Industrial News

　　About the principle of fisheye lens,No matter what,the edge lines of fisheye lenses are curved,even for 90-degree fisheyes.This kind of distortion can be seen in many wide-angle lenses,and this is the obvious barrel distortion.The same 120-degree fisheye looks more curved,and more scenes are accommodated in the range;the same is true for 150-degree fisheye,and the 180-degree fisheye can capture all objects within 180 degrees around the lens.go in.As we all know,the shorter the focal length,the larger the viewing angle,and the stronger the distortion caused by the optical principle.In order to achieve a super large viewing angle of 180 degrees,the designer of the fisheye lens has to make a sacrifice,that is,to allow the reasonable existence of this distortion(barrel distortion).As a result,except for the scene in the center of the picture,the other scenes that should be horizontal or vertical have changed accordingly.It is also this strong visual effect that provides opportunities for imaginative and challenging photographers to showcase their personal creativity.

　　Structurally speaking,the fisheye lens is indeed similar to the fisheye structure,and there are two types of fisheye lenses,one is called Circular Image Fisheye(circular fisheye),and the other is called Full Frame Fisheye(full frame fisheye).The circular fisheye is the originator of the fisheye lens.Its designed viewing angle is basically above 180 degrees,so only the circular part can be seen in the picture.This kind of lens generally has a super large front group lens,and the lens curvature is very large(In order to collect light from more directions),the natural cost is also extremely high.At present,few manufacturers continue to produce circular fisheye lenses,which is mainly due to cost considerations.

　　The central design idea of the fisheye lens is to have a larger spherical radian(similar to the spherical crystal of the fisheye),and the imaging plane is closer to the lens(the distance from the crystal of the fisheye to the retina is very close).The angle of view of the fisheye lens can be close to or exceed 180 degrees.For a 135-frame camera,the focal length of the fisheye lens is mostly between 6-16mm,and the angle of view is generally around 170 degrees.Due to the large angle of view,the barrel bending distortion It is very large,so the straight lines around the frame will be bent,and only the straight lines in the center of the lens can keep the original state.