Early photographers had to use this in order to produce photos. * O flowers
O computers
O dirt
chemicals

flower is what they needed i mea. i quess

Chemicals.

Explanation:

Photographs used to be immersed in various chemicals to produce a reaction that resulted in a visible image.

i think it's about 10 mins.

actually i think that's wrong, but i don't know how to delete this.

but who knows it might be right.