I was going to investigate the lens flare
problem this evening. This was going to
require keeping the shutter open for quite
a while, so I decided it was time to do
another job I've been putting off -- measure
the power consumption of the TL120.

The TL120 uses two SR44 (aka 357s) button
battery cells in series. The batteries are
rated (when new) at 1.55V and 150-170mah

My (fairly fresh) batteries are currently
producing 3.2V at no load.

My measurements (taken with my 25 year old
analog VOM) indicate the following currents:
meter active 5ma
shutter open 25ma

I wanted to see how long I could expect these
batteries to last in the TL120. I went looking
for discharge charts for the SR44 cells and was
very disappointed. The currents I measured are
far in excess of any of the web-published charts
I could locate for the SR44. My best estimates
are based on data from EverReady's web site
http://data.energizer.com/PDFs/357-303H.pdf
and fiddled with my pocket calculator.

I figure the battery set is good for 6 or 7 hours
of continuous shutter open before it falls
to 2.6V. The question now is, at what voltage
does the shutter circuit quit working?

With that bunny trail out of the way, I'll
go point my camera at some lights and see if
I can reproduce the flare.
________________________________________
John Thurston
Juneau, Alaska
http://stereo.thurstons.us