Lens Entry

This section shows how to enter lens data in OSLO.

Lens Specification

The following lens prescription describes a cemented achromatic doublet. In a cemented doublet, the second surface of the first lens is the same radius as the first surface of the second lens, so that the pair can be joined in intimate contact. The interface between the two elements can then be entered as a single optical surface.

where

Procedure

1. Select File - New from the menu. This brings up the following dialog:

   

   Enter doublet for the file name and 3 for the number of surfaces.

2. Press the OK button and the surface data dialog should open:

   

   Click in the upper-left field that says "No name", and enter achromatic doublet. This will be used as a title on drawings. Enter 7.5 mm for the Entrance beam radius.

3. Click the options button in the GLASS field for surface 1 (AST). A pop-up menu will appear. Drag to Catalog, then drag right to Schott to select the Schott catalog.

   

4. Select the glass BK7 from the list of glasses

   

5. Continue filling in the spreadsheet table with the data from the lens prescription. When you are finished, the dialog should look as follows:

   

6. Click the OK button to accept the changes.

7. You may now wish to draw the lens. Select show - lens drawing from the menu and click the OK button on the resulting dialog. A plot like the one below should appear in a graphics window:

   

   Note: There is a toolbar shortcut for this operation. To find it, let the mouse cursor linger on each of the toolbar buttons. A brief description of each button should appear. Look for the one that says Draw the lens in plan view with default rays

8. You may wish to save your lens at this point. Select the File - Save As menu option to bring up a Windows common save-file dialog box.

Maintained by John Loomis, last updated 11 Sept 1998