What's the shot of the dog's head?

Generally refers to the cheap entry-level low-end lens. This kind of lens is not clear, and the distortion and dispersion are not handled very well. In the primary stage of optical products, some popular lenses are seriously distorted, and some exaggerated claims are that people can be photographed as dog heads. But up to now, as long as it is not a famous factory and a mirror, it has been called a dog's head by nitpicking people. Even a dog's head is a hundred times better than a DC lens.

Dog head lens refers to Nikon's G-type bayonet series lens. In recent years, Nikon has introduced G series lenses without aperture ring, and takes G series as the development direction of Nikon's future lenses. Because of this move by Nikon, this series of lenses can't be used on well-known cameras such as Nikon manual cameras, F90 series cameras and F4 cameras, which has caused dissatisfaction among many Nikon fans.

In addition, Nikon's G series lenses first appeared in the form of two low-end small aperture and low-cost consumer-grade lenses, and G is also the initials of "gou". Northerners love to use "dogs" to describe anything. For the above reasons, the "dog head" spread.

In film and television, the lens has two fingers, one refers to the optical components used by film cameras and projectors to produce images, the other refers to the continuous picture taken from power on to power off, or the fragment between two editing points, also known as the lens.

One finger and two fingers are two completely different concepts. In order to distinguish, one refers to the optical lens and the other refers to the lens picture. According to the origin of lenses, mainly Japanese lenses and German lenses. Japanese lenses mainly have good color reproduction, while German lenses have a strong sense of layering. China's lens has gradually occupied a certain market in the market, mainly because the price is relatively low.

According to the performance and appearance of lenses, there are currently P-type, E-type, L-type and auto-zoom lenses. The information from China Instrument Supermarket is described as follows:

1.p lens

(1) Automatically position the lens, and the pupil focus has been adjusted. It is necessary to check whether the definition from the maximum magnification to the minimum magnification is consistent and clear.

(2) Check the coaxiality, that is, the images from the maximum magnification to the minimum magnification are taken at the same position, and cannot be offset or offset too much, which is regarded as defective, and the lens must be replaced again.

(3) The optical magnification is 0.7-4.5X, that is, nine magnifications ranging from 0.7 to 4.5 times.

(4) Judging the clarity according to the imaging reflection of the correction block and the actual object.

2.e lens

(1) This lens is an ordinary industrial lens, and the pupil focal length needs to be adjusted manually. After the machine is installed, when the maximum magnification and the minimum magnification are manually adjusted, the image is equally clear. Those whose sharpness cannot be adjusted are regarded as defective products, and those with unstable factors such as jitter after adjustment are also regarded as defective products.

(2) Check the coaxiality, that is, the images from the maximum magnification to the minimum magnification are taken at the same position, and cannot be offset or offset too much, which is regarded as defective, and the lens must be replaced again.

(3) The optical magnification is 0.7-4.5 times.

(4) Explain the definition according to the imaging reflection of the calibration block and the actual object.

3.l lens

(1) This lens is an ordinary industrial lens, and the pupil focal length needs to be adjusted manually. After the machine is installed, manually adjust the maximum magnification and minimum magnification, and the image is also clear. Those whose sharpness cannot be adjusted are regarded as defective products, and those with unstable factors such as jitter after adjustment are also regarded as defective products.

(2) Check the coaxiality, that is, the images from the maximum magnification to the minimum magnification are taken at the same position, and cannot be offset or offset too much, which is regarded as defective, and the lens must be replaced again.

(3) The optical magnification is 0.7-4.5 times.

(4) Explain the definition according to the imaging reflection of the calibration block and the actual object.

4. Automatic zoom lens

(1) Automatic positioning, the pupil focus of the lens itself has been adjusted, and it is necessary to check whether the definition from the maximum magnification to the minimum magnification is consistent and clear.

(2) Check the coaxiality, that is, the images from the maximum magnification to the minimum magnification are taken at the same position, and cannot be offset or offset too much, which is regarded as defective, and the lens must be replaced again.

(3) The optical magnification is 0.7-4.5 times.

(4) Explain the definition according to the imaging reflection of the calibration block and the actual object.