APS photography system

APS is the abbreviation of Advance Photo System, and its Chinese name is Advanced Photography System.

APS replaced film and 35 mm photography technology. For those who devote themselves to digital photography, many advantages of APS are worth noting. Three pictures of APS film era

APS is positioned in the amateur consumer market, and ** has designed three negative frames (H, C, P):

APS-H (high definition) type, the picture size is 30.3× 16.6mm, and the aspect ratio is16: 9;

APS-C (classic) type, one end is blocked at the left and right ends of APS-H picture, the aspect ratio is 3:2, and the picture size is 24.9× 16.6mm, which is the same as that of 135 negative;

The APS-P (panoramic) type is to block one on the upper and lower sides of the APS-H picture, so that the aspect ratio of the picture is 3: 1, the picture size is 30.3×/kloc-0.1mm, and the aspect ratio is1:4.

Three frame sizes of APS

Considering the cost of production and research and development, most digital cameras use CCD/CMOS image sensors with APS-C frame smaller than 135 film, and only high-end SLR digital cameras (d SLR) use sensors with the same size as 135 film. In order to facilitate the distinction, people in the industry (to be exact, bookworm editors of some photography magazines) define the film size of 135 as Quan Huafu size, so there is a distinction between Quan Huafu and APS frames.

Three Frameworks of APS Digital Age

In the digital age, digital SLR cameras (DSLR) borrowed this standard, and called 22.5 x 15.0 mm and 23.6 x 15.8 mm close to the size of C as APS-C frames. 28.7 x 19. 1 mm is called APS-H frame. 135 film is equivalent to 36×24mm, which is called Quan Huafu. At the same time, some consumer digital cameras also adopt this specification.

The design idea of APS is: treat film as a disk.

In other words, film is used to save images and other information such as shooting time, shooting date, comments, camera setting parameters, etc. The captured images can be saved in various formats: 3.6 inches× 6 inches, 3.5 inches× 5 inches and 4 inches× 6 inches. The storage formats of panoramic photos are 3.5 inches× 8.5 inches and 4 inches×11.5 inches.

Cameras supporting APS can quickly switch the same film and take photos in different formats. You can change the film even in the middle of a roll of film. In addition, the film can be reused. Without exposing the film, the film in the film box can be rolled forward or backward.

APS has many incomparable characteristics compared with traditional cameras: it also uses traditional films, which need to be photographed, developed, made into negatives and finally printed on photographic paper; For APS, the film is rolled back into the film barrel after being developed. Users only need to select the photos to be processed, and they can scan them into the computer with special scanning equipment for processing. Just like using a digital camera. You can take the developed film home and handle it yourself without the help of the photo agency.

APS also needs to develop the film. Therefore, digital camera is the most important tool to generate digital images. However, APS promises to reduce the differences between film-based photography technology and digital camera technology that does not require film.

In a word, the development of APS technology shows that the future development direction is digital and computer-based photography technology, whether photographers use traditional photography technology or new filmless digital photography technology. 1) imaging size and imaging angle.

The imaging size of a photo is related to the focal length and the distance between the subject and the camera. Under the same conditions (the same Quan Huafu lens, the subject with the same distance), because the sensor size of APS-C format is smaller than that of Quan Huafu, the viewing angle is smaller, and the photo contains less content than that of full-frame camera. Let's take a look at the photo comparison between Quan Huafu and APS-C format:

Figure 1 Differences in shooting distance, photo angle and content of lenses with the same focal length

Fig. 2 The photos with the same focal length and the same shooting distance have different effects.

From the comparison of the two pictures, it can be concluded that the viewing angle of the photo obtained by APS-C is smaller than that of Quan Huafu (Figure 1), and the object displayed in the same size photo in APS-C format is larger than that in Quan Huafu (Figure 2).

According to the specific dimensions of APS-C sensors used by different manufacturers, the equivalent magnification of APS-C sensors is different, Canon is 1.6x, Norcon is 1.7x, Olympus is 2.0x, others are1.5x ... When APS-C camera uses a full-frame camera lens, the actual viewing angle is the same as that of a full-frame camera. For example, an APS-C camera with a 50mm Quan Huafu lens has the same viewing angle as a full-frame camera with an 80mm lens (calculated by APS-C frame magnification 1.6X). This is a theoretical value, but in fact there is still an error.

The above situation will only occur if APS-C camera uses the lens of full-frame camera. At present, a special wide-angle lens for APS-C camera has been developed to solve the problem of insufficient viewing angle at the wide-angle end.

2) Is APS-C frame with 50mm lens really equivalent to full-frame 80mm lens?

For example, EOS 30D(APS-C format) is equipped with 50/ 1.8 lens, which is equivalent to 80/ 1.8 lens. However, when 50/ 1.8+ EOS 30D and 80/2+EOS 5D (Quan Huafu) are shot in the same plane, the depth of field and out-of-focus imaging of 80/ 1.8 are still 50/ 1.8, which is not equal to 80/2. The appearance of equivalent magnification, except the effective viewing angle, has not changed the three main parameters of maximum aperture, depth of field and perspective relationship. Will not change the focal length of the lens! !

conclusion

For friends from traditional SLR, if you want to shoot a good wide angle with APS-C format digital camera, please have a special APS lens. Remember to take a few more steps when shooting. Or go directly to Quan Huafu DSLR to save trouble.

Friends who have never used traditional SLR and directly used digital SLR need not consider the above problems. APS is the abbreviation of Advenced Photo System, which is called advanced photography system. This new camera system is jointly developed by Kodak, Fuji fujifilm, Canon Canon, Nikon and Minolta. At the same time, this is also the great unity of the photography industry, and the determination to win is quite obvious, including film, camera and printing. The technology of this system is aimed at some changes and improvements of the existing photography system. In essence and concept, it basically extends from the past photography system. Its foresight lies in becoming a bridge between digital images and traditional mechanical images. As far as the convenience of using APS is concerned, it allows more people to take more photos, which is why a new system has attracted so much attention from the photography industry.

To put it simply, the biggest difference between APS system and traditional film is that there will be a track area and an optical code on the film, which are used to store light and main body in a data way, including some photographic data and scene distance, shooting date and time, etc. When the film is developed, the data will be sent to the printer, and the quality will be more stable. It also shows the possibility of digital communication.

APS is considered as one of the most creative products in Europe and America in 1996, but its previous performance in Taiwan Province Province was much cry and little rain. But judging from the market reaction of Europe, America and Japan, it is undoubtedly the future trend.