Air Cell Batteries

[steve_levine]

<p>Are these the best solution to metering with old 1.3V, merc batt SLR's? Are these accurate? Do I have to play with ISO numbers to adjust or compensate? Is the compensation linear? Is there any downside or general annoyances in their use? Or do they work as if a 1.3V merc batt were aboard, and I'll be able to see the 1960's out my viewfinder?</p>

<p>Slightly off topic: Meters often die with age. But do they usually die completely, or they die slow and give bad readings on their way out? I've carried a tiny pocketsized (Sekonic) meter for years when I shoot my old cameras. But lately I'm thinking it might be fun to try the old TTL's. A 3 pack of the Air Cells is $10. So what's to lose? I'm just curious what I can expect.</p>

[sonny_chastant]

<p>I have found, as you said, meters do die. However, I use the Air Cells because they are easy and usually last longer than most experience....at least mine do. Naturally, if you can, you can have your camera calibrated for a readily available battery. Did that for my Konica Autoreflex T, and it work perfectly.</p>

[bob_sunley]

<p>Zinc air cells work just fine for me, I read somewhere that they don't with one particular camera that the current draw was too high to use them. Blue tab hearing aid batteries are a lot less expensive.<br>

I dunno about seeing the 1960's out of the viewfinder, that needs something a little more powerful that a small battery. :)</p>

 

[steve m smith]

<p>It depends on the meter circuit in your camera. If it has a bridge circuit which shows correct exposure when the meter needle is centred then the cell voltage does not matter that much. If correct exposure could be anywhere in the meter's travel, then it's not a bridge circuit and the voltage is more critical.</p>

<p>Another way to tell is the meter needle position with the meter switched off. If it rests in the middle of its range then it is a bridge circuit. If it goes to one end, it is not.</p>

 

<blockquote>

<p>I dunno about seeing the 1960's out of the viewfinder, that needs something a little more powerful that a small battery.</p>

</blockquote>

<p>You will need to install a flux capacitor for that.</p>

[Matthew Currie]

<p>I find in most cases hearing aid batteries make a good substitute. Whether or not you need to fiddle the ISO a bit may depend on the meter design and how many batteries it uses. If the meter uses a single battery, the difference in voltage between the zinc air and the mercury battery is such a small percentage that you probably won't notice it. If it's a two battery setup like the Konica SLR's it's a bit more significant. I find with my T3's that they want an offset of 2/3 stop to meter accurately.</p>

<p>Konicas can be recalibrated, I gather, but it's not entirely simple. ONe of these days I will resurrect the instructions I copied somewhere, and try it, but in the meantime, the zinc airs work. On the other hand, some others, such as the Nikon FTn head, are relatively easy to do, and all of mine now run on silver oxides.</p>

<p>On a single battery meter, it might be worth trying an alkaline, even though the voltage dropoff is a problem as they age. It will still probably last longer than a hearing aid battery, and the little alkaline cells are now available for nearly nothing at dollar stores and the like. I found, for example, that my Olympus 35RC is just enough out of factory adjustment to be right on the mark with a moderately fresh alkaline.</p>

[steve m smith]

<blockquote>

<p> If the meter uses a single battery, the difference in voltage between the zinc air and the mercury battery is such a small percentage that you probably won't notice it. If it's a two battery setup like the Konica SLR's it's a bit more significant.</p>

</blockquote>

<p>Actually, the voltage difference in percentage terms would be identical.</p>

[clay2]

<p>I'll stick my neck out on this one:<br /> After working with 2 Minolta SR-T101's and 2 Minolta Hi-Matic 7s's and Sekonic and Gossen light metres that<br /> also were designed for 1.35v mercury batteries, I've decided:<br /> 1/ Air-cells are fine and shorter lived.<br /> 2/ Schotky diodes and modern 1.5v batteries also work.<br /> 3/ Adjusting the ASA speed setting can work.<br /> 4/ Having metre re-calibrated can work.<br /> 5/ Since the death and burial of Kodachrome, the latitude in modern films will take care<br /> of the slight exposure errors when using silver oxide 1.5v batteries, so I have<br /> given up worrying about it.<br /> That's just my 2 cents worth, feel free to decide for yourselves.<br /> Best regards,<br /> /Clay</p>

[tomscott]

<p>I'm with you Bruce, not enough difference to worry about, at least with negative film, which is all I shoot anyway.</p>

[Matthew Currie]

<p>So maybe it isn't a percentage thing, but I have found that two-battery meters seem to be further off when the wrong cells are used. An unadjusted Nikon F with silver oxides or alkalines will be at least a full stop off, probably more like two. A Konica T3 will be off by two or three, enough to make compensation difficult with fast film, impossible with slow. But most of the singe-cell rangefinders I've tried were pretty close to correct without compensation.</p>

[astral]

<p>It might be the 21st century 'out there' but very often it's still the 1960s on <em>my </em>side of the camera!</p>

<p>I've recently been fittling zinc-air and silver oxice batteries in a whole variety of cameras and to be sure there are some incompatibilities, not least getting a good fit. As there is a lot of contradictory information on the web I have started making a list of compatible batteries and cameras, but it is limited to the gear that I own and progress is slow.</p>

<p>Spotmatics I & II and Miranda Sensomats are ok with silver oxides, but not Nikkormat FT and FTn: I haven't tried a zinc-air in a 'mercurial' Nikkormat yet. I am testing a Canon FTB with a zinc-air battery in a small home-made alumin(i)um 'cradle' and it seems fine: however, I don't think it can reliably handle a silver oxide.</p>

<p>Preliminary tests with silver oxide and zinc-air batteries on a Canonet QL17, Olympus 35SP suggest that they may be ok, but I haven't yet explored the full meter range.</p>

 

[w._keith_griffith]

<p>I've used Air cells in my Ftn, and finally needed a cleaning anyway, so I had it converted to use silver oxide. Just a matter of adding a diode and recalibrating.</p>

<p>Really happy with the conversion. Air cells didn't last long enough for me to think it was worth the effort. I usually ended up using a hand held meter.</p>