Re (2): Voltage halver.

In article <vhct0j9ao9d75ad7dr47r4eha1t9knt5d2@4ax.com>, legg <legg@nospam.magma.ca> wrote:

What does the microscope manufacturer supply for this function?

The scope is a Zeiss OPMI 1.  Google finds many listings of various
models with various power supplies. 

This scope was donated without the power supply; I can't say what the
original supply was but Zeiss built nice equipment capable of
continuous and reliable duty.

If you have a >6V source, simple 555-type buck regulators are
 available with minimum output listed as 1.8V
 
https://www.aliexpress.com/item/1005006482720286.html?
 
These generally regulate the negative output terminal, unfiltered.
This would not be an issue for an isolated 6V incandescent lamp.

Good idea.  Will see what Lee's Electronics has in stock. I expect to
have to limit the voltage somehow to prevent burning the bulb.

Thanks,            ... P.