Alternative for PX625 Mercury Cell Battery

This Olympus OM-1 uses a PX625 1.35V battery

Many older cameras and light meters were powered by the PX625 & PX13 1.35V mercury cell battery. The benefit of the mercury cell was that there was very little voltage drop over the lifetime of the battery. Unfortunately, most of these ended up in landfills, with the mecury eventually leeching into the groundwater. Because of this, mercury cell battery manufacturing has been banned in this, and many other countries. Alkaline 625 batteries are readily available but cannot be used because many vintage cameras used the constant 1.35V output of the mercury cell as a reference voltage and for powering the meter and any additional electronics. This could mean as much as 4 stops off on camera meter readings resulting in incorrect exposure. This wouldn't be too much of an issue if an alkaline battery supplied a constant voltage (after some experimentation, you would know how many stops to compensate), but it doesn't. A fresh 625 alkaline cell has a voltage of 1..5V, rapidly falls to 1.45V, and then falls slowly down to 0.9V.

1.4V 675 Zinc/Air with O-ring

Many substitutes are now available for the PX 625 such as the WeinCell MRB625 zinc/air battery. The drawback for these batteries is their relatively high cost and short lifespan. An zinc/air battery is activated by removing the paper cover allowing air to pass through holes into the battery where a chemical reaction occurs producing voltage. Once a battery has been activated, it is only a matter of months before it is exhausted. There are also many adapters (which regulate voltage by means of a schottky diode) on the market that allow the use of 1.5 alkaline and silver/oxide batteries but these are also relatively expensive.

Battery with O-ring Installed

This solution is cheap and all parts are readily available. All you need is an o-ring from the local home improvement store and a 675 1.4V zinc/air hearing aid battery from the drugstore. The variety pack of o-rings cost just under $3.00, and when purchased in multi-packs, the batteries can cost under a dollar apiece. Yes, being zinc/air, their activated lifespan is only a few months but they're cheap, and you have eleven more in the pack! O-ring measures approximately 14mm in diameter, and 2mm in section.

Bit of an electronics wiz? Find out how to make you own battery adapter HERE.

Using Canon FD Lenses with Canon EOS Film & Digital Cameras

Everyone is going digital! eBay is getting flooded with old Canon FD gear. Using a simple EF/FD adapter, you can use FD lenses on your EOS film or digital camera. Just remember; the sensors used on the 10D, 20D, 30D, 50D, and digital Rebels are smaller than 35mm format. EOS film and full-frame (35mm format) digital cameras use EF mount lenses, special EF-S mount lenses are designed for use with the smaller sensor. So, if you use an FD (or EF) mount lens on a camera designed to use EF-S lenses, what does that mean? Basically, that means a 1.6x crop factor. The film camera lens is designed to cover a 36mm x 24mm area (35mm format). Because of the smaller sensor on these cameras, this area will be "cropped" down to 22.5mm x 15.5mm. This changes the effective focal length of the FD (or EF) lens by a factor of 1.6x. For example, a 50mm lens becomes an 80mm lens (50mm x 1.6 = 80mm), a 70-210mm zoom lens becomes a 112-336mm zoom, etc. Of course, this becomes detrimental on the wide angle end as your 19mm fish-eye will get bumped up to a 30mm. Also note that FD lenses will not communicate at all with your EOS body so, you must focus and set exposure manually. If you're capable of doing this, you can find some very nice glass at rock-bottom prices!

Canon EOS 30D with Canon FD 50mm f/1.2 Lens using EF/FD adapter

Canon EOS 30D with Canon New FD 300mm f/4.0 using EF/FD adapter

Stop the Dreaded "Shutter Squeal" on Canon A Series SLRs

Well, it's not actually the shutter that's making that noise, it's the mirror escapement gear. Eventually, the mirror will not be able to get out of the way in time before the shutter opens. In severe cases, the camera will cease to function altogether. One or two well-placed drops of oil will solve this problem. This slideshow will demonstrate this procedure on a Canon AE-1 Program.

Removing the Canon AE-1 SLR Top Cover

Tutorial for removing the top cover of a Canon AE-1 Manual Focus SLR camera can be viewed HERE.

Free Vintage Film Camera Manuals

Click HERE to go to our Manuals page for downloading high quality color PDF copies of vintage camera manuals. It's FREE!