Oftentimes, you will be utilizing multiple glass catalogs in a single lens system. It may not always be obvious which glass catalog is being used for each glass surface/object in your system. This is especially true when glass data with a given name is present in more than one loaded glass catalog.

When you type in the name of a glass for a sequential surface or non-sequential object, ZEMAX looks at the list of the glass catalogs loaded in the “Glass Catalogs” tab of the General dialog. This dialog can be accessed from the menu option, “System > General”:

When there are multiple catalogs loaded in this dialog, for each glass specified in the Lens Data/Non-Sequential Components Editors, ZEMAX will search the loaded catalogs from left to right. Once ZEMAX finds the glass specified in a loaded catalog, it will stop its search. Thus, if you specify a glass that exists in more than one of the loaded catalogs, the leftmost of those catalogs is where the data will come from.

When using ZEMAX, there is an easy way to determine which catalog a specific surface’s/object’s glass data is coming from. Simply click on the “Glass” (sequential) or “Material” (non-sequential) column of the appropriate editor and then open the Glass Catalog dialog. There are three ways to open this dialog:

• Press “F4” on your keyboard
• Click on “Gla” in the button bar at the top of the screen
• Select the menu option, “Tools > Catalogs > Glass Catalogs”

No matter which method you select, ZEMAX will open to the specific glass data entry that it is using for that particular surface/object: