I'm getting ready to get a HVL-20DW2 light for one of my backup cams (VX2100)...Since the 2100 has a hot shoe, can I safely mount the light or do I have to isolate the mount with tape or some other material...

I use that light in the hotshoe of my PD170 with no problems. It fits firmly in the shoe.

Actually the shoe on the 170 is a cold shoe....

Oops, you're right. However, the light fits firmly in my TRV-900's hotshoe (as well as in the 170 cold shoe), using the light's mounting screw to tighten it against the shoe bracket. I would expect it to fit fine in the VX2100, but I have not used the light with that cam.

My only concern...and may not be an issue at all...is the voltage present at the shoe and what happens when a unit in placed in there that is not designed to pull voltage

Mark,
The hotshoe on the TRV-900 has a spring-loaded cover over the metal contacts. This cover does not retract when the Sony light slides into the shoe, so there's no voltage effect on the cam one way or the other. Also, the foot on the HVL-20DW2 is plastic anyway.

Duh...I should have remembered that...I have another one that is actually mounted to a metal/adjustable mount....so bieing plastic, it is not an issue at all :-)

Thanks..........

And while we're talking about that little light, some tips.

Always use it in ther twin lamp mode as this softens the shadows very effectively. Rather than having a point source of light, you've almost got a 2" x 1" light source.

Next, well worth getting a Lumiquest Mini Softbox. it velcros quickly into place, absorbs a stop, but at the same time softens the light yet again, and makes you much more popular ar parties and wedding receptions.

tom.

Or you can just buy a sheet of diffusing gel and tape a bit across the lens of the lamp. Much less expensive and easier to manage. than a softbox. You can get different levels of diffusion so you can fine-tune the effect.

This is what the ENG camera operators do all the time.

Good advice, Tom and Mike. I use Rosco "tough white diffusion" (#3026) gel. The Sony light is a good value and, since it uses Sony batteries, easier to manage than more expensive camera-mounted lights. Using gels or the mini softbox provides almost as much light control, too.