Researching into your family tree is generally something that people get interested in as they mature. Perhaps the spark ignited after the loss of an older relative by hearing at the funeral what a life they had lead. I know that I was surprised at the funeral of one of my husband's aunts by what the vicar had to say and I regretted not getting to know her better when she was alive.
It is this realisation of the passing of time and possibly losing all that knowledge and lifetime experiences makes us want to research into our antecedants' lives which can open such a can of worms.
I got a computer program many years ago to build my family tree and I thought that it would be a lovely project for when I retired. I think the program is way out of date now but the idea is still there. The program had the facility to not only to record the birth, marriage and death dates but add a picture too. This is why when my parents passed on I took the photographs that my two sisters did not want. I felt that it would be tantamount to sacrilage to dispose of this treasure of family history.
The photos, slides and negatives that you will have, find, acquire, borrow, copy may be fragile - or someone else's - so having them digitally scanned will rescue them from possible loss and save them for the future. Also, being in digital format it will be so much easier to share amongst family by email, social media, etc., to ask, "Just WHO is the lady with Great Uncle George?"