35 SP spotmeter question

[Satumango]

I just bought a 35 SP a couple of days ago; it was only 5 euro so I couldn't resist. It does have a dirty front lens and some spots on the back element, so Iĺl will have to have it cleaned. It worked on manual and when I put in a new battery (original mercury PX625) it worked on "auto" too! However the lightmeter seems to be off quite a bit and when I try to use the spotmeter the needle goes all the way to the right: it seems that the spotmeter is completely dead.

Does anyone know how the spotmeter in the 35 SP is implemented? I kind of assumed it uses the normal CdS cell for that with some sort of mask to restrict the field of view when the spotmeter button is pressed. But since the normal lightmeter (although not accurate) works and the spotmeter does not, I'm starting to think that the spotmeter uses a separate cell.

Could someone please shed some light on this?

Thanks!

 

[rayfoxlee]

Some time since I owned an SP, but I do know that the single button cell drives the meter, no matter whether it is in spot mode or not. There may be some sort of relay malfunction from the spot button on the back. These cameras are over 40 years old I guess now, so a few glitches are to be expected.

Hope you sort it!

 

[Satumango]

Rayfoxlee: sorry, I was a bit vague, with "cell" I meant the light meter CdS cell, not the battery. I should have been more specific. But it could indeed be a relay problem and I need to have it serviced anyway. Thanks for the informative answer.

 

[John Hermanson]

Sometimes resoldering all the cds connections makes the spot section of the cell work. If not, then the cell is bad. Long unavailable. It's an odd design, flat, about 1/2" square, with a central area handling the "spot" duties. John

 

[jmc56]

I have an Olympus SP which is one of my very favorite rangefinders, which is saying something given that I have other Olympus and collect Leica (M6TTL is the most recent, earliest dark ages) and cut my teeth on Nikon SPs when they were new.

If there was something wrong with my Oly SP or any other SP, I'd send it to John Hermanson at zuiko.com to have it done. The price for an overhaul might be more than you'd pay for another, but when he's done, it's a first rate job. I'm overdue to sen him some OMs.

 

[John Hermanson]

The SP cds cell has 3 wires coming out of it, 2 zones of metering, central area for spot. You're lucky it works on plain auto, though if the cell is bad, there is no substitute. Alkaline 625A, 625U are 1.55V and can cause 2-3 stop error anyway. John