You can finally say, “cheese,” again, with some of this Wein

Congratulations; you’ve just purchased a vintage Gossen® Luna-Pro® light meter complete with Variable Angle Attachment, in near mint condition, for a ridiculously low price. You immediately head over to Mike Butkus’ Web site and download the meter’s manual. [Naturally, you mail $3 to Mr. Butkus for payment for using his valuable service.] Armed with the manual you begin to study the instructions for the operation of the Luna-Pro.

Suddenly, GASP! In horror, you read the following battery information on page 7:

“To replace the batteries, unscrew the cover of the battery chamber (21) — a coin will be useful for this. Mallory PX 13 or PX 625 batteries may be used.”

Your knowledge of vintage camera and light meter batteries is sufficiently informed that you know these referenced batteries are discontinued mercury cells. While you momentarily consider substituting contemporary alkaline replacements, you also realize that mercury batteries were 1.35V. Drat; today’s 1.5/1.55V replacements just won’t work. Now, what?

Well, you could cry, but it’s better to Wein

Thank goodness for Wein Cells. Yes, Wein has a long history of making mercury battery replacements for vintage cameras and light meters (Please note: Wein Cells debuted in 1995 at a Photo Marketing Association show). These funny little batteries feature a zinc/air “green” composition that becomes activated by the removal of a tab from the battery.

This activation is accomplished via tiny holes that are sealed underneath the tab. Once the tab has been removed, oxygen enters the cell via the exposed holes and the ensuing chemical reaction results in the production of electricity. Unfortunately, this immediate energy production presents a unique problem–Wein Cells gradually decline even when not being used. Therefore, according to Wein Products estimates, you should expect about three months of life from newly installed cells.

You can prolong the life of your replacement batteries by removing them from your photographic equipment and re-installing the tab. Regardless, you should also be aware that a powder precipitate could form on the cells. Simply remove this residue and the Wein Cells should continue to produce 1.35V.

Fortunately, the use of Wein Cells couldn’t be simpler. In the case of that Luna-Pro, two Wein Cell Replacement PX625 & PX13 batteries, costing $8 each, are needed. Each battery has a small metallic tab on the base that must first be removed. An output of 1.35V will be produced by each battery. Wait approximately 30 minutes for the chemical reaction to stabilize, before installing the batteries inside the light meter. Voila! New life will be breathed into your vintage Luna-Pro enabling you to successfully meter the Zone System.

Enjoy.