Hello everyone. I'm pretty oblivious to the world of film cameras, but after unearthing my mom's old Yashica TL-Electro the other day, I decided to test it out. I put just a cvs brand 200 speed film in it and used it mostly outdoors on sunny days at an f/8 aperture at 1/1000s (give or take). The roll had 24 exposures, and yet, when I got the roll back, I only got 8 prints. The prints that I did get back came out perfectly. When I look at the negatives, there's a big block of nothing, then a shot that I took, then a big block of nothing, then another shot, then another block, etc. I sometimes took multiple shots of the same thing, but only one of those shots would come out. I'm really confused by this...it is something that I might have done that made the rest of the photos I shot not come out, or maybe is it the generic cvs brand roll of film that I got, or is it the old camera?? Please help some that I can figure out a way to prevent this in the future! Thanks!!