system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: People today are able to produce paintings that are indistinguishable from photographs. Why couldn’t artists in past eras achieve this level of realism?
gpt
Quality of materials, (paints, brushes, canvas) time, painting detailed pictures requires a lot of time and you have to be able to afford to spend that much time on a single painting, lack of photographs as reference, until Vermeer, who may have used a kind of pinhole camera to create their pictures still images of the subject were not available.