dbOptic: More information and screen displays . . . .
Spot Diagrams . . .
and encircled energy plots . . .
Unique "Double-Star Test" . . .
The XY Plot Menu Command allows the plotting of aberration vs surface design parameters, object distance or wavelength. The red plot below shows how system spherical aberration LA' varies with radius of curvature of surface number 4, the primary mirror of a 1000 mm focal length telephoto mirror lens. The horizontal gray line represents LA' = 0 (fully corrected). The horizontal green lines represent the allowable tolerance values. The short red vertical bar represents the system as currently designed with R4 equal to about -419mm. The plot clearly shows that while LA' is within the allowed tolerance, it could be reduced further by flattening the surface slightly to about R = -423mm.
New imaging of Extended
Objects available beginning with Version 2.0 . . .
Instead of using a single point as the object for a spot diagram, we consider an
array of object points at the same finite or non-finite object distance and create a composite spot diagram at the image plane. The
composite image of this "object map" provides a near-realistic view of the image
that a candidate optical system might generate.
Original object from file.
Image generated by tracing object
array through a well-corrected 76mm f/5 achromat.
The images below show an
original object file and resultant "expected" images from two different lenses after tracing 80 rays through each of the 10,201 object points making up the
original object:
