What is a medium grey mirror? What brand of medium grey mirror should I buy?

A good medium gray mirror simply reduces the brightness, hardly changes the original color of the picture, and does not reduce the sharpness too much, while a mirror near medium gray not only changes the color, but also reduces the sharpness. For landscape photography, it is recommended to buy a better filter as much as possible.

Next, let's take a look at grey mirror's explanation in landscape photography.

What is a gray mirror?

Medium gray mirror is a kind of camera lens with filter, and its appearance is no different from that of ordinary UV mirror, which plays a role in weakening the light entering the lens. The medium gray mirror has no effect on color and does not change the light contrast of the subject, so it is also called neutral gray light-blocking film (on average, it only weakens the light intensity). It is mainly used to reduce excessive light. It can be clearly seen from the proofs that even during the day, the slow shutter effect that only exists at night can be taken.

A good medium gray mirror simply reduces the brightness, hardly changes the original color of the picture, and does not reduce the sharpness too much, while a mirror near medium gray not only changes the color, but also reduces the sharpness. For landscape photography, it is recommended to buy a better filter as much as possible.

Because it has the function of reducing the amount of light entering, reducing the aperture or minimizing ISO can also reduce the shutter speed. Why do you need a gray mirror? Because the light is generally strong during the day, that is to say, if the aperture is set to the minimum and ISO is set to a lower level, the shutter speed cannot reach a slower value. In addition, the aperture setting is too small, which is easy to cause diffraction. Simply put, the image quality will be reduced. Therefore, landscape photographers would rather buy a medium gray mirror than take pictures with a small aperture. That's the reason.

How to calculate the dimming amount?

There will be some English and digital signs around the box or mirror ring of the medium gray mirror. Let's start with HOYA, a UV mirror.

The outer packaging of UV mirror is similar. Except for the different patterns between brands, the biggest difference is that there will be an obvious ND sign on the front of the package, followed by a number (ND4 in the above picture), which means reducing the shutter speed of two gears. So how to calculate the dimming amount of the medium gray mirror? It's simple. The number on the middle gray mirror is a power of 2, which means that the shutter speed is reduced by several levels. For example, ND8,8 is a power of 3, so nd8 means that the shutter speed is reduced by 3 levels. In order to meet different shooting needs, the ND mirror is divided into many gears, ranging from ND2 and ND4 to ND 10000.

Which is better, a square grey mirror or a round grey mirror?

There are two kinds of gray-scale mirrors in appearance: one is a square gray-scale mirror, which needs to buy a filter bracket separately to be stuck at the front end of the lens, and the other is a round gray-scale mirror, which can be screwed directly at the front end of the lens through threads.

The advantage of a square medium-sized grey mirror is that you don't have to worry about the different aperture of the lens. Grey mirror in 1 can be used with any lens, but the disadvantage is that such a large medium-sized grey mirror is very inconvenient to carry. Because it can't be equipped with a hood, the imaging effect under backlight will be greatly reduced. Circular polarizers do not have the above problems. The only trouble is that if the lenses have different calibers, if you have many lenses, you may buy several sets of medium gray lenses with different calibers, but generally speaking, buying round medium gray lenses is the vast majority of choices.

What is a variable grey mirror?

Seeing this, some careful netizens may find that if you only buy a fixed medium gray mirror, you will definitely not be able to adapt to the environment in different light, but if you buy a combination of multiple medium gray mirrors, the price will be very high. Is there any other way?

If you are a local tyrant, buy all the commonly used gray lenses, so you don't have to worry about not being worthy of gray lenses. However, if you don't pursue image quality, you can try to buy a variable ND mirror, such as ND2-ND400, which looks like a polarizer. After installing the front end of the lens, the gray scale can be changed by rotating the middle gray mirror.

The biggest problem of this kind of medium gray mirror is poor image quality and easy color cast. In addition, when the equivalent focal length is less than 28mm, there will be cross-interference, even for the expensive variable grey mirror. When taking landscape photos, the focal length is usually less than 28mm, so it is recommended not to buy the variable grey mirror.

What brand of medium gray mirror should I buy?

It's normal for grey mirror to sell a few dollars for better accessories, but domestic brands have advised against buying them, even if they are cheap, it's impossible to use them. Wasting money is a trivial matter. If you are going to travel to a scenic spot that you have been exploring for half a month, and it turns out that the color cast seriously affects the image quality, what is your mood? Novices can buy NISI and HOYA, and B+W and Haitai can be considered if the budget is sufficient.