Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 69,914   Posts: 1,521,726   Online: 1071
      
Page 3 of 4 FirstFirst 1234 LastLast
Results 21 to 30 of 39
  1. #21

    Join Date
    Jan 2005
    Location
    Minneapolis, MN US
    Shooter
    Multi Format
    Posts
    2,206
    Images
    4
    I've used the adapter described here: http://www.buhla.de/Foto/batt-adapt-US.pdf

    I purchased, rather than build mine. It has worked very well with my Rollei 35 and Canonets with a silver oxide battery. I've also used hearing aid batteries with appropriate spacers in my Spotmatic.

  2. #22
    PeterB's Avatar
    Join Date
    Apr 2005
    Location
    Sydney, Australia.
    Shooter
    Medium Format
    Posts
    597
    Quote Originally Posted by Ryuji
    Zinc air cells are good in terms of voltage stability... but they don't last long once used.
    Ironically Zinc air cells have the highest capacity [mAh/kg] of ANY commercially available battery technology available today.

    There is one type of zinc air cell being made specifically for photographic equipment to replace mercury cells, but they charge a premium for them because they have no competitors. They are known as Wein cells see [color=#800080]http://www.weincell.com/[/color] Don't believe all the marketing hype they sprout on their site (there are errors), but I think the one year shelf life (after peeling off the tab) could be credible.

    I have tried to find out more info from them directly, but until they reply to me I am assuming that they have simply made the air holes smaller. Having smaller air holes means a lower maximum current (not a problem for camera meters), but it also means that they should take longer to (self) discharge as the oxygen can't diffuse through as fast.

    The other disadvantage of zinc air cells them is that the maximum current (i.e. amperage) they will deliver is substantially less than both alkaline and much less than silver oxide (and also mercury cells), but this should not be a problem for the camera meters which draw small currents (much less than the 10 to 15mA limit of zinc air cells)

    regards
    Peter

  3. #23

    Join Date
    Dec 2004
    Shooter
    Multi Format
    Posts
    1,670
    Quote Originally Posted by Doug Knutsen
    As a sucker for any rangefinder camera, particularly ones branded Yashica, Konica, or Canon, (but I'm not really choosy - as long as the camera is a rangefinder) I snap them up whenever I find one at a garbage sale. Batteries for them? No problem, if you're in the U.S.. Just go to "Batteries Plus." They've always had suitable replacements for the old mercury jobs. I checked with the local store (Salem, OR) and they told me they have over 200 stores across the U.S.. Sure beats messing with soldering guns, expensive adapters, etc.
    Doug
    While you may find a battery that is the correct physical size, other cell characteristics may make it unsuitable as a replacement for a mercury battery. Some cameras use a bridge circuit that is tolerant of voltage differences. However some camera circuits may be damaged by higher voltages and amperages than those for which they were designed. The only batteries currently available in the US for camera use are alkaline, silver oxide, zinc-air and the older carbon-zinc types. Only the zinc-air cells are a safe direct replacement for mercury cells. The other choice is to reduce the voltage of a silver oxide cell by using a converter or by modifying the camera circuit.

    Lastly and most importantly, alkaline and carbon-zinc batteries cannot be used because of the steep voltage change during discharge. One of the reasons a mercury cell was originally used in these cameras was because there is only a small voltage change until almost the end of the cell's life. Today only a silver oxide cell has the same characteristics as a mercury cell.

  4. #24

    Join Date
    Mar 2005
    Location
    Polk County, Oregon
    Shooter
    Medium Format
    Posts
    49
    Gerald: Are you telling me that the alkaline batteries I get from Batteries Plus are potentially harmful to my cameras? I have six different Yashicas from the Electro 35 series, all of which I love, and if I'm liable to damage them with the alkaline batteries I'll switch over to adapters. (I'll also quit telling people to get their battery replacements from Batteries Plus!)

    Doug

  5. #25

    Join Date
    Dec 2004
    Shooter
    Multi Format
    Posts
    1,670
    The Yashica Electro 35's seem to do well with alkaline batteries as their circuit is not that voltage sensitive. I have several myself and they seem to do quit well. What I am referirng to are those cameras that have a match needle meter design and use a button battery like the 675. For such cameras a zinc-air or silver oxide cell is usually required.

  6. #26

    Join Date
    Mar 2005
    Location
    Polk County, Oregon
    Shooter
    Medium Format
    Posts
    49
    Gerald: Thanks for the reply. I'm glad to know I'm not risking damage to my beloved Yashicas. I AM going to be more careful about recommending Batteries Plus in the future.

    Doug

  7. #27

    Join Date
    Jan 2005
    Location
    Boston, MA
    Shooter
    Multi Format
    Posts
    1,416
    Quote Originally Posted by Gerald Koch
    What I am referirng to are those cameras that have a match needle meter design and use a button battery like the 675. For such cameras a zinc-air or silver oxide cell is usually required.
    1. In match needle meters the current going through the meter is unchanged as the voltage is changed. So the difference is the power dissipated by the resistor network. The ratio of the dissipated power is the ratio of the voltage squared, or 23% more. Are you seriously arguing that this difference can burn the circuit?

    2. How does silver oxide help in the voltage difference part compared to alkaline cells?

  8. #28

    Join Date
    Jan 2005
    Location
    Boston, MA
    Shooter
    Multi Format
    Posts
    1,416
    Quote Originally Posted by Gerald Koch
    The only batteries currently available in the US for camera use are alkaline, silver oxide, zinc-air and the older carbon-zinc types.
    This is not true. Several lithium cells are available. Some of the lithium cells are in the size of two SR76's stacked up, and it's called CR1/3N. It's a very useful battery.

    Lastly and most importantly, alkaline and carbon-zinc batteries cannot be used because of the steep voltage change during discharge.
    This is not true. They can be used, as long as the voltage and/or the meter is adjusted. It's just that the meter reading is less accurate when the battery is halfway in its life.

  9. #29

    Join Date
    Jan 2005
    Location
    Boston, MA
    Shooter
    Multi Format
    Posts
    1,416
    Quote Originally Posted by PeterB
    Ironically Zinc air cells have the highest capacity [mAh/kg] of ANY commercially available battery technology available today.
    While zinc air may have high energy density, its lifespan is limited by the other factor. My Konica Autoreflex T's never required battery change since I put in a fresh CR1/3N 10 years ago. My Konica Hexar never required battery change since I put in 2CR5 many years ago. My Auto S2's never required battery change since I put in alkaline cells when I repaired them many years ago. (I don't know if there is 625-sized silver oxide cells but I couldn't find any at that time.) Auto S2 doesn't even have a power switch and I make no effort to get last drop out of the battery. But with zinc air, you'll have to tape the hole or something when not in use to get several months of use. That's a bit too much work for me. (Opinions vary on this one. I'm lazy.)

  10. #30

    Join Date
    Jan 2005
    Location
    Boston, MA
    Shooter
    Multi Format
    Posts
    1,416
    Quote Originally Posted by Woolliscroft
    Using OM cameras with slide film I do find a just noticable underexposure using 1.5v batteries, although it's only very slight.
    If you mean Olympus OM-1 or OM-2, you shouldn't have any exposure error due to the battery voltage difference since they have a match needle meter.

    AE cameras don't use match needle. The first AE mechanism was Konica's lock-needle design and this (and most other) type of meter is susceptible to voltage difference, particularly when the light level is high.

Page 3 of 4 FirstFirst 1234 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin