, and excessive reliance on HDR technology will be a technical disaster for photographers.
In addition, like relying on HDR, many friends, especially those who are new to photography, like high saturation and high contrast photos. Like HDR, high saturation, high contrast, and high contrast can easily cause visual fatigue and make the photos look more unsightly. This is also a bad habit that the camera needs to overcome in post-processing.