Liuhanfeng photography

The design and production of standard lenses are relatively easy. The lenses with aperture F 1.2 and F 1.4 are both 50mm standard lenses, which is almost the largest aperture value in photographic lenses. The standard lens with large aperture is often the lens with the best optical quality produced by this manufacturer. My early Nikon 50mmF 1.2 lens and 50mmF 1.4 lens, although useless for more than 20 years, are still treasured. F 1.2 is not bigger than F 1.4, but it is twice as expensive because the manufacturing process is much more complicated. The aperture of the lens is large, and the glass wool used needs to be large, so the man-hour of grinding the lens will increase. In addition, large aperture will also bring color difference and aberration. The solution is to add special lenses to make up for it, which will increase the cost. (The picture shows the picture taken by F 1.2 aperture.)

A large aperture means a large amount of light, which is very advantageous when shooting in low light, especially in the film age where sensitivity is difficult to improve (ISO800 is great). The sensitivity of modern digital cameras can be adjusted at will, reaching ISO6400 or even higher. In this case, the aperture advantage of about half a level will be the same as that of chicken ribs. A large aperture also means that the background can be blurred to highlight the subject. Numerically, the aperture of F 1.2 is more blurred than that of F 1.4, but there is not much visual difference in actual use. (The picture shows the photo taken by F 1.2 aperture. Photography: Liu Yufeng)

Some people say that if the aperture of 50mmF 1.2 lens is reduced to F 1.4, the photos taken are better than those taken by 50mmF 1.4 lens at F 1.4 aperture. I do agree with this view. The problem is that almost no one will do this in actual shooting. In order to pursue the large aperture effect, they will choose the maximum aperture value of F 1.2 without any scruples. (The picture shows the photo taken at F 1.4 aperture. Photography: Liu Yufeng)

Let's get straight to the point. First, let's talk about the price that everyone cares about most.

In order to make the contrast more obvious, taking Canon 50 fixed focus as an example, the biggest difference between 1.2 and 1.4 is the price. The JD.COM price of 1.2 is 9299 yuan, 1.4 is 2499 yuan, and 1.8 is 698 yuan. We can see the obvious difference from the price figures. So let's take a look at the imaging effect.

F 1.2 imaging effect

F 1.4 imaging effect

F 1.8 imaging effect

From an intuitive visual point of view, the gap between similar apertures is not very big, and the background blur effect is basically not too big, but if you directly compare 1.2 and 1.8, the gap is still obvious.

Then, we are looking at an official lens quality chart.

From left to right are the official lens data maps of f1.2f1.4f1.8, from which we can clearly see their differences. So it is understandable that there is such a big gap in prices.

In short, the larger the aperture, the higher the price and the more complicated the lens manufacturing process. Everyone is buying lenses. You can buy a big aperture if you have money. The bigger the better. If you have no money, you can buy a dog head to play with. As long as you work hard, you may be able to make a good movie.

The lens aperture number is actually reciprocal, and the strict writing is f/ 1.2 and f/ 1.4. Where f stands for focal length, what is the significance of this aperture number? It represents the aperture of the lens (let's assume its code name is D)

A simple example, such as Canon 50L, has a focal length of 50mm and a maximum aperture of f/ 1.2. Then the maximum aperture of this lens is d1= 50/1.2 = 41.667mm. When the aperture of this lens is reduced to f/ 1.4, D2 = 50/1.4 = 35. ..

We know from middle school that the area of a circle is s = π r 2.

Therefore, in the state of f/ 1.2, the light transmittance of the lens is 36 times that of f/ 1.4. That is to say, when the lens of f/ 1.4 uses ISO 6400, the lens of f/ 1.2 only needs ISO 5000 (the calculated value is greater than 4700) to shoot.

Because the aperture number can measure the light passing ability of the lens, it is traditionally called "large aperture lens" as "high-speed lens". (The high speed here refers to the light passing ability, not the focusing speed. )

How big is it? Let's start with the price:

F 1.2 is generally twice as expensive as F 1.4.

The weight of F 1.2 will be heavier than that of F 1.4.

F 1.2 is sharper than F 1.4 in sharpness.

It's really not on camera. It must be expensive. The aperture of F 1.2 is larger than that of F 1.4 in weak light. Sharpness can be better preserved.

As far as use is concerned, buy 1.2F if you can afford it, and generally F 1.4 if you can afford it, but people who buy F 1.2 aperture rarely use this size. All lenses have an optimal aperture and focal length (zoom), and the optimal aperture is often not the largest one, so they all shoot an aperture. You can use F 1.4 or F 1.8 at this time. But F 1.4 will also use a smaller aperture.

This is the size of the aperture value, or how different it is. Thank you for reading, like my answer, please take care of Zeng Xi 5, thank you!

Generally speaking, the aperture is distinguished by the aperture. Complete f values are F 1.0, F 1.4, F2, F2.8, F4, F5.6, F8, f1,F 16, F22, F32, F44. These are called full apertures. The luminous flux difference between adjacent full aperture is doubled. For example, F 1 is twice that of F 1.4, 1.4 is twice that of 2, and 2 is twice that of 2.8, so 1.4 is four times that of 2.8, and their luminous fluxes constitute a geometric series: 2 n power. For example, 1.4 and 2.8 have two full aperture differences, so the ratio of luminous flux is 2 to the second power, which is 4 times. Others can be inferred in the same way. F 1.2 and F 1.8 are called semi-apertures, and the luminous flux is 0.5 times different.

The standard equations of shutter are 1, 1/2, 1/4, 1/8,1/5, 1/30,1.

Therefore, under the same sensitivity (ISO), if you want to take photos with the same correct exposure, the shutter speed will increase by one step with a larger aperture, and vice versa. F 1.2 is more than half an aperture than F 1.4, and the shutter speed can be increased by half an aperture.

Generally speaking, the aperture of a camera lens is f,

F is the aperture value, which is a ratio and has no unit. Aperture value represents luminous flux. The larger the luminous flux, the smaller the aperture value. The smaller the luminous flux, the larger the aperture value. They are inversely proportional. Fixed focus lenses generally use a large aperture. The zoom lens of an ordinary camera can't exceed f2.8 because of its structure.

The biggest difference in aperture size is the depth of field. In the case of large aperture, due to the increase of aperture, the clear range of light converging on the focal plane is very short, which makes focusing very difficult. It is necessary to adjust the focusing ring very accurately to make the scene definition meet the requirements.

Simply put, large aperture has small depth of field and small aperture has large depth of field. Compared with the aperture values of f 1.2f and 1.4, the luminous flux difference is nearly twice, and the depth of field range of f 1.2 is more extreme, which is more difficult in optical design and imaging quality, and the manufacturing cost will also increase. The lens with the maximum aperture of f 1.4 can meet the needs of most scenes and will not be compared with f 1.2. The design and manufacture of the maximum f 1.4 aperture lens have been very mature, and the price has become civilian.

In fact, f 1.2 aperture lens is a niche product made by lens manufacturers to show their technical level. The ultimate goal pursued by the Equipment Party is not what most photographers need.

The difference is mainly reflected in

1 backlight shooting

When shooting in low light.

3 focusing speed

I hope it helps you. If you have any questions, please talk to me in private.

As far as Canon's 50mm focal length fixed-focus lens is concerned, 50/ 1.2 belongs to the top high-end lens, and 50/ 1.4 belongs to the mid-range lens. The maximum aperture of this kind of large aperture lens often has problems such as dispersion and poor imaging quality, so it is generally necessary to reduce the aperture by one step.

1. Generally, the larger the aperture, the smaller the number. F 1.4 is less than F 1.2.

2.f The aperture value we are talking about is a numerical value, and there is no unit.

3.f, also known as focal length, is called mm mm, and the standard focal length of 135 full-frame camera is 50 mm ..

The most important thing is the price. For the same focal length, take 50F 1.4 and 50F 1.2, the price of F 1.2 is more than twice as expensive as that of 1.4, and the same size will be much larger.

5. See what kind of lens you need and what kind of lens to match. The most important thing is the artistic conception of your composition.

First, the price. For the same focal length, take 50F 1.4 and 50F 1.2, the price of F 1.2 is more than twice as expensive as that of 1.4, and the same size will be much larger. Because the optical structure used after adding the aperture is more complicated. In this case, the natural price will rise a lot and the cost will be high.

One aperture and one shutter, under the premise of the same aperture, the amount of light can be increased or decreased by adding or subtracting shutters. Similarly, under the condition that the shutter is constant, adding or subtracting the aperture can increase or decrease the light input, so the larger the aperture, the greater the light input. Similarly, you can blur better and get a shallower depth of field.

Similarly, the differences in image quality, such as F 1.4 and F 1.2, the same lens, sharpness and image quality, F 1.4 lens in the aperture of 1.4, F 1.2 lens aperture reduced to F/kloc. This is another aspect that the lens quality of F 1.2 is better than that of F 1.4, and when you are in a low light environment, the extra aperture can better ensure the shutter and increase your shooting convenience, which is also the advantage of a large aperture lens.