Photographs that make me sad? Photographs of sad people, sad events, photographs of people I've loved who I don't see anymore, for whatever reason. Photographs of the sun shining when I'm sitting looking out at the thundering rain. Photographs of smiles when I don't know or remember the reasons behind them. Photographs of Christmas morning when it's the 26th of December and you know you couldn't possibly be further away from this again.
Photographs of childhood, because you'll never be that innocent again. Photographs of weddings because everything looks just that little bit too perfect, yet can fall apart so easily. Family photographs - the one's where someone shouts "Cheeeeeeese!" and everyone smiles, even though no one wants to.
I think I answered the question this time.