Most old cameras, including the
Spotmatic series, make use of 1.35V mercury cells for powering their
built-in exposure meters. Such batteries are now discontinued for
environmental protection.
Twenty years ago, when many
production cameras still used them, mercury cells were widely available
everywhere in the world while lithium batteries were only managed by Kodak
at their own premises "due to high pollution in case they are
dispersed in the environment". Nowadays, mercury cells are
discontinued for environmental protection, while lithium batteries (most
used by current equipment such as cameras, cellular phones, etc.) are
widely available everywhere in the world. Is it possible that mercury
pollution danger raised during the years (when equipment using them
decreased so much) while lithium pollution decreased (when equipment using
them increased so much)? I strongly doubt it. However, that's the way
things are in our crazy world.
So in practice mercury cells are no
longer available. In order to replace such old batteries, some people
modified the battery compartment of old cameras for accepting 1.5V silver
oxide cells (both mechanical and electrical modifications could be necessary),
while others adapted smaller watch-type 1.35V zinc-air cells (only simple
mechanical adaptation necessary).
According to information from Gene
Poon from Spotmatic discussion group (http://groups.yahoo.com/group/spotmatic)
such 1.35V voltage batteries can be replaced with any matching 1.5V
battery (silver oxide type are good). That's because original SP, SPII,
SPIIa, SP500, SP1000 all use a bridge
circuit where the meter measures the balance between the two legs of
the bridge. Both legs of the bridge would be equally affected by any
"normal" voltage variations. SPF uses a dual coil meter, the two
halves equally affected by any voltage variations.
In case you want to stick to 1.35V, probably the best solution
is using dedicated zinc-air cells, giving correct voltage (1.35V) and
having proper size, thus meaning no special adapters required and maximum
battery life.
When using zinc-air cells, they have
to be activated by removing protective labels on them, allowing air to
enter the cells. Be sure not to activate zinc-air cells before actual use,
since once activated the battery will last one year no matter how much you
use the camera. That's the drawback of zinc-air technology and the reason
for using mercury cells in the past. Storage life of non-activated
zinc-air cells is stated to be ten years.
And now the most important question:
where can you find dedicated zinc-air cells for your beloved camera? As
far as I know, currently they are only manufactured by Wein Products, and
distributed worldwide by Micro-Tools (www.micro-tools.com).
By visiting their website, you can access your world region and in case
order your battery online. However, since Micro-Tools is the world's
largest supplier of camera repair tools and supplies, you can also get
WeinCells via your favorite photo repair lab.
Don't expect bargain prices: after
all worldwide demand for such batteries is quite low and Wein has monopoly
on them. As a reference, currently (April 2003) Micro-Tools European
website sells WeinCells at 8.12 Euros each.
Here is a table with most common
vintage cameras using mercury cells and their WeinCell replacement models:
Make
|
Model
|
Industry
standard (mercury) |
WeinCell
replacement |
Asahi
Pentax |
Spotmatic,
Spotmatic II (SPII), Spotmatic IIa, SP500, SP1000 |
PX400 |
MRB400 |
Fujica |
ST701,
ST705 |
Asahi
Pentax |
Spotmatic
F (SPF), Clip-on exposure meters (SV, S1a) |
PX625
/ PX13 |
MRB625 |
Canon |
7s,
EF, EF2, EX, F1, F1n, FT, FTb, FTn, Pellix, TL, TLb |
Edixa |
Prismaflex,
Prismat, TTL |
Exakta |
TL500 |
Gossen |
LunaPro |
Kodak |
Retina
IF, Retina IIF |
Konica |
Autoreflex,
T3, T4, TC |
Leica |
CL,
M4.2, M5, Leicaflex, Leicaflex SL, Leicaflex SL2 |
Minolta |
SR
series, SRT series |
Miranda |
Automex
III, FM, FV, FVT, G, GT Laborec, Q, Sensorex, A, B, C |
Nikon |
Nikkormat,
Nikkormat FT, Nikkormat FTn, Photomic F, Photomic FTn, Photomic T |
Olympus |
FTL,
OM-1, OM-1n, Pen D2, Pen EE, Pen F, Pen FT |
Pentacon |
Six
TL, Super |
Praktica |
LTL,
LTL3, MAT, MTL, MTL3, Super TL, Super TL, Super TL2, Super TL3 |
Ricoh |
Auto
TLS EE, Flex TLS401, Singlex, Singlex II, Singlex TLS, SLX500 |
Rolleiflex |
SL35M,
SL350 |
Topcon |
RE
Super, RE2, Super D, Super DM, Uni, Unirex, Unirex EE |
Yashica |
Mat
12, Mat 124, Mat 24, Penta J3, J4, J5, J7 |
Zeiss
Ikon |
Contarex
S, SE, Super, Icarex 35, 35BM, 35CS, 35S, 35SBM, 35STM, 35TM, SL706 |
Edixa |
TL,
T500, T1000 |
PX675 |
MRB675 |
Exakta |
TL1000,
TWIN TL |
Konica |
Autoreflex
A3, T, T3 New |
Miranda |
Auto
Sensorex EE, Auto Sensorex EE2, Sensomat, Sensomat RE, Sensomat RS,
Sensorex II, Sensorex RE |
Minox |
B,
BL |
Olympus |
Pen
D3 |
Ricoh |
Hi-Color
35/35s |
Topcon |
IC1
Auto, IC1N |
Yashica |
FX2,
FX3 |
|