isolampsic point

Same as isoemissive point.
Note:
The term derives from the Greek words isos: equal, and lampein: to emit light or to shine. Isolampsic is thus parallel to isosbestic.
Source:
PAC, 2007, 79, 293 (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 358