The secret of the magical use of black cards in landscape photography

When it comes to black cards, we should start with the gradient mirror. Gradient mirror is used to balance the light ratio of up and down or left and right, half deep and half shallow, and is mostly used to darken the sky and reduce the light difference between the upper and lower parts. However, the balance coefficient of gradient mirror is limited, generally the maximum is 3 levels. If the light difference between the upper and lower parts exceeds 3 levels, the gradient mirror can do nothing. Of course, it can also be used by superimposing two layers of gradient mirrors.

However, as the saying goes, more lenses, more ghosts, one UV. Even with multi-layer coating, the differences between brands are obvious, not to mention the gradient lenses made of most resins.

Gradient mirror

At this time, the black card is useful. Black card, as the name implies, is a black card, which is opaque and reflective, and the material is not limited.

Simply use the black card: The reason is simple, that is, use the black card instead of the gradient mirror to cover the parts that need to be covered. Different from the gradient mirror, the gradient mirror is fixed in front of the camera, while the black card needs to shake up and down artificially to create the gradient effect, and the size of the shaking can determine the boundary trace of the gradient part. Generally, the amplitude does not need to be too large, and it can be shaken rhythmically.

Just like using a gradient lens, when using a black card, photometry needs to measure the upper and lower parts separately, and then calculate the difference between the upper and lower light, that is, the upper exposure time and the lower exposure time. The time to cover the upper part with a black card is the exposure time of the lower part minus the exposure time of the upper part. For example, after photometric calculation, the sky part is 1 sec and the ground part is1sec, so that the black card is blocked for 9 seconds and the ground is exposed for1sec.

This is a relatively simple black card application, which is more complicated. You can also divide the picture into three parts: upper, middle and lower. Cover the black card on the middle and upper part, and let the lower part be exposed. Then move the black card to the upper and middle boundaries, so that the lower and middle parts are exposed and continue to cover the upper part. Finally, it is more complicated to remove the black card and expose the upper part.

In other words, the black card can also be used obliquely in terrain environments such as sloping hillsides. Simply put, the picture is divided into two or three parts in advance and exposed separately.

In most cases, the black card effect can be synthesized at the end of the second and third stages. Only in very special cases, it is difficult to synthesize in the later stage. For example, the scene below is facing the sun, because the lens will produce glare. In addition, the sunlight covers the foreground, and the resulting image is exposed and overflowed, so it is difficult to take a clean foreground.

Some points for attention in using black cards:

Be sure to use a tripod.

Be sure to use cable release (or remote control, or delayed exposure).

Press and hold the preview of depth of field to determine where to place the black card.

Shake it, control the rhythm and press the shutter (it's too late to press the shutter).