I will show you how to open a catalog lens from the files in OSLO.  There are many lenses from several companies available.  There are some very good achromatic doublet lenses which you might want to examine.  You can select any of these lenses, you might even want to buy one.  But if you want to make a lens these catalog lenses are a good starting point to see professionally designed lenses.  It may be helpful to see how good the images are in these lenses, and to learn what glass types have been selected for a particular type of design.

  Let's start by opening a new lens.

  Click on Datalog lens, then OK.

  This is the window where you can select a catalog lens to evaluate.

  On the bottom left is the catalog.  You may select a different catalog, or all these catalogs by clicking on COMBINED.

  Near the center of this window I have clicked Doublets.  The default was Singlets.  You may sort these by focal length (EFL), or by Diameter.  You can select a lens by clicking on a lens listed over on the right.  You can scan up or down to find a lens which is close to your diameter and focal length needs.

  Click the green check mark on the left side, about half way down the window.  This will accept the lens you have chosen.

  Your lens will show up in the Surface Data window.  You will notice that the individual radii, thicknesses and glass types are not shown.  You can still evaluate the lens and save the file if you want to.  But, I will show you how to display the lens data in more detail.

  Click on the grey box under RADIUS for this lens.  I have drawn a red arrow, this is where you mouse cursor should be placed.  When you click here you will get a confirmation window.  Click OK to ungroup the surfaces for this lens.

  Now you will see the data in the Surface Data window.  This is still the same lens, but it is displayed so you can see it, and modify it if you like.