Already activated at the factory, the automatic sensitivity setting of the OM-1 needs to be given more attention. Most photographers keep the basic settings the same. But this allows a lot to be controlled. In the standard setting, the sensitivity is changed depending on the focal length. This is where the rule of thumb of 1/focal length as the longest exposure time comes into play. For example, if you use a 400mm lens, the sensitivity is consistently increased when the camera can no longer ensure a shorter exposure time. The automatic mode is beneficial when using a zoom lens. However, if you want to ensure the exposure time stays within a specific value, this automatic function can also be counterproductive.
For this purpose, the OM-1 offers the option of changing the automatic sensitivity setting depending on the exposure time. To do this, proceed as follows.
1 Under the first camera menu in the third tab you will find an entry “ISO-A Min. Navigate there and press the OK button.
2 Select the exposure time from which the camera should increase the sensitivity and press the OK button again.
That’s all you need to do. Your camera will now change the sensitivity as soon as there is a risk of the exposure time being undercut.
If you need more details on adjusting the ISO sensitivity, I recommend my article “Automatic ISO setting adjustment“