non/optically generated

“Optically generated” refers to an effect generated by light passing through the lens(es) of the camera or device.

“Non-optically generated” refers to visual effects that were not generated by light passing through the lens(es) of the camera or device.

In the 21st century, “non-optically generated” usually describes effects created by software or AI, whether in a computer or in the device that records the photograph.

There are many situations in which photographs made with “optically generated” effects can qualify as TTG—

— while identical-looking photographs in which the effects were “non-optically generated” are disqualified from TTG.

See the page “seen vs. simulated” for more on this.