Eljen vs. Cargille

The spectrum of the detected photons with using Eljen EJ-550 and Cargille 0607 as the optical grease.
Bars with 3-layer lens.
Optical grease thickness assumed (prism-MCp): 0.5 mm
1k Kaons @ 3.5 GeV/c and 25 degree polar angle
Usage of the Cargille adds about 15% of hits.

Refraction and absorption of the Cargille with comparison to other materials:

The spectrum of the detected photons: