Why do the photos taken by Nikon D200 and D80 with preset white balance always feel gray?

Generally speaking, there are the following factors that cause photos to be "gray":

1. Use low-grade digital cameras or low-grade lenses for SLR digital cameras. According to the experimental data published by foreign professional websites, the imaging quality of almost all digital cameras (I don't call them ccD because there are seven kinds of photoreceptors used in digital cameras at present, so it is relatively accurate to call them "photoreceptors") is far lower than that of ordinary cameras with the same lens 135 (using imported high-quality film). Because the yield of the photoreceptor used in digital cameras is not high, especially the yield of high-end products is less than 80%, the cost and price of the whole machine are much higher than that of ordinary cameras. Therefore, it is natural to expect that the quality of digital Dc imaging below 30 thousand yuan can really rival that of traditional cameras of the same value.

2. The exposure is inaccurate. The photoreceptors on digital cameras are sensitive to light, and the exposure latitude is much lower than the traditional negative film. It is prone to underexposure or overexposure. When the exposure is insufficient, the photos will become dark. Therefore, the exposure of digital cymbals is best controlled within the half-scale error. At the same time, try to use more accurate methods such as multipoint matrix photometry and spot photometry, and make accurate conversion, otherwise the exposure basis is inaccurate, and the camera will restore the main scene to medium gray according to the principle of 18% gray board.

3. Use the flash of the digital camera to expose in the dark. Most flash lamps of low-end digital machines have small indices. When used in a dark environment, the background will be seriously underexposed, which will make the photoreceptor produce noise and form fog.

4. The sensitivity setting is too high. When the light permits, it is recommended to adjust the sensitivity to the lowest value allowed by the camera to ensure sufficient contrast and delicate effect. This is like low-sensitivity film, which is much better than high-speed film in contrast, graininess and latitude.

5. The surface of the photoreceptor is dirty. SLR digital Dc is easy to be polluted by dust when changing lenses. Because the higher the resolution of the photoreceptor, the smaller the area of the photoreceptor, so a small amount of dust visible to the naked eye can obviously affect it, just like adding a layer of fog mirror, which will inevitably lead to a serious decline in imaging quality. At present, Nikon and other companies have begun to produce special cleaning tools for photoreceptors (see the news channel of Oriental Art Network for details). What needs to be emphasized here is that don't use ordinary lens cleaning tools such as lens paper, suede and alcohol to clean the photoreceptor, otherwise it will not only scratch its surface, but also get dirtier and dirtier.

6. The image resolution setting is low. In view of the congenital deficiency of low-grade digital cameras, it is suggested to choose the highest resolution as far as possible, and not to give up the relatively high-quality imaging quality in order to save memory card space. Because the imaging quality is very important to photographers. Of course, if the memory card is not enough when going out, or just to take some commemorative photos, it is not bad to reduce the imaging resolution appropriately.

7. The low-end high-magnification zoom digital camera adopts telephoto shooting. When a telephoto lens is used for long-distance shooting, the image fog is larger than that of a short-focus lens because of the shielding and scattering effects of dust in the air on light. Secondly, the proportion of cinematographers using low-grade digital cameras is relatively large. The optical structure of the photographic lens of this kind of low-grade high-power zoom digital camera is simple, the aberration correction is not strict, and the telephoto end is more obvious. Because of the cost, the relative aperture of this kind of lens is small at the telephoto end. Sometimes, in order to make the exposure accurate, we have to artificially improve the sensitivity as compensation to further increase the dry spots and fog.