A couple of weeks ago, the subject came up again of battery
usage in the TL120 medium-format camera. Since I hadn't
measured the current drawn by my new camera, I pulled out my
electrical meter and . . . . smoked it. I'm not exactly sure
what happened but it's toast.

Since I paid $12.95 for it in 1977, I figure I've gotten my
money's worth from it and ordered myself a new Fluke DMM. It
arrived today, I'm quite happy with it, and I've got some new
measurements on the TL120

The meter draws 9ma
The shutter draws 28ma

We are talking seriously _low_ current draw here. There is
no reason to expect the batteries not to supply 6 or 7 hours
of continuous shutter operation.

I can detect no current when the camera is sitting hands-off.

Funny thing is, I do detect a current during the shutter cock
stroke. It is only during the shutter cock (not subsequent
film winding strokes) and it is very brief. If I pull the
lever _very_ slowly, I can find a point in the shutter cock
where a full 28ma is drawn and then ceases as I finish the
stroke. It doesn't concern me, but it is there and it is the
only other way I can make the TL120 draw power.

It shouldn't hurt anything (except, maybe, the threads on the
battery compartment) to loosen the battery cover when the
camera isn't in use, but I will certainly not be making the
effort on my cameras.
________________________________________
John Thurston
Juneau, Alaska
http://stereo.thurstons.us