Selenium meter overexposing in bright light

[dmitrizzle]

I’ve got a selenium meter on my Vitessa that works quite well in the shadows, however, everything brighter that sunny 5.6 gets overexposed readings.

Has anyone had that happen? Would love to hear your recommendations.

Thank you!

 

[Bill Clark]

I have a selenium hand held light meter, Sekonic L-158. Years ago I was told to keep it in the case when not in use that was included with it as constant exposure to light with the selenium cell gradually degrades it resulting in inaccurate readings.

Information to help:

https://www.photrio.com/forum/threads/how-long-do-selenium-photocells-last.31718/

http://www.largeformatphotography.info/forum/archive/index.php/t-83588.html

Truth be known, I have thought that it is like pushing water uphill to get everything perfect or near perfect with photography exposure. With film there are numerous variables, from the light meter, to the camera shutter to the batch of film used, to the many variables in the darkroom.

With digital, I find not as many variables but still quite a few.

Wih negative film I leaned to slightly over exposure, with slide slightly under exposure.

Digital I treated the same as slide film. I use the histogram and when I see the right wall getting touched I know I’m getting into the danger zone of over exposure. I also capture only using RAW as that gives me a file with more information to correct when I need to.

One of the most serious sins, at least it is to me, is when I see photographs that don’t have the proper balance of light with the foreground, middle and background. Blown out or very dark sections of a photograph are a no-no for me. When I was in business, during client interviews, I would show them this and, usually, they didn’t notice this until I pointed it out to them. It made my job easier, getting them to sign a contract with me, as so much of this is around, especially today, as a reliance with so-called automatic cameras.

 

[Steve M.]

It's usually in low light that selenium meters are off. Every one I have owned that gave semi accurate readings outside gave wonky readings indoors. After a while I learned to compensate for that to a point, but it's a lot nicer when you get accurate readings in any light. As much as I love the concept of selenium meters, they are limited, and none of them can be trusted in low light. It's just the nature of their design. You might be better off using sunny 16 outside, but a handheld meter looks to be the answer. The one below is my favorite. Accurate enough in low light, cheap to buy, and dead reliable. They're so small and light you don't even notice it in a shirt pocket.

http://www.jollinger.com/photo/meters/meters/sekonic_l188.html

 

[BLKRCAT]

I think selenium meters are cool. But I would never use one seriously. Too unreliable.

 

[dmitrizzle]

Hmm that’s what I keep reading is that they tend to give up in low light. However, mine is fine indoors. So it could be me, high shutter speeds or the meter. I’ll check shutter speeds and double check exposure measurements against working meter tomorrow,. As for myself I tend to aim it at the shadows and the ground when measuring as per manual - maybe I should change that? Also, seeing that the meter is quite responsive and isn’t following the common failure pattern, could there anything else be happening?

I’m looking at the same roll of porta 160 developed and comparing indoors and outdoor shots. So it’s not the film or the lab.

Thank you for your input guys

 

[Sarcophilus Harrisii]

I’ve got a selenium meter on my Vitessa that works quite well in the shadows, however, everything brighter that sunny 5.6 gets overexposed readings.

Has anyone had that happen? Would love to hear your recommendations.

Thank you!

If the meter is suggesting a lower EV than is appropriate for bright conditions it suggests the cell is not generating enough output to deflect the galvanometer needle far enough. Possibly loss of continuity from the transparent conductive layer or compromised connections to the cell. There could be a number of causes. Voigtländer cells from the 1950s were some of the better quality and more durable ones in my experience. They will certainly fail sometimes, but even today, working examples can still be found. If the camera was mine, I would remove the top cover to investigate possible causes of excessive resistance. If you’re really lucky it might be some oxide on the wiring at the cell. But bear in mind it’s an almost seventy year old camera so there are no guarantees of success.

Also bear in mind as this is a metered Vitessa it will not be the earliest type of cover (you have not mentioned which model). Meaning the plunger knob most likely has to be unscrewed to get the cover off. It’s important not to damage the engaging lug for the film wind and cocking when the knob is unscrewed so take some care. Early Vitessas really were better in as much as the integral plunger knob would clear the cover opening, hence no need to unscrew it (nor was it possible to do so for that matter).
Cheers
Brett

 

[dmitrizzle]

If the meter is suggesting a lower EV than is appropriate for bright conditions it suggests the cell is not generating enough output to deflect the galvanometer needle far enough. Possibly loss of continuity from the transparent conductive layer or compromised connections to the cell. There could be a number of causes. Voigtländer cells from the 1950s were some of the better quality and more durable ones in my experience. They will certainly fail sometimes, but even today, working examples can still be found. If the camera was mine, I would remove the top cover to investigate possible causes of excessive resistance.
Cheers
Brett

Hi Brett it’s Vitessa L version 3. I’ve done some repairs on it, can take off the cover no problem. Though right now there’s film in it, so not until I finish shooting it... unless I get impatient.

 

[dmitrizzle]

Some context from the photos. This is Porta 160, which I shot at 200 on my Vitessa. Interestingly, when overexposed the hue tends to shift aggressively away from all reds - is that typical for this film?

Attached are two images, first of which worked out fine, and a couple which didn't - all on the same roll. One of the blown out images is all messed-up, another has high contrast where highlights have shifted hue (the stone is brown-ish grey in colour).

https://i.imgur.com/bMOj8fi.jpg

 

[johnnyrod]

A lot of my cameras with selenium cells will read a stop or maybe two over-exposed in bright light compared to low light, I think (crudely) that the old cells are just maxed out. To be honest with the old shutters which, even when working well, run around half the indicated speed, does mean overexposure.
I can't help you on Portra 160 but I have shot some 400 in 120 format and it doesn't seem to like overexposure, becoming washed out and losing contrast.
Finally, I don't think you said if you scanned negs or prints, or for that matter who did it. The duff colours in the last one could be poor auto adjustments perhaps? It does seme to have lost a hefty chunk of red alright.

 

[peterm1]

Selenium meters become less responsive and accurate over time and eventually they all die. This much is pretty well known in the classic photography community.

I wonder - if the above happens, such a meter would under-register ambient light on the meter, and would not the actual exposure taken on the film then be over exposed because you would be fooled into making the wrong settings on the camera because the meter is telling you there is less light than there actually is and you are applying these settings to the camera? Your specific experience suggests of course that the meter is "topping out" (i.e. less responsive as the light increases) and this may well be a feature of that phenomenon. Of course I wonder too if your old camera's shutter is still accurate. If running slow that would explain it too.