文章內容
With the rise of short videos, it used to bemonocularUpthe videofunction, now withcell phoneThe specifications of the film are becoming more and more powerful, and we can get the equipment for filming at our fingertips. As long as the concept is right, maybe we can also realize the dream of being a director and present a film with a unique style.
How to choose among so many video file formats?
When choosing a file format, consider using a higher resolution to improve image quality, but be aware that this may increase file size and consume more computer resources during post-production. Therefore, it is recommended to select an appropriate resolution according to the requirements of the main playback platform and the end use.
The frame rate is an important factor for the smoothness of the video, the higher the frame rate, the smoother the video will be. However, the frame rate also affects the size of the movie, a 60p movie will be much larger than a 30p movie. In addition, in low-light environments, using a lower frame rate may result in better image quality.
Traffic refers to the download or streaming speed of a video, usually in Mbps. Selecting a higher data rate can increase the download speed of the video, but it will also increase the file size.
Compression coding is a compression technique used to store or transmit video. Choosing a different compression encoding method can control the file size, but it may also affect the quality of the image. For example, using a lower compression ratio can result in higher quality images, but the file size will also increase. Therefore, it is recommended to choose the appropriate compression encoding method according to the purpose and budget
Many people prefer to shoot video at 24p because it gives a film-like look with a high level of texture and aesthetics. However, the 30p and 60p pictures are more like TV shows or news, and may lack some "flavor". In Taiwan, the projection specification of TV is NTSC in the United States, while 60p and 30p are NTSC standards. Therefore, if incameraDon't be surprised to see 50p or 25p in the settings, because these settings belong to the PAL system of European regulations. Remember to switch to NTSC in the menu.
Videos can be in different file formats such as Sony's XVAC S, AVCHD, MP4, etc. Each archive format has its own specific flow and compression encodings. Traffic refers to the amount of recorded data, and the unit is Mbps. The higher the flow rate, the richer the quality and details of the image, but the larger the file size. For example, the XVAC S format supported by Sony α7S provides Full HD video at 50Mbps. The compression encoding method is an algorithm used to balance the file size and video quality. For example, Canon's EOS models provide IPB and All-I two compression formats after using DIGIC 5+. The former uses the "inter-frame algorithm" to provide a higher compression rate and a smaller file size, so it is suitable for long-term recording or instant uploading. The latter uses the "intra-frame algorithm" and gives priority to image quality, which is suitable for professional needs such as film and commercial shooting. Due to the low compression rate, it will be smoother when playing back on the computer or post-production editing.
Do I have to use a style file?
Applying a style file (adjustment file) is a technology used when shooting or recording images. Its purpose is to allow users to easily make images show different effects without complicated post-production. Professional videographers usually do color correction in post-production, so the purpose of applying a style file is usually to preserve the details of the image, to ensure that the highlights and shadows will not be overexposed or too dark, and the color will not be blown out and cannot be adjusted. E.g,Sony Provides S-Log2 and S-Log3 Gamma curves, Canon has CineStyle, and Nikon's new Flat after D810 is also a similar concept. Although their principles are slightly different, their purposes are roughly the same. With these profiles, the image will be gray and "flat" and the colors will be washed out, because their main purpose is to preserve the maximum dynamic range for post-production.
Aperture, Shutter and ISOhow to adjust
The shutter setting is the factor that affects the exposure time of the image. If you are shooting a still scene, you can use a shorter shutter time to achieve a lower ISO sensitivity to avoid noise. If you are shooting a moving scene, you can use Use a longer shutter time to reduce shake, but be aware that using a longer shutter time will blur the image, so use it in the right balance.
The last is the sensitivity, which is the ISO sensitivity. Its setting will affect the sharpness and noise of the image. The higher the sensitivity, the sharper the image will be, but it will also increase the generation of noise. Therefore, when shooting still scenes When shooting, you can use a lower ISO sensitivity to achieve better image quality, but if you are shooting a moving scene, you may need to use a higher ISO sensitivity to reduce shake, but be careful, use a higher ISO sensitivity Makes the image blurry and noisy, so use it in the right balance.
Sensitivity is to control the camera's sensitivity to light when recording or shooting, usually expressed in ISO value. The higher the sensitivity, the higher the sensitivity to light, and the camera can capture clearer images in darker environments, but at the same time it will increase background noise and reduce image quality. In video recording, the choice of sensitivity is also limited by the shutter speed. For example, when shooting static objects, you can use a higher sensitivity to reduce background noise; but when shooting dynamic images, due to the lower shutter speed, The sensitivity should not be too high, otherwise it will cause blurred effect. Therefore, when shooting dynamic images, it may be necessary to use a lower sensitivity, or set the sensitivity to a lower level, in order to maintain the clarity of the image.
Sensitivity refers to the sensitivity of a photosensitive element (such as a CCD or CMOS photoreceptor) to light. The higher the sensitivity, the higher the sensitivity means that the photosensitive element can capture enough light even under lower light, that is, it can work in a darker environment. Take a better photo or video in . However, it should be noted that the higher the sensitivity, the more noise there will be, especially in low-light environments. Therefore, when selecting the sensitivity, you need to take into account the current light conditions and the required image quality, and be aware that different camera systems may have different sensitivity setting methods.
Auto Focus VS Manual Focus
Autofocus can bring us great convenience when recording video, but it has a certain logic, and it will give priority to focusing on bright places or subjects closest to the lens. This means that we cannot control the focus position very precisely, let alone in low light conditions or when we want to convey image information through focus movement. Therefore, we recommend using manual focus. Manual focus does not require any special skills, the most important thing is experience and practice. However, we can use some auxiliary functions to make it easier, such as "focus peaking". The Log Gamma curve of some cameras makes the contrast of the picture very low. At this time, it is very difficult to focus even by zooming in on the image. In this case, the "focus peaking" function is very useful and can save us a lot of effort.
Automatic White Balance VS Manual White Balance
White balance is also a very important setting in photography. It can ensure that the color temperature of each picture is consistent, and it will be much easier in post-production. It is recommended to use manual white balance to ensure the correct color tone of the picture. In addition to adjusting the K value to change the color temperature, usually a pure white object (such as white paper, white wall or white clothes) is used to customize the white balance. However, there is no standard answer to whether the white balance is accurate or not. Whether the light is warmer or colder ultimately depends on the image atmosphere you want to convey. Therefore, the choice of white balance depends on the photographer's preference and creativity.
