The answer is highlight clipping. Do it.

Thursday night. Working on glare (lens flare) and caustics (light reflections off shiny objects).




Looks pretty good.

Trying it out on glass materials. Nice caustics, no glare.



Trying again.

Trying again.

Trying again.

Still not working. Maybe it's the caustics in the way?



Still not working.

Maybe it's the glass. Back to chrome.



Still not working. Completely unable to replicate image I made a few hours before.

Friday morning, glare is back. And on glass!



Now glare with caustics?

No.

Just glare again?

No.

Caustics first, then glare?

No.

Friday evening. I am still trying.



And it WORKS. Everything. All together.

It even works TWICE IN A ROW, from scratch.



I had my exposure curves set to preserve highlight detail. Except for glare to work, there needs to be blown-out highlights. I must have adjusted it once, without remembering, and never set it back right.

The end.