When it comes to the lens, you have to mention the aspherical lens. In many people's understanding, the aspherical lens is a symbol of high level, and the advanced lens is almost all aspherical lens.
Let's start with what is called a aspherical lens. The aspherical lens is contained in the camera lens, aspheric is often calculated according to the surface, some aspherical lens side, the other is not, or both sides is spherical, and so on.
In general, a lens with two or more aspherical lenses is a very advanced lens. So, is the aspheric surface a very difficult technique?
We can look at it from the other side.
Now, in terms of glasses, the aspheric surface is also very widely used, and in fact, it is no more expensive than the spherical lens. For numerical control grinders, the wave surface can also be made.
Clearly, many people's understanding of the aspheric surface is still stuck in the leica 501.2 myth, which itself has long since been broken.
Of course, many people would still use the so-called "grinding aspheric", but don't say what grind the aspheric surface. I believe that for many people, it's impossible to tell whether a picture is not a spherical lens.
Is the aspheric surface necessarily good?
Even if it's a cock shot, it's impossible for each lens to be aspherical, the aspheric lens is actually a supporting role in the lens, not the main character, the main corrective, the correction function, after the use of aspherical lenses, the image of the edge of the image will be solved well and the picture will be more average.
So, is it a good thing to have an aspheric surface? From the current situation, the use of aspheric surface technology has become the standard configuration, especially the high technology index lens, for example, large aperture wide-angle zoom lens, it is difficult to guarantee the quality of the picture without the aspheric surface.
But in terms of our film fans, the aspherical lens we can use is relatively limited, after all, we use the camera mainly concentrated in the last century 60-90s, until the 90s, aspherical lens or less. Here we're talking about 135, and less in 120. We have seen that CAI has built so many classic Hau shots, such as the 384.5 on SWC, and there is no aspherical lens.
In a series of SLR lenses designed by Mr. CAI for nikon, many of them have no aspheric surfaces. But it doesn't prevent these lenses from being a good shot, like chase 50, 1.4 SLR, and the picture is average.