Geometry - Insert Lens from Catalog

Navigation: Geometry > Lenses and Mirrors > Insert Lens from Catalog

Insert Lens from Catalog

Page Contents

Description

•Lens units

Description

This dialog allows insertion of a catalog lens into the current FRED document. The lens is inserted with the location and orientation specified in the dialog.

Navigation

This command can be accessed in the following ways:

•Right mouse click on the Geometry folder in the object tree and select "Insert Lens from Catalog" from the list menu

Controls

Control	Inputs / Description	Defaults
Lens Catalog	Shows selected vendor catalog.	Edmund Industrial Optics
Lens List	Shows lenses available from vendor selected in the Lens Catalog list.	Edmund Industrial Optics lenses
Flip lens on import to reverse surface order	When toggled, the imported element will be created in a reversed orientation. See the Lens Reversal application note below.	Untoggled
Lens Location and Orientation	Shows Location and Orientation modifiers that will apply to lens when placed in the FRED document.	Parent = Geometry Type = Make coincident with another coordinate system

OK	Accept settings and close dialog box.
Cancel	Discard settings and close dialog box.
Apply	Accept settings and keep dialog box open.
Help	Access this Help page.

Application Notes

Lens units

FRED inserts the lens using the units provided by the vendor. Currently, in all cases, the units are millimeters. If this is not the unit of measure for your system, the lens is scaled by the appropriate factor when imported.

Lens Reversal

An important characteristic of the lens import reversal feature is that the process is not equivalent to importing a lens and then reversing it by 180 degrees using a position orientation specification. For example, the image below shows a plano-convex lens imported and then rotated about the Y-axis by 180 degrees with the local coordinate axes of the lens drawn.

There are a few things to note about the above graphic. First, the local +Z axis of the lens element is pointing towards the left. Second, in a conventional layout when rays are traveling from left to right, the rays will encounter Surface 2 of the lens element before encountering Surface 1. Third, since the origin of the lens element is located at Surface 1, you would need to add an additional Z shift to the lens element in order to locate the plano surface where the origin of the lens is currently being drawn.

Now we show the same element imported into FRED with the lens reversal option checked. The resulting lens is shown in the graphic below.

Note that in the above graphic, the plano surface is now Surface 1 on the object tree, the +Z axis points to the right and the concave surface is now Surface 2. This type of reversal is typically easier to work with for model construction purposes due to the coordinate system convention and lack of additional rotation and shift operations needed to place the element.