OM-2SP Shutter speed lag in AUTO mode

jkfromsk · Sep 25, 2025

I have an used OM-2SP and the shutter speed is slow in AUTO mode despite the light meter being accurate. Shutter speeds in manual work well and the light meter works as intended.
I have other Olympus cameras (3ti, 4ti, and another 2sp) that I tested using the same ISO settings and they all shot at the same speed, with the same exposure settings.

i.e. Broken 2SP @ f1.8 says 1/120s , shoots at around 1/4s

Anyone else have this issue? any easy remedies before i pay someone to CLA?

MattKing · Sep 25, 2025

The OM-2SP has two metering systems. The one that gives an indication in the viewfinder, and the other that, in Auto mode, reads light reflecting back off the film surface and controls the duration of the exposure based on that.
If there isn't any film loaded, the black pressure plate reflects much less light, and the auto exposure will be longer than what is indicated by the viewfinder indication.
And in case you are wondering, I'm pretty familiar with the OM-2S(P) - this is mine, bought new when they were current, displayed with the box end of the last roll of Kodachrome shot with it before processing ended in 2010:

Hope this helps.

jkfromsk · Sep 25, 2025

MattKing said:
The OM-2SP has two metering systems. The one that gives an indication in the viewfinder, and the other that, in Auto mode, reads light reflecting back off the film surface and controls the duration of the exposure based on that.
If there isn't any film loaded, the black pressure plate reflects much less light, and the auto exposure will be longer than what is indicated by the viewfinder indication.

Right I understand now thank you. However, what about the fact that my other cameras are shooting consistently without film? This 2SP is the only one thats acting differently.

MattKing · Sep 25, 2025

Are you testing any of your cameras with film loaded, and are you basing your conclusions on the exposed frames?
The different auto-exposure capable OM cameras employ the OTF metering in slightly different ways, so it isn't strange that you will see some differences if you are testing without film, but such a test isn't a very reliable indicator.
IIRC, midway through their production runs, Olympus started supplying some of the early OTF metering models with protective cards on the pressure plate with a reflectance closer to that of film, because customers in camera stores were confused by the slow sound of the shutters when film-less cameras were being demonstrated for them. I can't remember whether the OM-2S (as it was badged in our market) was one of those, but I do remember showing OM-10 cameras to potential customers and having to explain to them the phenomena.

jkfromsk · Sep 25, 2025

MattKing said:
Are you testing any of your cameras with film loaded, and are you basing your conclusions on the exposed frames?

to keep things consistent, i tested with no film. im just perplexed that each camera was getting consistent results

Bill Burk · Sep 25, 2025

The Olympus automatic cameras all meter off the gray film during exposure.

If you have no film they see the black pressure plate that’s really dark.

By design, and because you have no film. The cameras will all give you an unnervingly long shutter time.

Soon as you put film in the problem goes away.

MattKing · Sep 25, 2025

Kindly describe your test method.
If it involves a separate shutter speed tester, I would expect exposures with the cameras set to Auto would be totally confused by the presence of the tester.

Bill Burk · Sep 25, 2025

I’d assume by ear. The first time you encounter this engineering marvel it’s a shock.

But when you read about the dozens of film stock Maitani studied to arrive at the gray value standard that would work best inhis cameras, you’re going to be impressed.

jkfromsk · Sep 26, 2025

MattKing said:
Kindly describe your test method.
If it involves a separate shutter speed tester, I would expect exposures with the cameras set to Auto would be totally confused by the presence of the tester.

I just tested with film inside the cameras and i can confirm that the broken 2sp is shooting slower than the other cameras.

with film:
the broken 2sp shoots at 30 when meter reports 120
the non broken 2sp, 4ti both shot at 125 when meter reports 120

doing this mostly by eye and ear, switching from manual to auto

MattKing · Sep 26, 2025

So you are listening to the different shutter sounds in order to determine what the exposure length is?
And you are comparing those with what the 2nd metering system in the cameras is reporting?
Are you using the exact same lens on each camera body?
How are you ensuring that the two cameras are metering from the exact same light?

Chuck1 · Sep 26, 2025

Just behind the mirror is an angled plate holding what looks like a rectangular fresnel.
Sometimes it falls out.

jkfromsk · Sep 26, 2025

MattKing said:
So you are listening to the different shutter sounds in order to determine what the exposure length is?
And you are comparing those with what the 2nd metering system in the cameras is reporting?
Are you using the exact same lens on each camera body?
How are you ensuring that the two cameras are metering from the exact same light?

I'm using the same exact same lens (50mm/1.8) on the exact same subject (lamp in my room) setting the exact same exposure on another working 2sp.
I used manual to get the accurate shutter speed and compared it to what I heard in auto mode. The working 2sp worked as intended (light meter said 125, shutter speed shot at 125), however the broken 2sp was shooting at the incorrect speed (light meter says 125, shutter speed shooting at 30)
tested both with film

OM-2SP Shutter speed lag in AUTO mode

jkfromsk

MattKing

Moderator

jkfromsk

MattKing

Moderator

jkfromsk

Bill Burk

MattKing

Moderator

Bill Burk

jkfromsk

MattKing

Moderator

Chuck1

jkfromsk

OM-2SP Shutter speed lag in AUTO mode

Moderator

Moderator

Moderator

Moderator

Privacy & Transparency

Privacy & Transparency