Does residual frame refer to half frame or aps-c frame?

The residual frame is also called half frame, which refers to the APS-C frame.

The frame size has nothing to do with 2k or 4k. Frame refers to the image sensor size. 2k and 4k refer to the resolution size of the image.

The so-called residual frame refers to the APS-C format. This standard was originally born in the film era. Its original meaning was Advanced Photo System (Advanced Photo System). In 1996, it was developed by Kodak, Fuji, and The five major photographic equipment manufacturers Canon, Minolta and Nikon have introduced specifications for a new generation of photographic systems that are different from the 35mm film system.

As we all know, before this system was fully implemented in the film industry, the digital wave hit, and film was killed, and it failed to become popular. However, because the frame is smaller than the full frame, it has technical and cost advantages in sensor manufacturing, so it has been utilized and promoted by digital cameras, becoming the first choice for entry-level cameras.

There are three standards for APS systems. The most common one we have is the APS-C standard. The size of each company's CMOS will be slightly different, but it is generally around 25.1*16.7 mm.

Extended information

The difference between full frame and partial frame

The advantages of full frame over APS-C frame mainly include the following points:

Focal length conversion factor 1.0, convenient for lens selection and use.

2. Advantages of the wide-angle end. After all, it is very difficult to achieve 8-12mm with a reverse telephoto structure lens, while a full-frame SLR lens with a physical focal length of 14-18mm will obviously be more capable in this regard.

3. High ISO advantage. A larger photosensitive area can bring better signal-to-noise ratio.

4. Dynamic range advantage. Another product that comes with high signal-to-noise ratio.

5. Resolution advantage. The full-frame sensor utilizes a larger lens image field, which relatively reduces the pressure on the lens on small area resolution, thereby achieving better physical resolution performance.

6. Depth of field advantage. The same angle of view requires a longer physical focal length on a full-frame sensor, allowing for a shallower depth of field.

7. The optical viewfinder module of the full-frame camera will also be larger, which seems to have a wider field of view and a more comfortable viewing experience. Of course, the only full-frame mirrorless camera currently uses EVF—which can actually provide a better viewing experience than an APS-C SLR.

8. More professional control and body settings. This usually appears on high-end full-frame models.

Full-frame cameras are not perfect - compared to APS-C format models, they also have their own disadvantages:

The lens cost is higher. Large image field lenses have higher manufacturing costs.

2. Since the telephoto end does not have the 1.5-1.6× conversion factor, it will appear to be slightly disadvantaged.

3. The body and lens are larger than the APS-C format and are relatively less portable.

4. When using the same model of focusing module, the focus point coverage will become smaller, which will cause certain problems in focusing.