That photo is over ten years old! I think I still have one fiber optic ring light running here at work, all the rest have been
swapped over to LEDs. The real issue with the fiberoptic ones is the lamps have a pretty limited lifetime. Hardly any of the
researchers think to switch them off.
In fact that is my one metric to gage if a researcher is really a stand-up guy. They turn off the microscope light when they're done with it.
Also the fiberoptic ones do put out a *lot* of heat. OK in the winter, but....
One trick for mounting the lights is that they made flat clear plates to mount to the threads on those microscopes. They way they're
made, there's a lip (has knurling, to tighten it in place) which can be used to mount another ring that the light mounts to. I like them because
I do a lot of soldering under the microscopes, and the flux blows off and gets on the optics. Cleaning the flat plate is easy, it's sort of sacrificial.
They also make + and (-) lenses to mount under the objectives. The (-) lenses increase the working distance even more.