This is something I have been looking into for a long time. I have contemplated and then scrapped the idea of buying a scanner just for negatives. The last time I looked into things, I found a few ways to scan negatives with a regular flatbed scanner. I read a few reviews of the methods and they were meh, at best. One thing I did find was someone being a nice troll (is that a thing?) a leaving comments in those methods that said,"Hey, do this instead. It actually works." So, the this instead? Let me jump back a little bit:
In order to scan negatives properly, the light has to reflect back into the scanner. Most flatbed scanners have the white cover on top, not really allowing for reflection. One method that I haven't tried because I'd like to modify it is creating a reflective triangular dome with silver cardstock. This was the method that people were "meh" about. The method that the nice troll kept adding was to open a white screen on your smartphone (I used a blank Pages document on my iPhone), place behind the negatives on the flatbed and leave it open. The above image is my very first results with this. It's a ten year old photo from my Photo I days. The next few I'll add were supposed to be a step-by-step photo essay practice for Photo II so that we could practice creating multi-windowed mats. I don't remember if I actually used this, or created something else to tell a story. It's funny to look back at all of these ten year old negatives. Now I can just get my negatives developed without paying for them to be scanned in at high resolutions! Ayyy! Saving money :) Soon, I'll be developing my own film at home. ~dances~
I could have cleaned these up a LOT better with Photoshop, but I was so excited I had to share. Photoshop = way easier to use that inking photos to fix dust and hair, let me tell you! If you're actually using this as advice, don't forget to invert your negatives because they're negatives, duh, and correct contrast, etc.