Meter accuracy? Old camera - modern batteries

Discussion in '35mm Cameras' started by Peter Nielsen, Oct 29, 2003.

  1. After a brief flirtation with digital, I have arrived at a new
    appreciation of my OM-1 and early F series Nikons.

    I have heard the new alkaline button cells, at 1.5 volts, if used in
    this vintage, produce inaccurate match-needle readings.

    What is the simplest way to get around this, aside from having the
    meter professionally recalibrated?

    Does anyone still sell 1.3V mercury cells, or do I just adjust the
    f-stop accordingly to some rule-of-thumb.

    I also recall someone selling a conversion kit that allows the use of
    commonly available watch or hearing aid batteries of the correct
    voltage, but have lost the contact details.

    Thanks for your reply.

    Peter Nielsen
    Peter Nielsen, Oct 29, 2003
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  2. Peter Nielsen

    CARBUFF Guest

    What is the simplest way to get around this, aside from having the
    Im not sure what the rule is but you can just set the film speed a bit lower
    and the rest of the settings will produce proper exposure for you. If you do a
    google search you can find it. Also you can use hearing aid batteries but they
    dont last very long, maybe a month or 2, but theyre cheap. Also some cameras
    dont seem to be affected by the different battery voltage but those are usually
    the ones that only take 1 cell like my ricoh. My konica tc takes 2 and it
    definately puts the metering off. Good luck.

    CARBUFF, Oct 29, 2003
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  3. There are dropin adaptors on the market for you OM1 which accept a 1.5v
    silveroxide battery and reduce the 1.5v currency to 1,3v. So, no
    modifications on your camera are necessary.
    Succes, Gijs Rietveld
    Gijs Rietveld, Oct 29, 2003
  4. Peter Nielsen

    Larry Ng Guest
    Battery, WEIN Cell PX625 Replacement
    WeinCELL is a revolutionary new custom zinc/air battery designed to
    replace environmentally-unfriendly (and increasingly banned) mercury
    batteries. Alkaline replacements don't do the trick. Only WeinCELLs
    deliver exact voltage and stable output consistent with mercury
    batteries. Not to be confused with the hearing aid batteries that only
    last 1 month, the WeinCELL batteries last 1 year in the camera under
    normal use. . Compatible with any camera or meter specifying the
    respective mercury battery . Voltage output more stable than alkaline
    replacements. . No camera/meter adjustment or adapter required. . Up to
    10 year shelf life. Special dealer prices available.
    Larry Ng, Oct 29, 2003
  5. Peter Nielsen

    Loren Coe Guest

    cheap is correct, like 4-5bucks for 8 or 10. s/b good shelf life. the
    film speed setting is a good suggestion. regards, --Loren
    Loren Coe, Oct 29, 2003
  6. According to these guys you can't make an exposure adjustment because
    the voltage effect isn't linear. Of course, they're trying to sell their
    conversion service.

    I've gone the hearing aid battery route. It fits in well with my current
    usage. I'm virtually 100% digital, but like to get out the OM-1 and play
    with it once in a while.
    Charlie Dilks, Oct 29, 2003
  7. Peter Nielsen

    Colyn Guest

    The OM 1 can be modified per instructions on my site at or you can buy the short lived
    wein cells.

    The Nikon F's which use 2 625's are a bit more difficult to modify
    since there is not enough room in the head to add the needed 2 diodes.
    Don't waste your money. The alkaline batteries are not suited for a
    conversion because the voltage starts to drop as soon as you activate
    the meter. sells original 625 mercury cells for $8 each +
    This is known as the C.R.I.S. adapter. A complete waste of money since
    its voltage curve varies with the ambient temp.

    Colyn Goodson
    Ft. Worth, Texas

    Updated with new photos
    Colyn, Oct 29, 2003
  8. Peter Nielsen

    Colyn Guest

    Their fix is to add resistors in line to drop voltage. which in theory
    sounds like it would work.. However the problem here is resistors
    generate too much heat as current passes through which will cause
    meter inaccuracy at various ambient temp ranges..

    The best and most accurate fix I have found can be found at the below

    I have used this fix on several Minolta SRT's for sometime now with no
    meter accuracy problems..

    I have even converted one of my Weston Ranger 9 meters using 2 diodes
    inline with a machined plastic spacer in the battery chamber to reduce
    diameter to fit the s76 silver oxide batteries..

    Colyn Goodson
    Ft. Worth, Texas

    Updated with new photos
    Colyn, Oct 29, 2003
  9. Peter Nielsen

    Jim Waggener Guest

    My Nikon F2A works just fine with two 1.5v alkaline's.
    Jim Waggener, Oct 29, 2003
  10. Peter Nielsen

    Colyn Guest

    I doubt that it is consistantly accurate since alkaline voltage drops
    off considerably during use..

    Testing my F and F2 with alkaline cells produced metering inaccuracys
    of as much as 2 f stops depending on the ambient temp.

    Alkaline cells start loosing voltage as soon as you start using the
    meter whereas mercury and silver cells retain their voltage till the
    end then drop off quickly..

    Colyn Goodson
    Ft. Worth, Texas

    Updated with new photos
    Colyn, Oct 30, 2003
  11. There is the CRIS (sp?) that allows you to use 1.5V silver cells. But it's
    expensive (about $29). I've been happy using 675(?) 1.4V zinc-air hearing
    aid batteries (about $1 each) with a rubber O-ring and washer to make them
    fit the battery chamber.

    You can also buy the Wein Cell, which is a zinc-air 1.4V battery with the
    washer already on it, which costs about $6.

    Jeff Schneider, Nov 1, 2003
  12. Peter Nielsen

    Loren Coe Guest

    drop voltage? from batteries? camera button batteries???? --Loren
    Loren Coe, Nov 4, 2003
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