First is the film. I just exposed most of a roll of Tri-X at 100 ISO, in error. It gave me some lovely very useable dense negatives, and some shadow detail I would otherwise not have had. With colour negative it’s even better for overexposure. We’re warned how bad underexposure is, but I like Fuji Superia under-exposed by one stop for dense blue skies and strong colours. I don’t risk that with Ektar. Slides, like digital, I don’t risk over exposure. I meter in changing light and indoors but often I trust my experience with each film. I was a great fan of the Kodak box-end exposure guide. I shot slide film for a month with only that. Hardly one was bad.