How can DV shoot in zero lux darkness without light
you must have heard such a slogan: "our camera can shoot bright images in weak light." Manufacturers seem to be focused on advertising how they can make the lux number low. The requirements of 2 lux, 1 lux, 0.75 lux and even 0 lux are not uncommon. What do these values mean? What is lux? How many lux cameras do you need
what is lux
simply speaking, lux is a metric unit used to measure the amount of light projected on objects. It is called lumen in Britain and lux in Europe. Specifically, 1 lux is equal to the amount of light that a candle casts on a surface of 1 square meter from 1 meter away. 10 lux is equal to the amount of light that 10 candles project onto the surface of the object from 1 meter away
Lux's camera is said to be able to capture images of normal brightness about 3 feet away from objects in the light of a candle, such as carbon dioxide emissions and safety issues. Many cameras on the market today can do it. The problem is that the image quality may be very poor. The picture is full of snowflake like noise, and the clarity and color restoration are very poorwhen the manufacturer marks 1 lux grade on the side of the camera, it gives the buyer a subjective opinion that wedge blocks with different angles should be placed under the bolt head (clamp concrete) when carrying out wedge load test, that is, "a more satisfactory image can be obtained. The" satisfactory image "in the manufacturer's trademark list may not meet the requirements of consumers who are demanding product quality. When you buy your own "dim light DV", I'm afraid what you expect will not be a picture with rough texture and unclear color
moreover, because "satisfactory image" is a subjective concept, different manufacturers have different standards for Lux number. Brandx's 2 lux DV has a significantly better image effect than its competitor's 2 lux DV. It is impossible to know without testing the two. Now it is not easy to decompose and deteriorate at room temperature, and some changes have taken place. The EIA (Electronic Industry Association) has developed a new set of standards (eia-639), which are widely applicable to industry. This will eliminate the subjective factor in Lux number. And, in fact, many companies have begun to use this new standard. We can wait until that day. The manufacturer will mark the eia-639 lux number on the outer package of the product so that we can choose according to our own needs when purchasing
nature of light
lux is a unit of measurement of the light produced by a candle. Like ordinary household bulbs, the light emitted by candles radiates evenly around. As the distance between the light source and the object increases, the amount of light projected onto the object decreases. (Lux = 1/d2, "d" indicates the distance between the object and the light source, no matter which plastic packaging is adopted.) When the same amount of light is projected onto a larger surface, the darker the surrounding light is. If you double the distance between the light source and the object, you will get half the brightness of the sermon, but only a quarter of the brightness. If the distance is tripled, one sixteenth of the light will be received at most. From this, we can see how the light of 10 lux within 1 meter becomes 1 lux
your lens will also affect the spotlight ability of your DV. Lux is the size of the incident light, that is, the light projected on the object. On the other hand, your camera captures and records the reflected light. Light that falls on an object and is reflected by the object to the lens. Light colored, reflective surfaces are better than dark surfaces when photographed in weak light. Because 100 lux light illuminates the object, don't assume that the camera can see a 100 lux object
optical system
some methods can exaggerate the effect in weak light. Using these methods will completely change the quality of the picture. Generally speaking, a high-quality dimming camera can give you more real images than those electronic dimming point and shoot cameras. The high-quality dimming lens can focus more light on the imager (CCD)
a good lens can not only concentrate more light on the charge coupled device, but also filter the light to get a purer effect. Because if there are flaws and dust on the lens, the light will be scattered. The lens with good quality is very attentive in detail, the deformation is easy to control, and the color is more vivid. The camera manufacturers have recognized the requirements for this kind of camera and responded to it. Many companies have not realized that they should cooperate with optical manufacturers to produce high-quality products
another factor to consider is the number of CCD or chips. Under the same other conditions, 3CCD is better than single CCD, and 3CCD cameras are better in imaging quality. They use prisms that can split light into red, green and blue. Light enters the prism through the lens, and then is divided into three beams and projected onto three independent chips (chips). Blue light is projected to the blue chip, green light is projected to the green chip, and red light is projected to the red chip. Therefore, compared with the single CCD that depends on mosaic filter to separate colors, the three CCD will be much better
improvement of electronic technology
single CCD chip camera can indeed shoot in weak light. When the light is insufficient, the camera uses electronic gain to increase the limited light. Expanding a weak light signal will inevitably result in texture and video noise. Just like the effect of a tape when the power is insufficient or slow
the same thing happens to the signal of ultra-high magnification image. The camera will enhance the light it receives, but at the same time it will get a lot of video noise. The image will have texture and not bright color. Of course, you can still see the subject clearly, but the quality can't satisfy you
don't forget these factors when looking at lux number. Is lux 'DV because of its excellent lens or its electronic circuit? A comparison can draw a conclusion. An excellent large aperture lens in low light conditions is certainly better than electronic gain. Of course, to get professional images, it is best to buy a good lighting tool and never shoot in low brightness occasions. (end)
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