I had a Portrait Shooting with Expired 35mm Film, and I was surprised about this amazing result.
20 years ago our fine art high school manager gave me 10 roles in black and white Forte Pan Films as a Gift, this is one of those films. After Digital Cameras were born, I didn’t shoot on analog Film for a long time. This film expired in 2005.

Exposing time for Expired 35mm Film during photography and developing time

before shooting, I made so much research about exposing and developing time, but I was confused about it because there is so much information on YouTube, that some photographers say, they overexposed during the photography. But I decided to do nothing and just shoot with the correct exposure time which my light meter shows me. Also, during developing my Film, I did not change anything.

This film that I used was 15 years expired Film maybe for the other films with longer expired time(30-40 years) you might to shoot over or under Exposed

How to minimize expiring time for photography Films

By keeping the films in a fridge, you can minimize the expiring time. To make a photographic film, layers of gelatin, some of which are filled with silver halides (a combination of silver and halogen), are coated onto a flexible plastic sheet.

Silver halides are the light-sensitive part of photographic film and react to light exposure. Anyway, these coated sheets are dried, you need to cut them into smaller pieces, put them in boxes, and sold to people like you and me who go and cut the pieces of the film before dipping them to expose chemicals to light.

Photographic film has an expiration date because – in the case of the black and white film – halides lose their sensitivity over time. Time, heat, humidity, nuclear collapse, and even the glow after creation all play a role. Together, they make changes to silver halides, making them less or more unpredictable in light-sensitive.

We generally refer to this effect as fog. As you know color film using paints and masks, which, like Harlequin lasagna with/between layers of silver halide, adds a little more complexity to the composition. Colors decompose very quickly compared to silver halides, and sometimes very quickly relative to themselves. This is not a phenomenon that is limited to photography. I hope this information will be useful for you.