Olympus OM2n meter problem

Hi new poster so hope you are kind with me.

I have 2 om2ns one meters perfectly the other meters two stops under, but occasionally gives correct. I tried feeding them SR44s to stabilise the charge they received. Issue persists. Anyone else got ideas to try here?

Perhaps not the solution you are looking for, but if it were me I would send it to a camera repair person to see if they can repair the meter (possible bad connection somewhere in the body?). If was repairable I would ask them to go ahead with a full CLA. That way you would end up with an accurate, reliable body for years to come.

Meters, or exposes? The OM2n has a set of CdS cells in the finder for metering, but the actual exposure is done from cells in the mirror box reading the film plane. If there is an issue with the observed exposure setting, it may not affect the exposure. Do you get different behavior with On' and 'Auto'? It could be a switch problem.

Related to grahamp's explanation, as the OM2n meters off the film plane, it will meter differently if film is in the camera than if there is no film.
The viewfinder display does not change.
In addition, there are newer viewing screens that will fit an OM-2n but will affect the displayed meter reading. Check to make sure that the two cameras don't have different screens (of the types that matter).

grahamp said:

Meters, or exposes? The OM2n has a set of CdS cells in the finder for metering, but the actual exposure is done from cells in the mirror box reading the film plane. If there is an issue with the observed exposure setting, it may not affect the exposure. Do you get different behavior with On' and 'Auto'? It could be a switch problem.

Click to expand...

This.

Not only that, but the type of sensors used is different. The OTF metering uses the fast advanced SPD sensors. The regular metering uses the old fashioned CdS meters.

This means the two metering systems will seldom agree... For them to agree you would need to point to an uniform wall lit by daylight. If you're lighting with artificial light or colored light, the spectral sensivities of those two sensors differ!!

So, the OM-2 has a really advanced meter in the auto mode and a quite old-fashioned meter in the manual mode.

CdS cells in some cameras tend to age so this might be at culprit. But perhaps a recalibration solves everything.

Thanks guys. I knew about the two meters. Both auto and manual are the same reading. Also both have the same focussing screen. Both cameras also differ both with and wIthout film - looks like recalibration is the answer

Sometimes it's two stops low, sometimes it's OK, right?

Well, being low, it's not light entering the eyepiece around your eye. On a bright day, light intruding around your eye will make the needle on most OM's deflect as much as 2 stops! Shade with your hand, and the needle drops to accurate. So unless it's actually the first 2n that's reading high instead of this one being low....

One thing to check: In a well lit room, center the needle, then move your hand back and forth across the lens to vary the amount of light entering the lens while you watch the needle. The needle should move smoothly up and down as the light varies. If it seems to hang, it could be that a small piece of metallic debris may have "stuck" to the magnet inside the galvanometer. Sometimes a tiny sliver of metal from who-knows-where in the camera will float around until it gets attracted to the magnet at the center of the galvanometer, then it will "stand up", hanging or dragging on the coil frame to which the meter's needle is attached. Then, for whatever reason, the tiny sliver may "lie down", and everything works fine for a while -- until that sliver stands erect again, and the needle stops moving smoothly once more.

If this is the case, the top cover will need to be removed, then the "top hat" over the galvanometer's frame, and the magnet at the center of the galvo will need to be carefully and thoroughly inspected for any debris attached to it. If anything is found adhered to the magnet, a small metal probe can be delicately introduced to attract the metal debris, knowing that the probe will be pulled by the meter's magnet, so hold it firmly! If the metal probe is pulled from your grip, it may damage the meter!

One other problem, though never intermittent, is if one of the tiny coil springs at the top or bottom of the galvanometer "loops" around one of the weighted pins used to balance the coil frame so that the meter reads accurately no matter how it is oriented. If this happens, the "looped" spring will pull the needle away from it's proper location. When this happens, though, the needle will appear to move sluggishly and jerkily, and instead of slowly floating to a stop after varying the light entering the finder, it will stop almost immediately. It is possible to carefully pull the coil spring out from beneath the pin, then press the pin down against the coil frame so that it won't happen again -- but this procedure is even more risky than the one above!