Why is the picture quality in Showa Kamen Rider not good?

It may be because the shooting technology or film and television equipment is not very good.

Image quality: it is the image quality. Including clarity, sharpness, distortion, dispersion, resolution, color gamut, color purity, color vividness, color balance and other indicators. Sharpness: sometimes called "sharpness", it is an index reflecting the sharpness of image plane and edge. If the definition is increased, the detail contrast on the image plane is also higher and looks clearer. For example, in the case of high definition, not only the wrinkles and spots on the face on the screen are clearer, but also the protrusions or depressions of facial muscles can be lifelike. On the other hand, dark lines or black lines in the vertical direction, or places where black-and-white images suddenly change, in the case of high sharpness, the edges of lines or black-and-white images suddenly change more sharply, and the overall picture appears clearer. Therefore, improving sharpness is actually improving clarity, which is the good side that people need.

Lens distortion: Generally speaking, lens distortion is actually the general term for the inherent perspective distortion of optical lenses, that is, the distortion caused by perspective, which is very unfavorable to the imaging quality of photos. After all, the purpose of photography is reproduction, not exaggeration, but because it is the inherent characteristics of the lens (convex lens condensing, concave lens diverging), it can not be eliminated and can only be improved. The optical design and materials of high-grade lenses are exquisite. Using the optimized design of lens group and selecting high-quality optical glass (such as fluorite glass) to make lenses can reduce the perspective deformation to a very low level. However, it is impossible to completely eliminate the distortion. At present, the best quality lenses are tested under extremely strict conditions, and the edges of the lenses will be deformed and distorted to varying degrees.