How to shoot expired black and white film with Olympus μ- 1 camera?

The best way is to change the DX code on the film cassette. If you are using 400-degree expired film and intend to compensate for the secondary exposure, that is, according to 100 degree exposure, you need to modify the DX code on the film cassette as follows: Please see the attached figure. The DX code of 400-degree film and 100 degree film is only 3 and 4 digits different. At this time, you only need to scrape off the insulation layer of DX code position 3 of the 400-degree film to expose the metal, so as to make this. Then paste an insulating tape with a suitable size at position 4, so that the point cannot be connected. When shooting in this way, the camera will recognize the sensitivity of the film as 100 degrees, thus achieving the purpose of exposure compensation. If it is other sensitive membrane and compensation, please make an analogy.

In my personal opinion, it is not recommended to use photometry in the dark upstairs to compensate for exposure unless absolutely necessary. Because Olympus μ- 1 doesn't display exposure parameters, you don't know the compensation amount of each film, which will make the compensation amount of the whole film different and bring trouble to the later development.