What is a black card?

The shaking black card is a small black card. The material can be a slightly hard material, such as cardboard, plastic, etc. , but the surface needs matte, matte and hair transplant. The purpose is to reduce reflection and refraction.

Shake the black card, and then cover the brighter part of the image with black non-reflective paper to give the darker part more shooting time.

A black card is simply to cover the brighter part of the image with black non-reflective paper, so that the darker part can be inserted into the inserted shooting time. When using a black card, you should shake it slightly to avoid leaving a black card, so the black card technology is called a black card.

Extended data:

Dimmer can bring more exposure to your creation, make the sky darker and create space for your creation. In many cases, due to the intensity of external light, we cannot get enough shutter time. Take my own photography principle as an example. For example, shooting in the wild, we want to use the shutter for one second to make the water as soft as cotton.

Due to the strong light, the camera has the smallest aperture and the smallest ISO shooting, and the shutter speed is still about 1/30 seconds. The only way is to use one or even two ND8 lenses to attenuate the light entering the lens.

There is a simple formula, assuming that your camera has no dimmer and the normal exposure shutter speed is t, and then under the same lighting conditions, aperture size and ISO, after adding a dimmer, the normal exposure shutter speed = t * x；;

X is the number marked after the dimming lens, x = 4 for ND4 and x = 8 for ND8. Due to this process, the greater the coefficient after ND, the greater the color temperature.

Household dimmer has a great influence on color temperature, but it is cheap and suitable for amateur photographers. The influence of imported high-end dimmer on color temperature is almost negligible, so it is a cost-effective choice.

The filtering effect of the dimmer is non-selective, and the attenuation ability of light with various wavelengths is equal and uniform. In this way, the dimmer will not have any influence on the color of the original object, and the scene can be accurately reproduced. Contrast (due to this process, the color temperature will still have a small deviation).

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