Leica M5: Using 1.5v silver oxide batteries

hipsterdufus

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I was the lucky purchaser of a very nice M5. However, it does not appear to be calibrated for 1.5v batteries. It seems to be reading ~ 1-2 stops over depending on the situation. Is this typical for an uncalibrated M5? Should I get a 1.4v zinc battery to try out? I don't have any proper batteries for it at the moment... Just curious, because I may be reselling. Thanks.
 
I cheat with old cameras that use the 1.3v batteries. The higher voltage makes the meter more sensitive causing underexposure by about a 1.5 stops. Simple set the iso 1.5 stop lower on the camer than what you wish to expose at. It's not perfect but does work.
 
I cheat with old cameras that use the 1.3v batteries. The higher voltage makes the meter more sensitive causing underexposure by about a 1.5 stops. Simple set the iso 1.5 stop lower on the camer than what you wish to expose at. It's not perfect but does work.

That answers my question. That's kind of what I figured, but I wanted to confirm with other users who have used 1.5v batteries. Might as well get some other folks chiming in to confirm. Anyone else?
 
I'm sure Sherry or DAG would be able to fix this.

Oh, I'm sure they could. $200-$300 later... This is more just for my own info, as I'm not sure I'm keeping the camera. I may be listing it on RFF and want to be able to give an accurate description.
 
I would not recommend a conversion to alkaline 625, well unless someone installs the proper diode. Better by far (than the alkaline), I think, is to use the Criscam adapter with silver oxide, bringing it down to the original 1.35 volts

With the alkaline you lose linearity—the meter can be accurate in daylight, but in low light in evening or indoors call for an extra stop of exposure. As the battery changes so does your meter sensitivity. And these conversions are very sensitive to the type of battery, Varta versus Energizer can account for 1/2 stop difference.

So, for me, the Criscam adapter is totally worth it to have a linear, dead accurate meter (or perhaps the proper diode with a silver oxide).
 
I cheat with old cameras that use the 1.3v batteries. The higher voltage makes the meter more sensitive causing underexposure by about a 1.5 stops. Simple set the iso 1.5 stop lower on the camer than what you wish to expose at. It's not perfect but does work.

It's not that straightforward. You need to find a battery that matches PX-625's discharge curve. Otherwise, you may have to adjust the compensation value according to how much battery life left. If you are mainly shooting negs, you won't have much trouble though.
 
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Oh, I'm sure they could. $200-$300 later... This is more just for my own info, as I'm not sure I'm keeping the camera. I may be listing it on RFF and want to be able to give an accurate description.

With Sherry, it'll be about $322 later... and you'll keep the camera. Believe me, I speak from experience. ;)
 
OK, here's what I know...

Wein cell works. As confirmed by using them in my Gossen Luna-Pro. When the first one dies, save it. What you have is a #675 zinc-air battery in a washer to make the correct outer diameter that matches the 6325 battery. Still with me? Place the dead Wein cell in a 1/2" hex. socket. Use a block of wood and a hammer. Tap the battery out. It's a one way fit. If it doesn't come out with a good whack, turn the battery over. Repeat. You should end up with a washer looking thingie and the battery in the socket. Buy cheap cheap hearing aid #675 batteries and press them in the washer. Enjoy.
Or. Buy the silver oxide batteries. They work more like the old mercury batteries. Avoid alkaline batteries.
Wayne
Hording a stash of old batteries. Bigfoot loves them.
 
Crisis Adapter+1.5 volt silver oxide. It worked in mine but the cover did not go down fully. It does not work in all cameras for various reasons, but does work in the M5. What happens is exposures are correct at high or low light, but not the reverse. I forget the correct way.

1.3 volt alkaline works if you keep it very very fresh. Meter circuit does not compensate for 1.2 volts giving false exposure.
Original mercury cell held 1.3 volts almost until they died.

1.35 hearing aid battery with O ring spacer to keep it from flopping around.

Wein cell. Same as a large hearing aid battery, but both have a short life. Secret is to recover the holes after the shoot. Deterioration stops then.

At first opportunity, have the meter circuit modified.
 
For the record (if not for the OP), if the M5 is modified to accept a Varta 625U alkaline the meter will be perfectly liner from very dim to very bright light—dead accurate. As the battery drains over much use, the meter will stay linear in daylight, but in very low light ask for an extra stop of exposure.
The Varta battery seems to work much better than the Energizer, though they register similarly on my voltage meter.
 
I had a similar problem with my Rollei 35 and the solution is simple. Get the new generation MRB625 replacement Wein cell, the one with only two air holes. Once activated, they are claimed to last about a year in the camera, far better than the older generation of Wein cells that lasted a few months. They are fairly cheap online at about $1.50 each, beating the C.R.I.S. adapters costing many times more. I tried it on my Rollei and metering matches a mercury cell I had to compare it with. These cell come closest to giving the even discharge of mecury cell.
 
Ronald M--You mentioned that when using the C.R.I.S. adapter the cover on the battery compartment would not go down fully. Originally it was recommended to use the S76 battery (same as 357) with the adapter. This adapter/battery combination was thicker than the 625 battery you were trying to replace. However, the currently recommended battery is the 386. It is thinner than the S76/357 and fits cameras same as the original 625.
 
Oh, I'm sure they could. $200-$300 later... This is more just for my own info, as I'm not sure I'm keeping the camera. I may be listing it on RFF and want to be able to give an accurate description.
FWIW, I sent my M5 to Sherry to have the rangefinder adjusted. That cost $150, but she also re-calibrated the meter (which was about 1 stop off) for no additional charge, and even threw in a new mercury battery! If the meter is all that is needed, it may cost even less.

The 1.5 vs 1.35v difference really shouldn't cause the meter to be 1-2 stops off alone. It probably needs to be recalibrated regardless.
 
I was the lucky purchaser of a very nice M5. However, it does not appear to be calibrated for 1.5v batteries. It seems to be reading ~ 1-2 stops over depending on the situation. Is this typical for an uncalibrated M5? Should I get a 1.4v zinc battery to try out? I don't have any proper batteries for it at the moment... Just curious, because I may be reselling. Thanks.

I have M5, and I use MR-9 adaptor which basically step down SR-43 1.5 volts to 1.35 volts. This battery adaptor is not expensive around 20-30 dollars, and you only need to buy SR-43 battery (easy to find and cheap). I don't think it's good to use 1.5v in 1.35v M5.

Here's a sample link for MR-9 adaptor http://www.kanto-cs.co.jp/english/adapter/adapter_en.html

Rgrds,

Beta
 
I have several CRIS adapters and a Mercury battery still good, and have compared lightreadings in my M5 at high, medium, and low light levels. The CRIS adapter really does work 100% as well as a Mercury Battery, and is not -that- expensive. Wein cells work, but are expensive and very short-lived, I have found. The CRIS is a better solution, for me.
 
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