Lukasz Grabun wrote:
> Hello there,
>
> it's my very first post here though it's been few months since I
> subscribed and followed the list. I am relatively new photography and very
> new to OM system (two weeks!). However, I've been shooting digital Olympus
> camera E-1 for more than a year now, using mostly old M42 manual lenses.
>
Welcome to the active list!
> Here's my story.
>
> Few days ago I tested my OM-2n. Generally, it looks fine and OK-ish but
> one thing seems to be broken - the lightmeter.
>
Before going any further, you need to understand something about the
OM-2 and 2n. These cameras have two completely separate light meters.
the one that operates the meter needle in the viewfinder is there both
to give readings for manual use and to give a rough idea of what
exposure you will get in Auto mode.
The second metering system is the TTL auto exposure system. It does not
start to operate at all until the mirror goes up prior to the shutter
opening. This is because it can't operate with the mirror down, as it
can't see the first shutter curtain with the mirror in the way.
In Auto mode, in the very brief period after the mirror goes up and
before the shutter starts to operate, the TTL sensor on the bottom of
the mirror box reads the light reflected off the pattern of silvery and
dark patches on the front of the first shutter curtain. As the first
shutter curtain starts to uncover the film, the TTL sensor is reading a
combination of curtain pattern and film. As soon as it senses enough
light for the required exposure, it releases the second curtain. This is
a wonderful, and when introduced, revolutionary, exposure system, as it
can even react to changes in light during the exposure. On the other
hand, it can't tell the user anything about what it is going to do
beforehand.
Thus the other system, which is similar to the match needle system of
the OM-1(n), and reads the brightness of the focusing screen with a
couple of light sensors in the prism housing.
So, it is entirely possible for one system to be operating properly
while the other is inaccurate, as would appear to be the case for you.
> <snip details>
>
> I had the film developed today. To my great surprise most of my manually
> set frames were overexposed whereas those taken in AUTO mode - even though
> the needle indicated time ten times longer than one would judge by
> listening to the sound of shutter - are properly exposed.
>
The shutter sounds the same from 1/60 to 1/1000 second, because of the
way a focal place shutter works. Personally, I can't reliably discern
the difference between any of those speeds and 1/30 unless firing
repeatedly without film while listening carefully.
Looks like your camera needs a CLA.
Moose
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