Application of ND medium gray density mirror and GND gradient mirror in landscape photography

Lead: There are two kinds of filters that are essential in landscape photography, that is, medium gray scale mirror and gradient mirror. Let me talk about their use skills.

A, medium gray density mirror:

Neutral gray-scale mirror is also called neutral gray-scale mirror, or ND for short, and its function is to filter light.

The main purpose of using neodymium mirror is to prevent overexposure. If the light is too bright, it is difficult to choose a slower shutter speed. At this time, the ND mirror is used to reduce the light entering the lens, and a slower shutter can be used to shoot.

Actually, we don't need to write down these brand numbers. Many friends asked me whether to use ND8 or ND400. In fact, the brands we use may be different, and the number of downshifts of each brand is different.

Under the same lighting conditions, aperture size and ISO, the larger the number after nd, the higher the gear position.

Due to process reasons, the greater the coefficient behind nd, the more color cast. When we buy ND, we just need to say? What level of dimming ND mirror do I want to buy? ? Do it. If you often shoot water features in the afternoon, I suggest you buy a high-end nd. Now I have two ND configurations, one is Li's minus 3 gears, and the other is Li's big minus 10 gears. These two reducers are enough to meet most of my shooting needs.

Second, the basic principle of using nd

For example, when shooting at the seaside, the aperture is set to 1 1 and the ISO is set to 100. We use spotlight to measure the bright area in the sky. After measurement, the shutter is 1 000 part of1second, and we get a set of data to take this photo: F 1 1.

If we want to shoot the atomized water surface, or if the shutter of 1000/ 1 sec is as calm as a mirror, it is definitely not possible. At this time, it is necessary to install nd in front of the lens to reduce the amount of light entering. Because it's afternoon, the sun is strong, and the shutter speed reaches 1000/ s, so we use 10 step nd to adjust the light. Is to reduce the shutter speed of 10, and each speed is to reduce the shutter speed by half. Let's calculate the shutter speed after subtracting 10 from 1000 in the next second:

1000/ 1 sec? 2=500/ 1 sec

500/ 1 sec? 2=250/ 1 sec

250/ 1 sec? 2= 125/ 1 sec

125/ 1 sec? 2=60/ 1 sec

60/ 1 sec? 2=30/ 1 sec

30/ 1 sec? 2= 16/ 1 sec

16/ 1 sec? 2=8/ 1 sec

8/ 1 sec? 2=4/ 1 sec

4/ 1 sec? 2=2/ 1 sec

2/ 1 sec? 2= 1 sec

Count it, is it ten times? That is to say, after we got this ten-level ND, our shutter has been continuously lowered by ten levels. Of course, if we also use CPL (Polarizer) superimposed, we can continue to extend the shutter by two steps under the condition of 1 sec: 1 sec? 2=2 seconds, 2 seconds? 2=4 seconds

If we superimpose a two-step GND (gradient mirror) in front, the shutter speed will continue to be extended by two steps: 4 seconds? 2=8 seconds, 8 seconds? 2= 16 second

The above data analysis can intuitively express the use and calculation method of nd.

If the exposure time of 16 seconds can't achieve the ideal atomization effect (sometimes it is necessary to atomize the sea surface, and a big wave will be formed after hitting the rocks for more than 30 seconds), we can also extend the exposure time by other means, such as lowering the aperture by one level, or adjusting the ISO to 50, or even overexposing the photos by one level (for the photos in RAW format that have been overexposed by one level, they can be pulled back at will later).

Third, adopt the correct exposure method.

When shooting in RAW format, it is recommended to use? Right exposure mode (histogram)? That is to say, it is better to expose than to owe. In digital photography, 80% of the information contained in a photo is concentrated in the bright part, which means that if the photo is underexposed, many details in the photo will be lost. Try to brighten the dark parts of underexposed photos later, and you will find a lot of noise. These noises are caused by underexposed pixels, so the software can only replace these pixels with noises.

This photo uses the 10 file of ND. Long exposure makes the clouds in the sky look like a drawing that is usually invisible to the naked eye, which is very shocking to the eyes. Later, some color adjustments were made to make the whole photo feel the end of the world. Shooting such a cloud effect must be done on a windy day with clouds.

Digital photography can allow overexposure of 1-2 files. On the other hand, I tend to be slightly overexposed when the highlights don't overflow, so that the RAW file in the camera can record more information in the photo, and LR can pull back the overexposed part at will to ensure that the information recorded in the whole photo is intact. Of course, this theory only applies to Canon cameras, but Nikon cameras are just the opposite, so it is better not to expose them. Those with Nikon cameras can try it and see which concept is correct.

In this photo, the third gear ND is used to streamline the high-speed traffic on the bridge.

In addition, the exposure time using ND is not as long as possible. Sometimes a few seconds of exposure also has its unique charm. The long exposure time should not exceed 200 seconds, and ISO should try to ensure that it is 100, otherwise any noise reduction plug-in can't eliminate the noise in the photo.

4. What if there is no ND medium gray density mirror?

Without ND, in order to increase the exposure time, the ISO can be reduced to 50 and the aperture set to 22, which can maximize the exposure time. This photo was not taken with a filter.

Five, GND gradient mirror: square plug-in gradient, gradient mirror is divided into hard edge and soft edge.

Hard edge transition: the transition between bright and dark parts is sharp. Under normal circumstances, it is used when shooting waterscape, seascape and sharp vision;

Excessive soft edges: generally suitable for shooting the transition of mountains is not very sharp.

When there is a light ratio between the sky and the ground (or water surface), the gradient mirror GND is used. Without using GND, we often take a pale photo with normal ground exposure, overexposed sky and no details, or the sky is normally exposed, but the ground exposure is insufficient, so we can't find a exposure value with the best of both worlds. This is because GND, which is necessary in landscape photography, is not used. In our daily shooting process, the sky is usually brighter than the ground, so in order to ensure the consistency of exposure from top to bottom, we need a gradient mirror to suppress the light above. The upper part of GND is a medium gray area, and the lower part is a transparent area.

GND is generally divided into:

0.3 first gear,

0.6 two gears,

0.9 third gear,

1.2 fourth gear,

1.5 5th gear

The highest utilization rate is the second and third gears.

Six, the use of GND gradient mirror

Use of GND gradient mirror

For example, when taking a sea view, set the camera to F 1 1, ISO 100. First, measure the bright areas in the sky with a spotlight, and the shutter is 1 sec. Then use a spotlight to measure the dark areas in the water, and the shutter is 1 sec. Then we can get up and down. Through calculation, two steps GND should be used to take this photo to balance the upper and lower light ratios.

This photo is the most typical example of using GND.

This photo is the most typical example of using GND, and it was taken against the light. The light in the sky is very strong. If you don't use GND to make this movie, either the ground is dead black or the sky is dead white. After photometry, there are five light ratios. I used two GND stacks to suppress the strong light in the sky.