Toronto Photography Meetup Group

If your old gear was designed to use mercury batteries there are adapters available to convert higher voltage alkaline batterys to the older mercury battery voltage

http://criscam.com/products_services/me ... _adapters/

A bit more info

The Canon EF body (wish they had called the lens something else almost impossible to search the web for EF body) has voltage regulators so no adapter is required with the possible exception of stopped down metering.
If my EF is fully fuctional It would appear that the regs are not used for stopped down metering because here the camera would underexpose by 1 1/3 stops which is about right for the higher alkaline battery voltage when comparing to the Canon F1. On the otherhand maybe there is something wrong with my stopped down metering. In my case it doesn't matter because I don't use it.

One the F1 when you do a battery check there is a tab that the meter needle is supposed to line up with if the battery is OK. What I do is change the ASA setting (ISO) until the battery check has the needle on the tab.
With the F1 you set the ASA dial to 100 and the shutter speed to 1/2000.
and flip the meter switch to battery check. When I do this this the needle is above the tab. I then reduce the ASA setting until the needle is on the tab. When the alkaline battery is fresh you will have to reduce the ASA setting by 1 1/3 stops (on the F1 anyway). But you have to check this periodiclly as the battery voltage goes down. Unlike alkaline batteries, mercury batteries had a fairly steady voltage output over their life time if the current draw was low. The higher current draw of the EF probably made voltage regulators necessary.

So any old camera that only uses the mercury battery for metering only can likely use the above procedure if it has a similar battery check function. If the camera just gives a yes no indication then you will need the adapter.

A cheaper solution depending on your use is to use a zinc air hearing aid battery, they last about 2 months once you open them and cost under a dollar each.

With the adapter it uses a smaller alkaline battery to fit the adapter that is readily available everywhere and I'm not sure you can say that about the zinc air. In a camera like the Canon F1 the battery is only used for meter and will last alot longer than 2 months. The problem with the zinc air battery is that once you pull the tab the battery is starts to discharge right away whether the the camera is on or off, all be slower when off but non the less still losing capacity. Most people don't shoot as much film as they used to so in the end cheaper zinc air could start being more expensive. The second part about availablity is also a potential problem. I would be concerned about the zinc air's shelf life. Once air gets at the cell the battery starts to go down hill and I doubt if the tab seals 100%. For the amount that I use the F1 I should be able to get at least a year or more out of the battery. I expect the 2 months that you get is mostly from just having the tab removed and not from use. I left mine on by accident in a drawer with the cap on for 5 months. because it was in the dark the meter was drawing next to no current. I've since put 10 rolls of film through it and the voltage is still up giving the same 1 1/3 stops underexposer (that I adjust for) alkaline battery and no adapter. If you are putting a lot of film through your camera the zinc air is probably the way to go, otherwise I would stick with the akaline. If you put your camera with zinc air down for a few months without using it and then pick it up the batteries will be dead, not so with the alkaline.

Even If I shoot a roll a month for single cell it's still cheaper to use zinc air then to buy an adaptor. With multiple cell system it might be different. Most if not all of those single cell adaptors don't work that well because of incorrect regulation of battery voltage but because of the latitude of film people don't really notice it. So changing the battery often is still a good solution. I buy them from a drugstore when they are on sale about $0.60 each all in so the buy back for a good adaptor is over 7 years of shooting.

These zinc air hearing aid batterys are a lot smaller than the battery they are replacing. Metrix can you tell people your solution to making the battery fit? I've heard of a number different solutions including using an O-ring. You might as well make this thread complete for battary alternatives.

I use a square sided O-ring and a small brass washer I brought for pennies from my local hardware store. Place the o-ring around the waste of the battery and the square and the brass washer on the side that is most of the case Just make sure you put the battery in the right side up. For the larger higher voltage batteries (they can use alkaline because they are regulated) like on the Yashica rangefinders you can adapt the newer smaller batteries to work by putting 2 o-rings around the body and inserting a spring from those time store miniature flash light into the camera body on the end that doesn't already have a spring.

If you're interested in better accuracy, Silver-Oxide batteries are better than Alkaline, because the voltage doesn't change as the battery wears down.

If using zinc-air, you can make it last longer by sealing the hole with tape when it's not in use.

With the Canon F1 I can by doing the battery check thing make an adjustment of the ASA dial to comp. for both higher voltage and changing voltage with the alkaline batteries. However if I pickup the Minolta Himatic RF I'm looking at it will not be so easy. I will have to make carefull comparisons to other light meters to come up with a comp. factor and I would prefer to do that not so frequently, so the silver oxide battery would be the way to go with that type of camera. Bye the way I did check that my check method worked with the F1 by comparison with other light meters and shooting a roll of Velvia.