JeremyLangford said:
So he will recalibrate the meter for me or whatever to make a 1.5v battery work?
Would you reccomend him over John Titterington?
http://www.geocities.com/~titterington/camera-repair/index.html
John Titterington did a great job of cleaning out my entire camera and fixing my self-timer.
From his website: "The new mercury free 1.35 volt batteries do not work well in the Minolta SRTs. Their shape causes them not to make good contact with the battery cap. We suggest using a 1.5 volt 625A battery and having the metering system recalibrated to this new voltage."
This sounds good, at first glance, but if you think about what he is actually saying for more than a moment, it is wrong on so many levels I hardly know where to begin. The problem and the solution are both misstated, and quite badly.
The problem is not that the new batteries don't fit. They do, and he must be talking about C.R.I.S. MR-9 adapters instead. Oh, wait a minute, most of them are built out of the shells of used 625A batteries. The "problem" must be that you have them turned the wrong way, so the slot in the side is where the battery contact in the camera is trying to hit. He can't be talking about Wein cells, because those are exactly the same size as the original mercury batteries (unless he is just plain lying; I wonder if that could be it).
The actual problem is that the cameras were designed to run on a really rock steady 1.4 to 1.35 volts. Mercury batteries had a negligable voltage curve (1.4 to 1.35 volts over their entire lives) and were so steady that hardly anyone but Yashica (and only a few kinds of Yashicas at that) saw fit to put voltage regulation circuitry into the cameras that used them. The #625A alkaline cells he recommends start off at 1.5 volts (roughly), but they have a steep voltage curve, steadily losing voltage over their entire lifespan. You get about a week or two, somewhere toward the beginning, when they are between 1.4 and 1.35 volts and will work right, but before and after that the voltage is either going to be too high or too low. Regardless of how your light meter is calibrated, they won't work right with it, because the voltage level is not constant. There are even a few cameras that can be damaged by the higher initial voltage from a 1.5 volt alkaline cell. You can't adjust for it either, because your meter's response will be non-linear according to the light level if the voltage is either too high or too low. If this is not the case, you have a Yashica, it is a G-series, it never used #PX625 mercury batteries and it will run on anything between 4 and 6 volts.
The solution to this problem? Well, there are several. Fundamental to all of the ones that work is that you have
GOT to start with a battery that has a steady voltage curve. This pretty much means mercury batteries, silver oxide batteries or zinc/air batteries. Then you have to get a voltage out of it that is between 1.35 and 1.4 volts.
Solution #1:
Just get a new mercury battery. They are still being made overseas, in several third world countries. Getting them into the country is a problem, but a few do turn up here from time to time.
Solution #2:
(the one that the C.R.I.S. adapters use): Modify a 1.5 volt silver oxide battery with a schottky diode in order to get 1.4 - 1.35 volts. Silver oxide batteries, unlike alkaline batteries, produce a fairly level voltage curve. It isn't quite as level as a mercury battery's, but close enough that it isn't going to cause much in the way of problems. However, one problem is going to be noticable: If you need to draw a lot of current, it won't be able to keep up if you are using a small battery. The most commonly noticable effect of this is that the battery check light on a Canonet won't work well with a C.R.I.S. MR9 adapter (if at all).
Solution #3:
Instead of modifying the battery, modify the
camera to use a 1.5 volt silver oxide battery. You can either recalibrate the meter (on some cameras) or solder a schottky diode in series with the battery. This will
NOT work with a #625A (alkaline) battery. The Varta brand #625A batteries only work well in cameras with bridge circuitry, like a few Yashicas. You need a #675 or #357
silver oxide battery, adapted for size (or you can get a new battery holder and solder it in).
Solution #4:
The Wein Cell. Wein makes 1.4 volt zinc/air batteries in #625 size. They are no different from other zinc/air batteries except that they are the right size and they only have 2 holes in them to admit air instead of the more normal 4. Basically, they are #675 zinc/air batteries with two holes missing and wearing collars. They also cost more than normal zinc/air cells -- a lot more. This leads us to ...
Solution #5:
Use a smaller, normal, inexpensive 1.4 volt zinc/air hearing aid battery and adapt it to size. The guys who make the C.R.I.S. adapter have also attempted to capitalize on this method by making an adapter strictly for size, but frankly you can save a good bit by just digging the middle out of a
dead Wein cell. If you don't even want to spring for a couple of Wein cells (use them until they die and then dig the middles out and use them as adapters for #675 zinc/air hearing aid batteries) then a #11 rubber O-ring (about $2 at a hardware store) will work as an adapter for size. You may have to wrap a bit of aluminum foil around part of it in order to get a good electrical contact in some cameras, depending on where the battery contacts are. The #675 zinc/air hearing aid batteries only last about two weeks, but then they only cost about a buck each, and they are, environmentally speaking, relatively friendly, so who cares? In photography, that is a drop in the bucket. This is what I use in my Minoltas (I have an AL-F and a Hi-Matic 7S).
