Leicameter 2 Repair with Silicon Photo Cell

As I mentioned in an earlier post, the used 1960 Leicameter 2 light meter that I purchased on eBay required a new selenium cell. There were no selenium cells to be found online. The only source, located in the UK was out of business. I read online about an alternative to selenium by using silicon based cells. These are the same cells used in calculators.The existing selenium cell is 25mm by 10mm. I was able to find a silicon cell measuring 22mm by 7mm.
Old Selenium Cell from the Front

Rear of Selenium Cell (notice crack)

I was able to find a silicon cell measuring 22mm by 7mm.

New Silicon Solar Cell

The other item needed is a resistor. Not knowing what the output of the original selenium cell is, I purchased a 100K OHM adjustable resistor.
New 100K OHM Adjustable Resistor

I soldered wires onto the new silicon solar cell. Next, on the + side I soldered inline the resistor. To take full advantage of the adjustability of the resistor, you must connect between terminal 1 and 2 (middle).

Now it is time to run some tests. I touched the terminals connected to the electromagnet with the wires from the new solar cell and voila the needle moved. I adjusted the resistor until the needle matched the reading of another lightmeter that I own. I proceeded to remove the old cell and resistor and replaced with the new solar cell. To take up some extra space I used a small piece of painted balsa wood. After reassembling I checked against my other meter and adjusted the ASA/ISO gauge to match.
Completed Leicameter 2

How it Looks on the Camera

For more information on the Leicameter click here.

The Leica Meter 2

A light meter is really useful with an old camera like the Leica IIIa. Leika made what they called the LEICAMETER. They had two universal meters that fit on the older Leicas and then they came out with the LEICAMETERS for the LEICA M Series cameras that actually coupled to the shutter-speed dials.
I ordered one on eBay knowing that it might not work but was hoping that it could be repaired. Unfortunately, it could not be repaired. I opened it up and it was very clean with no corrosion on the terminals. I even took the Selenium cell out. I wrote to the only person that I could find online that repairs old light meters. It is a place called Quality Light Metric. He wrote back saying the cells are no longer available. There was a place in the UK that was cutting them, but they went out of business.
Here is what it looks like on the camera


Here is what it looks like apart.

I have read that a calculator solar cell might work in the place of the selenium cell. A project for another day.