What is a paraxial camera?

Because the viewing optical axis is located beside the optical axis of the photographic lens and parallel to each other, it is named "paraxial" camera.

Because the framing structure is independent, the scenery seen by the viewfinder is only roughly consistent with the scenery shot by the lens, while the framing of the SLR is directly through the lens, and what the viewfinder sees is shot by the lens. Because what you see is not necessarily what you get, but what you see is what you get.

In addition, paraxial cameras can't see the depth of field and brightness of light, while SLR can see the contrast between depth of field and brightness of light through the lens, so beginners can easily judge different aperture shutter combinations and different depth of field.

Like SLR, the paraxial lens can be changed, but almost all SLR lenses can be changed, and the paraxial lens can only be changed for high-end goods, such as Leica, Zeiss IKON, CONTAX G, HEXAR RF, Minolta CLE, Fu Lunda R and other general paraxial lenses are fixed.

The advantage of paraxial contrast SLR is that the focal plane is closer to the lens and the flange distance is shorter, so paraxial has unparalleled advantages in wide-angle and ultra-wide-angle lenses. Just look at the data evaluated by Hasselblad Lab. In the field of super wide-angle lens, the paraxial axis is basically on the list. Because there is a reflector in the SLR, the lens is far from the focal plane, and the corner imaging of the wide-angle lens is poor (the wider the angle, the more prone to dark corners, because the amount of light entering the lens edge is insufficient. At this time, the closer the focal plane is to the lens, the less the light loss can be. This is a structural limitation, and the lens design and manufacture on the paraxial and the same level SLR cannot be changed. In addition, there is no reflector on the side shaft, so the fuselage is smaller and lighter than the SLR.

The disadvantage of paraxial contrast SLR is that it is also a focal plane problem (the shorter the flange distance, the better the wide angle, and the longer the flange distance, the better the medium telephoto), which leads to the imaging of paraxial in the medium telephoto is not as good as SLR. In addition, due to the structural limitations of the paraxial viewfinder, for example, if a 135 focusing lens is used, the viewfinder of Leica M6(0.85 magnification model) has only one fingernail size. Therefore, without some experience in focusing and composition, it is basically impossible to shoot. In addition, there are few zoom lenses on the side shafts (so far, the side shafts of all brands add up to less than 5 zooms), because it is difficult for the viewfinder to judge what focal length the lens is in when zooming, which is very good for SLR. Take the lens directly, and the viewfinder of the lens will present the focal segment truthfully. In addition, it is not as good as SLR in the visibility of depth of field, the judgment of aperture shutter combination by light change, and the composition of WYSIWYG.

Generally speaking, sideline is suitable for people with strong photographic skills. Because what they see is not what they get, they need to accumulate some experience in photometry, ranging and composition in order to operate freely. But then again, the advantage of the paraxial axis is wide angle, especially Leica is a well-deserved emperor in the humanistic photography of the 35-focal profile, and it is very worthwhile to punch wide angle. Because no matter how awesome a photographer is, there will always be a 2 1 ultra-wide-angle Leica with a focal length of 35 or more to solve the problems that SLR can't solve.