A practical comparison between the methods of determining the focal length of a convex lensdoi:10.32792/utq/utjsci/v6i3.35Al-musawi, Thill A. KathumJournal of Thi-Qar Sciences
Lenses with longer focal lengths, such as 200mm, give you narrower angles of view. The focal length of a lens is the optical distance (usually measured in mm) from the point where the light meets inside the lens to the camera’s sensor. “You can zoom in on your phone, but that’s...
The following equation, called lensmaker's equation, allows one to calculate the focal length of lens made of a material with refractive index n and with curvature radii R1 and R2 on the two surfaces: The curvature radii are taken positive for convex surfaces and negative for concave surfaces...
An eyeglass apparatus having a variable focal length lens and an associated method for varying the focal length of the lens uses a lens having a focal length which is variable as pressure along the lens is varied. Focal length adjusting mechanisms carried by the eyeglass frames provide for manua...
Any least-squares optimization process would struggle to estimate the focal length and pixel pitch as separate quantities for each dimension. From that perspective, it seems practical to bundle these effects together into \(f_x\) and \(f_y\) terms. However, now we've tried to conflate our...
For the on-orbit space zoom camera, the camera focal length is in a constant process of change; accordingly, compared with calibrating other camera intrinsic parameters, calibrating the focal length has a practical significance for the s... Gaopeng,Zhang,Hong,... - 《Applied Optics》 被引量:...
a photographing lens wherein a convex surface thereof faces said object and satisfies: 18≤f≤32 and f2/90≤F≤16 wherein f is the focal length of said photographing lens and F is the F number of said photographing lens; at least one diaphragm; and ...
By semi-calibration we mean that all camera intrinsic parameters but a fixed focal-length are known. This scenario is quite common (not restrictive) in daily camera use. For example, except for the case where the camera lens is allowed to zoom continuously, it is often practical to assume ...
19. An instrument which incorporates a crystal diffraction lens, the improvement comprising means for varying the focal length of said lens to provide a lens with any one of a plurality of predetermined focal lengths, said means including means for changing heat transfer within selected portions of...
This means that increasing the NA of focusing lens is the most efficient method to decrease the spot without a strong sidelobe. Correspondingly, a high NA lens usually implies that the large size is required if we pursue a long focal length that is much preferred in practical applications. ...