Why a 1.45V Hearing Aid Battery Makes Your Film Meter Read Two Stops Off
Zinc-air hearing aid cells sit at 1.45V open-circuit but sag to about 1.2V under a CdS meter's load, so a mercury-calibrated meter reads 1.5 to 2 stops off.
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2 articlesZinc-air hearing aid cells sit at 1.45V open-circuit but sag to about 1.2V under a CdS meter's load, so a mercury-calibrated meter reads 1.5 to 2 stops off.
A motor-drive camera rewinds a full roll when it cannot confirm film advanced. A slipped sprocket, DX code reading ISO 0, or low battery voltage triggers