Selenium based light meters

NGH

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Hi
I have seen in various places that the selenium cells in meters deteriorate the more they are exposed to light and that in order to keep them working you should keep them covered when not in use.

I have also seen in a few places that the above is a complete myth and that exposure has no affect on the cells at all.

Does anyone know for sure?
 

vintagesnaps

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Could be, I have old cameras that have a little door that flips down over the meter compartment when not in use, so I suppose that's to protect the meter. I've gotten old cameras with selenium meters that were still working.
 
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tirediron

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What I can say with certainty is that every selenium meter that I've ever had has grown less and less reliable as it got older, and they all eventually just stopped working.
 

dxqcanada

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Discussions about this topic point to atmospheric/manufacturing influences that causes deterioration of the material ... not the continuous excitation of electrons by light. I tend to agree with that.
 

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I was always told that Continued exposure to light eventually weakens and deadens the selenium cell. I have had two working selenium meters die on me . This was back in the 1970s and they were both about 20 some years old.

I do not think that selenium meters are all that reliable. But this is based upon having two cameras with built-in selenium in meters and ownership of 3 handheld selenium meters.
 
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webestang64

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Selenium is a non-metallic element which sits at number 34 on the Periodic Table. In its vitreous form the material acts as a semiconductor, which is both photoconductive and photovoltaic. This last property was initially harnessed in 1883 with the development of the first practical photovoltaic cell. Although these cells put out very little power, they became the basis of the first electronic light meters, and gave photographers a simple and accurate tool for determining correct exposure values. Because the selenium produces a current proportional to the light that's shining on it, the meters don't need batteries. The meter circuits are very simple and dependable, typically consisting of only the selenium cell, an ammeter, and some resistors. These advantages made selenium cell meters popular for many decades.
There is a persistent myth passed around on the web that selenium cells "wear out" with age. Needless to say, any electromechanical device is liable to have problems after 50 years. There can be various reasons why a selenium cell meter does not work, and a defective cell is only one of these. The cells do not invariably deplete with age, like a battery. But if the cell is left out in the light in a humid environment, the internal current will corrode the cell and increase the internal resistance. This reduces the electric output of the cell. If this has occurred, the only solution is to replace the cell.
 
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NGH

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Selenium is a non-metallic element which sits at number 34 on the Periodic Table. In its vitreous form the material acts as a semiconductor, which is both photoconductive and photovoltaic. This last property was initially harnessed in 1883 with the development of the first practical photovoltaic cell. Although these cells put out very little power, they became the basis of the first electronic light meters, and gave photographers a simple and accurate tool for determining correct exposure values. Because the selenium produces a current proportional to the light that's shining on it, the meters don't need batteries. The meter circuits are very simple and dependable, typically consisting of only the selenium cell, an ammeter, and some resistors. These advantages made selenium cell meters popular for many decades.
There is a persistent myth passed around on the web that selenium cells "wear out" with age. Needless to say, any electromechanical device is liable to have problems after 50 years. There can be various reasons why a selenium cell meter does not work, and a defective cell is only one of these. The cells do not invariably deplete with age, like a battery. But if the cell is left out in the light in a humid environment, the internal current will corrode the cell and increase the internal resistance. This reduces the electric output of the cell. If this has occurred, the only solution is to replace the cell.
Selenium is a non-metallic element which sits at number 34 on the Periodic Table. In its vitreous form the material acts as a semiconductor, which is both photoconductive and photovoltaic. This last property was initially harnessed in 1883 with the development of the first practical photovoltaic cell. Although these cells put out very little power, they became the basis of the first electronic light meters, and gave photographers a simple and accurate tool for determining correct exposure values. Because the selenium produces a current proportional to the light that's shining on it, the meters don't need batteries. The meter circuits are very simple and dependable, typically consisting of only the selenium cell, an ammeter, and some resistors. These advantages made selenium cell meters popular for many decades.
There is a persistent myth passed around on the web that selenium cells "wear out" with age. Needless to say, any electromechanical device is liable to have problems after 50 years. There can be various reasons why a selenium cell meter does not work, and a defective cell is only one of these. The cells do not invariably deplete with age, like a battery. But if the cell is left out in the light in a humid environment, the internal current will corrode the cell and increase the internal resistance. This reduces the electric output of the cell. If this has occurred, the only solution is to replace the cell.
Thanks that is extremely helpful.
 

cgw

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Selenium is a non-metallic element which sits at number 34 on the Periodic Table. In its vitreous form the material acts as a semiconductor, which is both photoconductive and photovoltaic. This last property was initially harnessed in 1883 with the development of the first practical photovoltaic cell. Although these cells put out very little power, they became the basis of the first electronic light meters, and gave photographers a simple and accurate tool for determining correct exposure values. Because the selenium produces a current proportional to the light that's shining on it, the meters don't need batteries. The meter circuits are very simple and dependable, typically consisting of only the selenium cell, an ammeter, and some resistors. These advantages made selenium cell meters popular for many decades.
There is a persistent myth passed around on the web that selenium cells "wear out" with age. Needless to say, any electromechanical device is liable to have problems after 50 years. There can be various reasons why a selenium cell meter does not work, and a defective cell is only one of these. The cells do not invariably deplete with age, like a battery. But if the cell is left out in the light in a humid environment, the internal current will corrode the cell and increase the internal resistance. This reduces the electric output of the cell. If this has occurred, the only solution is to replace the cell.

Gospel. I'd only add this sound and informed advice above should dissuade anyone from buying a relic meter. Something like a Sekonic Studio Deluxe--a modern version of the ancient Norwood Director--is a better bet. Just be aware that a baked-in limitation of the these meters is a very limited low-light capability.
 

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Some Selenium cells deteriorate more than others, the Weston meters are quite bad in this respect both mine are now useless. An easy test is point the meter at a bright light source and see if the needle moves to the maximum, mine get to abou half and three quarters of the max.

My pre-WWII Avo meter still works perfectly and is over 80 years old, so compare that to the now useless Weston Euromaster that's just over 35 years old. I have two old reliable Leningrad 4 meters and they work fine so it's a bit hit & miss some last well compared to others.

Ian
 

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It comes down to the QUALITY of the selenium meter cell itself.

I ended up at a rummage sale getting a vitomatic 2 with a fully functioning light meter. Kept the thing stored in an old lunchbox when I wasn't physically shooting film with it. In 5 months it went from working to NOT working.

Its a strange malfunction, natural light can make the needle merely bounce about, while holding it a foot from a cree led flashlight makes it show its in low light..
 

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About 1 year ago I found a working selenium meter, a 1953 GE model, which was exactly like the one I started photography with in 1974. I found it in a pawnshop junk bin, and paid $2 for it.
 
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compur

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Selenium is a non-metallic element which sits at number 34 on the Periodic Table. In its vitreous form the material acts as a semiconductor, which is both photoconductive and photovoltaic. This last property was initially harnessed in 1883 with the development of the first practical photovoltaic cell. Although these cells put out very little power, they became the basis of the first electronic light meters, and gave photographers a simple and accurate tool for determining correct exposure values. Because the selenium produces a current proportional to the light that's shining on it, the meters don't need batteries. The meter circuits are very simple and dependable, typically consisting of only the selenium cell, an ammeter, and some resistors. These advantages made selenium cell meters popular for many decades.
There is a persistent myth passed around on the web that selenium cells "wear out" with age. Needless to say, any electromechanical device is liable to have problems after 50 years. There can be various reasons why a selenium cell meter does not work, and a defective cell is only one of these. The cells do not invariably deplete with age, like a battery. But if the cell is left out in the light in a humid environment, the internal current will corrode the cell and increase the internal resistance. This reduces the electric output of the cell. If this has occurred, the only solution is to replace the cell.

Are you the owner of the website that this quote was taken from? (Just curious)
 

webestang64

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Are you the owner of the website that this quote was taken from? (Just curious)

No.....I hope I did nothing wrong. Guess I should have noted in my post "found on internet". I've used it a few times in the past, I've had customers at the store I work at ask me about these type meters.
 

compur

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I was just wondering if that was your site.
 

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