Do NOT put alkaline batteries in your OM-2n ...

Keith

The best camera is one that still works!
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... if you want your meter to be accurate!


There's been a couple of threads about batteries lately pointing to the inadequacies of alkalines in certain cameras ... in particular the LR44/A76 that fits a miriad of cameras and notably my OM-2n!

I put a fresh set of LR44's in the camera a few weeks ago and checked the meter and it was bang on ... two weeks later with almost zero use it was two thirds of a stop out ... I've just checked it again and it was a stop and a half out.

These alkalines lose their peak voltage very quickly and suffer a notable drop which dramatically changes the metering in the Oly ... but I can put these same partially discharged batteries in my Ikon and it's business as usual with no effect on the meter at all!

I read somewhere not to put anything but SR44's (silver oxide) in the OM-2n but figured alkalines should be fine provided you change them fairly regularly ... not really! :(

Silver oxides are a little harder to track down and they cost twice as much but I definitely won't be using anything else in the OM2n in future. I'd be interested to hear our resident OM guru, John Hermanson's opinion on this?
 
Silver oxides may cost twice as much, but those last more and better.
Well, I don't know how much does the OM-2 need, being more electronic; but the SR44 that came with my OM-1 the day I bought (Nov '08) it is still in the camera. The meter is spot on.

Interesting experience. Lesson learnt. I wonder how alkaline would behave in an OM-1 meter, being more simple. I won't try it, though.
 
I guess the batteries have different curves, but I think it has more to do with the design of the camera's electronics. My Fujica ST 901 uses alkaline batteries, and they last a year or so. Some cameras probably have circuitry that uses batteries more efficiently, either because of the capacitors used or the metering cell.

Hopefully someone who knows about such things can comment, as I may be all wet on this.
 
The OM2, 2sp and 4 were notoriously bad at power management, missing some kind of voltage control in their circuitry.

The batteries will drain even with the meter turned off and the shutter speed set to "B" or "manual 1/60".
I think that the situation was improved in the OM4T and OM3.

The 2 and 4 have such great metering systems that I find it well worth putting up with their foibles.
 
OM-1 and 2 meters use the voltage "as is" from battery. If the voltage drops, the meter reading changes.

Bessas and Ikon use digital circuits to measure light, so are more resistant to voltage changes.

OM-2sp, 3 and 4 including the Ti use digital light metering, so the light meter is resistant to slight voltage drop of the alkaline batteries, but the electronic shutter needs a lot of juice for operation. It draws high current and so the voltage drops more dramatically to levels where it's insufficient for the shutter operation. But this could happen also with electronic Bessa or Ikon.

Battery drain is a completely different thing all OMs are famous for. The cameras draw a very small amount fo current even when nothing operates, and (in case of the 2sp, 3, 3Ti, 4, 4Ti) even when set to manual speed or B. Especially the 2sp, 3 and 4 are famous for eating batteries. The 3Ti and 4Ti with improved circuits draw less current and the batteries last longer.
 
Keith,

You found out the hard way that the discharge curve of alkalines is quite steep. The silver cells have a very flat curve - more like the old mercury cells in fact.

This is why the SR44 is such a great boon in PX625 adapters - you get the right voltage and discharge curve :)

Now, if only I could find a good silver based solder, I could put my adapters back in production - irrelevant for your Oly, but great for a heap of 1970's classics!
 
I was amazed how hard they were to get locally. The local Kodak one hour has them ... but for $8.00 each! (choke)

I found an online battery specialist who had Maxells for $19.00 for a card of five ... here by post in two days! :)

I always suspected my OM-2 was over exposing a lot of the time ... good to find out why.
 
I guess I am lucky, SR44 batteries are common in Japan, they are even available at my local grocery store.

I never had an issue with the LR44 batteries in my OM4Ti, I got about 6 months of life out of them with regular use of the camera. On the other hand, they don't seem to last as long in my M6 TTL, I had to install a new set the other day (which is when I noticed that the grocery store had the SR44's).

My old OM1 uses the old mercury batteries, and I generally run Wein cells in it. Those last me a few months and work perfectly well. They are also relatively cheap.
 
As 2N production progressed, new USA product came from Japan packed with a pink sheet at the top of the box. First thing you saw when you opened it. It explained why only silver oxide 1.55V batteries and not alkaline or lithium cells. This does not involve OM-4T/Ti. Alkaline, lithium cells in original Om-3/4 will have very short lives. John
 
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