MR-9 Adapter Question

[wastelanded]

Hello All,

I bought one of the above-mentioned adapters, that knocks the voltage of a 357 battery down to 1.35v in place of the old PX-625 mercury battery.

When I use the adapter in my Hi-matic 9, it works perfectly. But in my Olympus 35 DC, strange things happen. The electronic shutter will fire, but the needle in the viewfinder stays swung to the right of the scale. Any thoughts on why this happens?

Forgive me of this has been covered before: I tried searching but came up empty handed.

 

[BrianShaw]

Some "odd" but meaningless artifacts happen.

On my Gossen meter the neeedle goes to the extreme right side of the "okay" zone during battery check. It's still within the zone, just at an extreme rather than the center. And the meter is very accurate.

On my (former) Canonet with the adapter, the shutter and meter worked perfectly but the battery check light would not illuminate. A known situation but had no affect on the real functionality.

But I have no idea WHY.

 

[wastelanded]

Ah yes, I forgot to mention that the battery check light does not light either. It's weird, the shutter is obviously getting power but no meter.

This was my grandfather's camera, I'd like to use it. I guess I could use a silver oxide 625 and adjust the meter accordingly.

 

[Dan Fromm]

Try using a 675 zinc-air hearing aid battery. See my Horseman meter article ([URL]http://www.galerie-photo.com/horseman-4x5-exposure-meter.html) [/URL]for a fuller explanation of alternatives to mercury cells.

 

[Gerald C Koch]

When changing to another type of battery there are three considerations.

1. The output voltage of the cell must match that of the original. If not the meter will gives false results.
2. The discharge curve should have a wide horizontal portion so that the voltage remains constant as the cell is used.
3. The output amperage must be sufficient to power the meter.

Failure to observe all three conditions will cause problems.