My guess is what they mean by unprocessed is that the negatives had not been printed. I do not believe the latent image would remain for 100 years. Then again maybe the cold does keep them.
I know I found a roll of 120 film at my grandmothers which had been lying on top of a safe for over 10 years. I had it processed and there was just the faintest image on two of them and the rest were totally blank.
> I do not believe the latent image would remain for 100 years. Then again maybe the cold does keep them.
Four years ago, a friend found a box of color 8mm movie film in his attic. They were 40 years old and never developed. His son begged him to develop them and he finally got them developed. 1/3 of them were worthless. The other 2/3s were as if they had only been taken the day before. They were perfect.
“I know I found a roll of 120 film at my grandmothers which had been lying on top of a safe for over 10 years. I had it processed and there was just the faintest image on two of them and the rest were totally blank.”
You had bad luck. I found a roll of exposed film at my grandparents house that was over 20 years old. It was B&W Kodak Verichrome Pan. Kodak sold a special additive chemical that I mixed with D-76 developer to reduce age-related fogging. The negatives turned out well and proved to be pictures of me and my sister when we were little kids.