Minox B meter issues

[Minox]

A Minox B camera acquired recently has baffled me since I loaded the first film. The film setting is DIN, and it's a metric distance dial, lattice meter, in excellent condition.

However, the meter appears to be way too sensitive. I know this sounds weird, but it does measure at least 1 full stop above anything my meters show (checked with 3 different and calibrated meters, Lunasix 3/Nikon FM3A camera meter/recently refurbished cell Weston Master III). For instance, when every meter shows 1/500s, the B has a 1/1000s reading.

No idea why this is. Meter cell aside, could this be related to the film setting internals being damaged? Or perhaps the meter window has a small space that lets more light onto the cell? Could any of these explain why the light impacts the selenium cell in an unusual way? As said, I am really baffled.

The DIN has been set at 20, related to the 100 film I am using, and yes, the "100" red dot rule observed.

As selenium cells do not usually read low light indoors, this one does, and accurately so. It reads the correct light, on par with the Lunasix 3, which is unusual.

Anyone has any thoughts on this matter, please? Thank you !
Best,
JT

 

[Kino]

Could it be that this camera meter was "tuned" for accurate low light levels at the expense of higher levels?

Maybe you have a true spy camera optimized for copying documents under a dim flashlight!

 

[Minox]

I know customizing some Minox cameras for special purposes was a thing, and probably is, in some circles. I also know that Microtech USA used to modify some Minox EC for closeup focusing, and infrared photography.

But I do not know, and never heard of mechanical Minox cameras modified for special purposes. How could that be achieved in this particular case, I wonder?

However, I very much doubt this Minox has been modified

 

[Kino]

I know, it's a mystery. Usually the selenium cell decreases in sensitivity; not increases.

Might you cut a .30 ND filter to place before the meter? Seems a better problem to have a meter too sensitive than unresponsive!

 

[xkaes]

Exactly how and what are you metering for comparison?

Each meter has to be seeing the same thing at the same angle in the same way.

A grey card would be the best subject.

Do this in bright light and then in dimmer light.

If all else fails, and there is no different between HI & LOW light, just divide the ISO by 2 -- which is what I do anyway with my B&W Minox films.

 

[Minox]

Right, I haven't tried the grey card thing. Will do so, hopefully this will explain itself. Metering is from the same spot, same angle, same thing pointed at, and the light remains the same throughout the comparisons. Subjects are both objects in plain light, and normal shadows. Nothing extreme, nothing different from one metering to the other.

Thank you !

 

[xya]

I guess you followed the instructions for coupling the meter to the film speed. Just in case, I made a page for this camera, coupling is at the bottom of the page https://www.subcompactcam.com/8mm_minox_b.htm

If you are through the gray card calibrating, just note the difference to the real film speed and adjust the film speed setting of your camera.

 

[Minox]

Thank you for your input, appreciated !

 

[Minox]

The plot thickens. I checked today the B's meter by means of a grey card, against a fully working Lunasix 3. Conditions were all the same, light the same, distance and film settings the same. Thought to go towards the higher end of the sensitivity, as this made sense to me. No point in going lower, I believe.

The readings I got from the problematic B:

1) At 100 ASA (DIN 21), reading of the card gave me way over the speed of 1/1000 (like almost 2 stops over), when Lunasix read 1/500.

2) I changed the DIN at 23, same reading gave me just a notch over 1/1000, perhaps 1/2 stop.

3) I changed the DIN to 26, reading gave me 1/700.

4) At DIN 26, sliding the ND filter over the lens, I had the right meter reading.

I am still not entirely sure on what goes on here. I wonder if there is something here I'm badly missing.

PS - yes, the film setting was observed, including the (re)setting of the red dot at 100.

 

[Minox]

I believe I just had enough of this little rascal. It will be taking the long road to MS Hobbies for repair, which appears to be a case of need. And it will not go alone, mind; another 3 or 4 Minox various models are awaiting despatch. It shall be travel in good company, as it were.

Thank you all !