Quote Originally Posted by jp498 View Post
Rather than a resistor, I'd put a diode (of ample capacity) in series with the lamp. I'd wire one up, but there used to be little discs for that purpose that went into lamp sockets.

It's not the end of the world if you blow a bulb. Keep a spare in stock, and if they are no longer available adapt to another bulb or fashion something with an LED bulb.
Diodes don't do the right job as discussed above. I have the knowledge but not the mechanical skills to fashion something so I bought an LED light source from this fellow:


Seems to work great for black and white. I doubt its spectrum is good for color but I've enough 211s for when I start that again.

I may eventually get his complete VC head when I have the iPad to run it, or a revised iPhone, but that's a chunk of change right now. The light source works great on my D2.