Why can t a point and shoot camera display exactly the same image as it was recorded on film?

Because the framing principle of point-and-shoot cameras is mostly side-axis framing.

That is, the optical axis of the imaging and the optical axis of the framing are not the same optical axis.

Therefore, the picture seen in the framing and the actual image must be incorrect.

High-end rangefinder cameras correct for this error during the production process.

As for the DSLR camera you mentioned.

The imaging and framing of the DSLR are coaxial.

Framing is achieved by splitting the light entering the lens through a reflector and a pentaprism.

Therefore, the framing of the SLR is much more precise.

But there are inevitably errors.

This is marked again when buying a high-end camera.

It is mainly not a single-reflex structure, and it is generally paraaxial.

The SLR structure is to reflect the scene in the lens to the viewfinder through the reflector, and what you see is what you get, and when shooting, the reflector is retracted and the shutter works at the same time. However, if the viewfinder of the DSLR is not 100%, the actual object you see will be a little smaller than the original.

The rangefinder is not framed through the lens, but another way of framing, generally the viewfinder that everyone sees, the front and back are illuminated, and you can also zoom according to the lens, simulating the distance and proximity, remember that the scene you see at this time is the size of the simulation, and you can see it without opening the lens. When shooting, you can work directly with the shutter, and sometimes you forget to remove the lens cap, and there are more cases of shooting. Because the viewfinder is positioned higher than the actual lens, and it is an analog lens zoom adjustment, it is normal to have a difference.

No single camera can fully reproduce the real picture.

DSLR cameras.

It is named because of the structural features, it has a reflector and a pentaprism and a mount, which are not available in these ordinary cameras The lens of the SLR camera is divided into high, medium and low grades, which are suitable for different shooting purposes, and are divided into four categories according to the focal length: fisheye, short focus, standard, and telephoto. Let's talk about imaging features 1There is a serious distortion aberration in the fisheye, the distortion is the largest, and the illumination of the image field is relatively uniform.

2.The distortion of the short-throw image is corrected, and the distortion aberration is reduced. The illumination at the edge of the image field is low.

3.Standard, focal length, medium angle of view, perspective relationship is similar to human vision, and realistic reproducibility is strong. 4.

The telephoto angle of view is narrow, and the spatial visual effect is weak.

According to the structure, it is necessary to fix the focus, zoom, revert, shift the tilt, etc.

3.The volume of the card machine is the primary condition, if you want to do 18 times the zoom is not the specialty of the card machine, the two can not be compared with each other, the image quality comparison is generally better than the telephoto all-in-one machine, because the lens volume and caliber are larger

1.The structure of the SLR machine is different, and the image quality is much better than that of the large-format sensor and large-aperture lens of the common machine.

Professional manual function.

2.The lens process is very demanding, and it is required to faithfully restore color and image There are wide-angle lenses from focal length and field of view, standard lenses, medium focal length lenses, telephoto lenses, and wide-angle lenses are mostly used to shoot landscapes and large-scale scenes, and standard lenses are used for various purposes Medium focal lenses are commonly used portrait lenses Telephoto lenses are used to shoot distant objects.

The focal length of the zoom lens is variable and can replace several prime lenses, but the image quality is not as good as that of the prime focal head 3Senior photographers rarely use large-magnification zoom lenses, because of the optical quality problems, cheap telephoto models must not work, birth defects.

Expensive telephoto machines are very cost-effective Low quality** Not as good as ordinary models of the grade, buy a popular camera, the lens zoom factor should be within 5.

Downstairs is copy-pasting.

Downstairs is copy-pasting.

Downstairs is copy-pasting.

The third question with reference to laptops is that the 12-inch with the same configuration is three times more expensive than the 15-inch.

In my opinion, the camera.

It is divided into full-frame cameras, APS format cameras, both of which are SLR cameras, and the third type is called consumer cameras, including various quasi-cameras"Professional machine"For example, the Canon G10 Panasonic LX3 is available, as well as telephoto and card players. The main difference between DSLR cameras and consumer cameras is the size of the CCD. The lenses of SLR cameras are not all expensive, professional ones are expensive, and some sleeves are also very cheap!

Why are professional lenses expensive? You get what you pay for, the ordinary ones are resin aspherical, and the professional ones are aspheric glass grinding, and the fluorite glass is used for telephoto, and then it may be that there are more profits, hehe, who said that China can't produce these things. I think why the image of the card machine is poor, not to mention anything else, you look at the lens, it's just the size of a new dime in diameter!

In previous years, the diameter of the camera was 37mm, which was small, and then look at the current one, the optical viewfinder was canceled, and it was said to be 37mm, and a quadrangular frame was added to the lens, and the lens inside was not much bigger than a dime! The above is a personal opinion only.

The so-called SLR.

The camera, which refers to a single-lens reflex camera. bai

It is different from the card machine in that it generally plays with the lens of the SLR camera, and the DAO can manually adjust the white balance, focus, and aperture. This can be used when shooting certain art**, which is certainly not possible with a card camera, and a DSLR camera reflects more than just its professionalism. And its performance.

As for the lens, it is expensive because of the image sensor and lens inside. Of course, the more lenses, the more expensive they are, such as CMOS CCD and other image sensors, it is expensive in these places, which is a combination of technology and technology. So you have to understand some camera common sense.

Understand some principles of optics. Tens of millions of pixels are a very common thing, and the lens is divided into fixed focus, telephoto, and medium focus. Playing prime is the most awesome, but also the least fun one, the zoom lens is very suitable for novices to play, such as buying a Nikon D90 you with a lens 18mm-200mm a lens to go to the end of the world.

As for the other shots, let's take a closer look. As for the third question, I am speechless. The problem of not being able to answer ** is the problem of the merchants.

The point-and-shoot camera is fully automatic, and you don't need to adjust the aperture, shutter, and other parameters, as long as you press the shutter directly on the person. It is a dual-lens camera, which differs from a 135 single-lens reflex camera, but also uses 35mm film.

Point-and-shoot cameras are also included within digital cameras.

Point-and-shoot camera - a camera with auto**, autofocus, autoloading, auto-rolling, auto-rewinding, automatic recognition of the sensitivity of the film used, and built-in flash auto-flash when the subject is low.

Digital camera - is the product of combining mature digital technology with traditional camera, because the direct function of digital camera is imaging, so the concept of digital camera must first be camera. So, let's start with the camera.

The camera category of digital cameras.

As an extension of the camera, the digital camera naturally also conforms to the definition of the camera. Simply put, it's the ability to image. In other words, there must be a lens – a vanguard that captures images.

Usually according to the change of focal length can be divided into two types: fixed focal length lens and zoom lens, fixed focal lens as the name suggests is a lens with an immutable focal length, and a zoom lens can adjust the focal length to achieve a good framing effect. The quality of the lens directly affects the image quality of the digital camera, and the overall performance and ease of use design of the camera are also very important. The advantages of traditional camera manufacturers naturally come to the fore when they incorporate advanced optical technology and manufacturing experience into digital cameras.

In an era where shooting quality is important, advanced optical technology will undoubtedly add a lot of color to digital camera users.

From the camera itself, it can be divided into SLR cameras and fully automatic cameras. The full name of SLR camera is single-lens reflex camera, and the lens of the general SLR camera can be replaced, and the photographer can choose different lenses according to different shooting requirements. Generally, professional-grade digital cameras are SLR cameras, which are more suitable for professionals because of their expensive construction and high quality.

For general work and life, you can choose a fully automatic camera with zoom, and different users can choose from cameras with different zoom factors such as 2x, 3x, and 10x according to their needs.

A point-and-shoot camera is actually a fully automatic camera, because when you take a picture with it, you only need to aim at the target and press the shutter, so it is called a point-and-shoot camera. Compared with other cameras, it generally cannot control the shutter speed, aperture size, ** degree, can not be equipped with other lenses, etc., the structure is relatively small and easy to carry.

Point-and-shoot camera can be understood as a lap automatic camera.

Its aperture is auto-iris and the shutter is available.

Digital Camera: His sensor system is different from that of the early point-and-shoot cameras, the early camera was film, and the digital was the image sensor CCD

Fools are one after another"Autofocus"In fact, it is a simple optical system that fixes the light, and it automatically charges the flash according to the surrounding light.

All you have to do is press the shutter below, and that's a general introduction to point-and-shoot cameras.

His disadvantage is that the realism is poor, due to the simple design of the point-and-shoot camera, it is difficult to shoot a good effect** Ruyi is damaged and has no repair value.

Pros: Simple and easy to use, convenient.

Digital cameras use high-resolution lighting elements to improve color reproduction and clarity qualitatively.

And you can call it up with the computer, and you can directly place the photo on the computer.

It's extremely easy to call.

The shutter of the digital camera can be freely adjusted within the settings allowed by the machine, and it can take a lot of artistic photos.

The aperture is mostly manual + digital and can be adjusted according to the photographer's wishes.

And so there are articles on the web about a large number of digital cameras that you can consult.

There are very few fools for the time being, and time will still exist at one end of the spectrum.

A point-and-shoot camera is a direct shot, as long as you can press the shutter, but it also belongs to digital cameras.

Digital cameras and professional cameras can adjust the aperture shutter in many aspects, and of course, the results will be better.

In the past, it was mainly a short-throw camera with a focal length of 28-35mm, and it was a fully automatic camera that could be photographed without focusing or adjusting the aperture

The point-and-shoot camera was the one that used to be, and now no one uses that kind of camera. But now, point-and-shoot cameras are used to describe cameras that operate fully automatically because they can't set the aperture.

shutter, and even white balance in some cases.

You can't set the fullness or anything. Or follow-up.

All fully automatic cameras can be called point-and-shoot cameras, such as the Canon Ixusis Sony T300

Sony T70, etc.

Of course, cameras with full manual functions are not called point-and-shoots: DSLRs, Canon A720 telephoto cameras, Canon SX100

Panasonic TZ15GK (TZ5).

Fujifilm S8000FD

Digital cameras are what distinguish them from traditional optical cameras. Traditional optical cameras use film for phasing, and digital cameras use electronic imaging for the original CCD

The general "point-and-shoot camera" (a few hundred dollars) is actually not a real "point-and-shoot camera", that is, a toy camera, the focal length, aperture and ** time are fixed; A real "point-and-shoot camera" does everything with a press of the shutter, and the effect is professional-grade, and this kind of camera costs thousands or even tens of thousands.

1. No aperture and shutter is not a camera, but a camera has an aperture shutter.

Second, the so-called fools can be used even if they are not professionals.

3. The so-called point-and-shoot camera is a camera that automatically metering and automatic filling light, and does not require strong professional knowledge.

Fourth, professional cameras also have a point-and-shoot function, I know that many professionals also use the point-and-shoot function, and the professional machine will be used as a point-and-shoot after adjusting to the P file, but it needs to be manually filled with light.

Before taking a picture, just a preview image is displayed on the screen, so as to tell you what it will look like

Let's spread it out a little bit.

For example, if you take a picture, the parameters are:

Aperture F8, shutter 1 160s, sensitivity 400 (if there are other special effects such as white balance, HDR, night scene), even if the above parameters are not set manually, the program is automatic, and the above parameters will still be calculated by the processor.

The image displayed on the camera display before taking a picture is a CMOS (image sensor) plus processor calculation, which simulates a picture that approximates the effect that is about to be taken**. It's just a simulation! After the actual shooting, the camera will mobilize the program to calculate and process the optical signal of the CMOS + various camera parameters in detail, and finally get a ** that really belongs to the parameter effect.

There are two ways to make the display screen exactly the same as the shot**, one is that the algorithm is extremely accurate! But technology hasn't reached that level yet. Another way is to keep the camera working, constantly taking pictures, computing and transmitting ** to the display screen in real time (that is, real-time recording), but in this case, one is that your camera memory and processor are unbearable, and the other is that the battery is unbearable, and the key CMOS will also shorten the lifespan.

That's why the manufacturer chose such a compromise approach. (Generally, mobile phones use a similar method to the second method, because the image sensor of the mobile phone is small, and the relative burden is also small, so what you see is basically seen.) ）

Optical cameras, that is, film cameras, have been produced for hundreds of years, and the technology is very mature. However, the development of digital cameras has only been a few decades now, and the technology is not yet perfect, so many cameras still retain optical viewfinders. However, the content of digital display is more and more valuable for reference, and it must be a direction for the development of the industry in the future.