Silver Oxide batteries for Leica M5

Steinberg2010

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I have a Leica M5 which I know has been adjusted for Silver Oxide batteries, but I'm not sure where/what I'm looking for - does anyone have the model number as to what I should order?

Thanks,

~S
 
I'd also recommend springing for Silver Oxide rather than the alkaline equivalent (PX625a), which have a poor discharge curve, the original reason behind mercury batteries in light meters. However, Sherry Krauter, who did the recalibration on mine, specifically recommended Varta 625U alkaline to me. I'm guessing its not as much of an issue in practice, and when I've used them I take them out and test with a multimeter every so often.

Either way, order online or just make sure they're fresh. My local Ace Hardware sells 625s whose best-by date is back in 2015.
 
My newly acquired M5 has a Varta V625U and I have no idea if the voltage has been adjusted in the camera. But I do know that on replacing them with a Wien cell the resulting meter reading on the same subject produced a quicker exposure, either that or my brain is scrambled. Results from the test roll tomorrow.
 
My newly acquired M5 has a Varta V625U and I have no idea if the voltage has been adjusted in the camera. But I do know that on replacing them with a Wien cell the resulting meter reading on the same subject produced a quicker exposure, either that or my brain is scrambled. Results from the test roll tomorrow.

I'm not savvy with electronics, but I wonder if there's a way to find out whether or not the voltage has been adjusted, perhaps using a multi-meter or similar device?
 
The Wein cells are very quickly exhausted. For the M5 it is best to use an MR 9 adapter and a Duracell 385/301 battery. Years of enjoyment.


Erik.

Yes, I agree that for cameras whose voltage hasn't already been adjusted for modern batteries, the MR-9 adapter is probably the best way to go. I have one of them for that exact purpose!
 
I'm not savvy with electronics, but I wonder if there's a way to find out whether or not the voltage has been adjusted, perhaps using a multi-meter or similar device?

I'm not savvy but I do have a multimeter and a friend who is, so any ideas from anyone gratefully received. The M5 was such a pleasure to use today I'd really love to ensure it's metering consistently.
 
I suppose one could pretty easily determine if it's re-calibrated just by checking against a known-good meter or other camera with a gray (or any other color) card. If I'm remembering correctly (and my brain is scrambled too, from trying to perfect DSLR scanning this afternoon), a new battery in an uncalibrated meter will read high, i.e. shorter exposure. Someone correct me if I'm wrong.

But regardless, if it isn't set up for the higher voltage, it'll be a stop or two off from your control sample. When I thought I was going crazy trying to remember if mine was or not, I metered off the refrigerator and compared with the spot meter in my X100.
 
Pleasingly, every single frame of my M5 reel has come out exquisitely well, as I aimed off a half stop from the meter, and more in obviously very low light. Kodak Tmax400 does have a lot of latitude at 400, so part of it might be that, but it's still a result. Add in no shake at all on any photos at 1/15th and the M5 has really excelled. Its only flaw is an accessory shoe that is offset from the lens to the right, and with a 15mm Voigtlander superwide I can see the symmetry being out - a small crop is all that is needed to solve that though!

I think I've found my perfect rangefinder.
 
We're talking about a tiny difference in voltages. I never did nuthin. Always just put 1.5V batteries into anything that called for 1.35, mercury or otherwise, and never saw a nickle's bit of difference in exposure.

Be aware that an alkaline battery has a gradual voltage drop off, which means if you don't ck the voltage now and then the exposures will probably be off. The rechargable batteries will hold a steady voltage for a long time, then suddenly the performance drops off. Considerably. Or more accurately, the resistance will decline even though the voltage still looks pretty good, and it's the resistance that causes the battery to give you issues if you want accuracy.

A sound investment is one of those red multi meters you can get from Harbor Freight at the $5 price. If you get their fliers, you can often pick up so much free stuff when you go there it almost makes the meter free.

I cribbed the following from Green Batteries. Com. There, they got their plug. I knew all this, but they do a better job of explaining it. Even though they're talking about batteries in digital cameras, the physics are the same. With digital cameras, which require a lot more power, what happens is that the rechargeable alkaline battery will perform great right up to the point where the camera suddenly refuses to work.

"Why do my alkaline batteries run down so quickly when used in a digital camera (or other electronic device)?

Alkaline batteries were not designed to meet the very high power demands of today's electronic devices. Alkaline batteries have a high rated capacity, but they can only deliver their full capacity if the power is used slowly. Electronic devices such as digital cameras place a high power drain on batteries, so it is much better to use rechargeable NiMH or NiCd batteries for these type of devices. Lithium ion rechargeable camera batteries also work well in high drain applications like digital cameras but can be more expensive."
 
Common, relatively cheap SR44s have about the right thickness and just require some cardboard or an O-ring around the circumference to remain properly seated in a battery chamber made for the 625 type batteries. No need for anything more exotic.
For the same reason, I see no need to buy expensive Wein cells for cameras that have not been converted and don't work well with silver oxides. Cheap hearing aid batteries fit well enough with some cardboard.
 
Pleasingly, every single frame of my M5 reel has come out exquisitely well, as I aimed off a half stop from the meter, and more in obviously very low light. Kodak Tmax400 does have a lot of latitude at 400, so part of it might be that, but it's still a result. Add in no shake at all on any photos at 1/15th and the M5 has really excelled. Its only flaw is an accessory shoe that is offset from the lens to the right, and with a 15mm Voigtlander superwide I can see the symmetry being out - a small crop is all that is needed to solve that though!

I think I've found my perfect rangefinder.

One of my favorite features of the M5 is its spot meter, which allows you to meter smaller areas of a scene. I find it really useful in difficult lighting conditions.

The other favorite thing about the M5 is the feel of its shutter release - the best of any camera I have. It has even resistance through its entire travel distance, and allows you to very slowly depress the shutter. Even after the shutter is tripped, the resistance is the same. I think it contributes greatly to being able to get steady hand-held shots at very low shutter speeds like 1/15 or even 1/8. With other cameras, when you trip the shutter, the release suddenly bottoms out with no resistance to the end of its travel.
 
We're talking about a tiny difference in voltages. I never did nuthin. Always just put 1.5V batteries into anything that called for 1.35, mercury or otherwise, and never saw a nickle's bit of difference in exposure.

But doesn't a small difference in voltage amount to a not insignificant difference in exposure? As I understand, that may be at least one stop difference, and possibly more if you're using a dying alkaline battery where the voltage has fallen off a shelf.

Maybe you don't notice a nickel's bit of difference, but since I've invested quite a few nickels in my gear, I like to ensure that I have accuracy and consistency in one of the most fundamental aspects of capture - exposure. Plus I'd like to save film's latitude for exposure errors for user error (numbskull that I am), rather than equipment error. 😉
 
One of my favorite features of the M5 is its spot meter, which allows you to meter smaller areas of a scene. I find it really useful in difficult lighting conditions.

The other favorite thing about the M5 is the feel of its shutter release - the best of any camera I have. It has even resistance through its entire travel distance, and allows you to very slowly depress the shutter. Even after the shutter is tripped, the resistance is the same. I think it contributes greatly to being able to get steady hand-held shots at very low shutter speeds like 1/15 or even 1/8. With other cameras, when you trip the shutter, the release suddenly bottoms out with no resistance to the end of its travel.

Funny that - I was shooting it with my M3 and I noticed the difference - to start with different always induces a certain diffidence, especially as the M3 is no slouch in the shutter department. But I really think that as a camera to use the M5 wins. Which is a shame in some ways, but that meter swings it!
 

The Wein cell batteries provide 1.35v, which would work for non-adjusted meters. However, I believe the OP knows that their M5 has been adjusted for 1.5v silver oxide batteries. In their case, the Wein cell wouldn't work properly.

I think there are two issues for older cameras that take the PX625/PX13 mercury batteries. One is obviously the voltage, but the other is the shape of the battery. Modern button cell SR44 batteries won't fit properly in the battery chamber of the M5 because the old PX625/PX13 batteries also have a different shape and diameter. If you can't find a direct silver oxide battery S625PX replacement, one solution is to make a shim out of O-ring or something similar. Rick Oleson has one such solution:
http://rick_oleson.tripod.com/index-111.html
 
I thought it might be something to check out.

I own a Minolta camera and they work fine.

At any rate, if the M5 has been adjusted, so be it.

Here is some info to help:

https://schneidan.com/2015/05/19/the-trouble-with-mercury-batteries-and-what-to-do/

Yes, that article is a good resource. Here's the kicker for me, as far as just dropping in 1.5v batteries goes:

Increased voltage produces increased current at the output of the CdS cell, but the photoresistor’s output curve is non-linear — it’s logarithmic... Put simply: the less light the meter sees, the more similar the readings will be for two different input voltages. Hence using a 1.55-volt silver oxide battery will be close to accurate — maybe underexposed by a third of a stop or less — in low light, but potentially wildly inaccurate in bright light. By wildly I mean it could read several stops underexposed, depending on the light and the sensitivity of the CdS cell.

For those of us who spend many hundreds and thousands of dollars on the best lenses and equipment, leaving that much exposure difference to chance doesn't make much sense, at least to me.
 
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