Contact 1

Good Afternoon,

It looks as if you simply have negatives of varying degrees of exposure--not exactly an unusual situation with a roll of 35mm shots of different subjects under different lighting conditions. Judging by the frame numbering and some of the shots, it looks as if your contact sheet has been properly made; I think some of the frames show as black (or almost so) just because they're seriously underexposed. This is what a contact sheet is for--letting you know which frames are OK and which ones are duds.

Konical

if you are really in need of seeing your under exposed views
you could always make a contact sheet by doing a test strip for THOSE frames
and boost your contrast filter a bit ... keep in mind, you will end up with
2 contact sheets, this one you have posted, and the second one,
which will show the frames that are black now, but not the others.
kind of like the negative of this sheet

have fun!
john

Agree. Contact sheets act as a 'proof' of your consistency of exposure and development, letting you know how difficult the negatives will be to print. With time and experience, your contacts will look much better. Also, there is a standard way of printing them so you know you are getting the most. It's not to everyone's taste, but PM me if you want to hear more about it...