I refuse to use the old school fiber optic hose that is illuminated by a hot tungsten bulb inside of a box with fan, even though I do have several of these.
What I have been using for several years is an Ikea Jansjo desk lamp. I improve it by adding a lens (a cheap loupe you can buy in a set at Harbor Freight). This is acceptable, but not terrific. The biggest liability is that you have to keep repositioning the lamp. It either gets bumped out of position or you look at objects of various heights.
Hence this project. In a nutshell I disassembled a Convoy S2+ flashlight and am using the flashlight head (reflector and LED emitter). I choose the 4000K version of the light, which has a CRI of 95. You do not want the blue 6500K version. I removed the little circuit board with microprocessor and current limiting circuit and am building my own external control.
My microscope is an Olympus SZH10. This microscope has a cavity for some accesssory with 4 threaded (metric) holes. This is behind the objective and provides a nice place to mount my illuminator. I machined an aluminum plate and after making careful measurements I 3d printed a "bracket" to hold the LED head at a 45 degree angle. I didn't expect to get it right the first time, but I did.
Tom's Mineralogy Info / tom@mmto.org