Pentax SP1000

[rodrigo_pinto1]

I bought recently a Pentax SP 1000. In the manual of the camera the type of

batteries to use in the camera were the Mallory PX-400 or RM-400-R. Since this

are no longer avaliable, the battery that replaced this ones, the Excell

S400PX, I couldn't find in any of the photo shops of my town.

They send me to the watch shops, to find a battery. I manage to get one,the

Renata-44, that has the right height, but smaller diameter. So the light meter

works fine, but when the camera shake a bit, the batery moves and to get the

light meter to work again, I have to ajust the batery again, and again etc.

So, can I put something, a piece of paper to do prevent the batery movement?

Or it would affect the "job" of the batery or do I need to use conductive

paper,like aluminum paper (kitchen one)? Or if I do this with the last kind a

paper, do I risk it to short-circuit the light meter system?

[mtk]

Hi Rodrigo...2 easy and cheap answers. Go to a hardware store or homecenter in the plumbing section and get an "O" ring to fit around the battery and to mount it snugly. Or go to Radio Shack or other and get hearing aid batteries. They don't last that long but are very cheap and comes in a pack of 5 or 6. As a former collector of Pentax M42 mount cameras, I am told that the resistor in the meter doesn't really care if it is 1.5 or 1.35 volts.

Great camera, enjoy it!

After you are satisfied with your battery issue, if you really plan on using the meter regularly when you shoot, I would recommend you compare it to a meter on a "modern" camera just to get a feel for where it reads.

Mark

[rodrigo_pinto1]

Thank You Mark. The batteries for the earing aid are the right size? Or it's best to do the first solution? Or both? Yes, I already take a Ilford 400 B&W and, when the light meter worked, I manage to get it right. Thank You.

[walter_degroot]

check around or let someone here answer.

the pentaxes and one or more canon models had a BRIDGE type meter circuit that is less sensitive to voltage variations.

most older cameras that originally required a mercury cell had a SERIES type circuit that was very sensitive to any variation in voltage.

 

an alkaline cell starts at 1.5? volts and declines steadily over it's life.

 

all the others mercury 1.35v and wein & hearing aid zinc-air cells at 1.4v and silver oxide at 1.5 volts all have a stable voltage until they die.

 

so with any of these preferred cells, when it tells you to set at f/2.8 at 1/60 with tri-x in sunlight, you KNOW it's time for a new cell. Obviously something is wrong.

 

with the alkaline, if you pentax does not have the BRIDGE type metering circyuit, alkaline cell are very deceptive to use and can waste a lot of film, especially slide film.

 

lookin the Pharmacy dept of stores not the electronics or camera dept for hearing aid cells. they work the same as wein cel;ls but are easier to get and cheaper to buy.

[walter_degroot]

here's the manual it says mercury battery and does not mention equivalents

 

http://butkus.org/chinon/pentax/pentax_sp1000/pentax_sp1000.htm

[dougmiles]

Walter is right; no need for adapters or hearing aid batteries, since the Pentax Spotmatic has a bridge circuit that accommodates different voltages. Suggest you use the PX 625 S, a 1.6v silver cell. Works fine in mine with no change in meter accuracy... :-)

[rodrigo_pinto1]

Yes, I know the manual and that site, and yes, does no~t mention equivalents but:

 

Exell S400PX Replaces: E400N, RM400R, V400PX Battery

 

Replaces EPX400, PX400, RM400, E400N, PM400R, KX400 AWI M12 Berec BMR41, RM312R, RM400R Citizen 380-02 Duracell D325, D387, RM312, RM400R Energizer 387S, E387S Eveready 325, 387, E312N, E400N Exell S400PX IEC MR08, MR41 JIS MR41, MR41S NEDA 1116M, 1151M Panasonic H-A, H-A(p), H-B, MR41, MR41(p), NP325, WH-1 RadioShack 23-9017, 960-0430 Rayovac 387, RW51, RW57, T400N, Renata 214, 5, 502 Seiko SB-C1 Varta V325, V387, V400PX Wein Cell MRB400

 

This battery will replace discontinued mercury models. Mercuric Oxide cells that were commonly used in cameras are now banned because of toxicity and environmental fears. Most devices accommodate the small increase in voltage and function perfectly, some will need to be recalibrated

 

 

http://store.batteryspecialists.com/s400px.html

[mc2imaging]

Back in the 90's when the mercury batteries were outlawed, I made a grip for one of my

Spotmatics that had a AA alkaline battery in it to power the meter. Worked great with NO

recalibration! Since then other options have become available so I restored the camera to

normal. Still works great...

[kaymmill_64]

I too, just bought a Pentax Asahi SP1000 that needs a new battery. I found this site that sells them, but it's based in the UK. It might be worth it:

http://www.watchbattery.co.uk/shop/products/BP-PX400.shtml