Seen a few comments here about reading markings on chips with side lighting and I do have a nice IKEA LED gooseneck light for that purpose but it is a pain to work around so I decided to try something easier.
Made a simple clip-on ring on the light ring that is friction held and can be turned to the optimal position. It is also straightforward to remove but I find that I leave it on all the time.
The holder was done with a standard 3D printer to match my fiber light ring and hold the polarising film against the light source. The two side tabs are friction fit to the sides and act as handles to rotate the assembly.
First, photo shows the arrangement.
Second, photo is how it fits.
Third, photo normal lighting.
Fourth, with polariser.
I am also waiting for a good camera lens polarising filter of the right diameter to add at the objective input to increase the contrast further. A trial with a film polariser in the optical path messed up the image sharpness too much. That is less relevant for the light ring of course.
But as a an easy mod this first step works better than I thought it would.
Cheers.