I have a conflict with any shaders if I am flying on the helicopter or large plane. When I press F5 everything is getting darker!
In the first screenshots without pressing F5 on the helicopter and large plane


But in the second screenshots with pressed F5 on the helicopter and large plane
Everything is getting darker!


And on the plane (not large) I haven't got this problem.
I use:
Simpleplanes-1.16.4-4.1.2
Forge: 1.16.5-forge-36.1.2
OptiFine_1.16.5_HD_U_G7
And some other mods that may not apply to this issue.

Works as intended. I won't fix optifine bugs.