Hello, how are you?
Good. Photography really is a science as well as an art form. 
That is an fun way to put it. What kind of variables are there in photography? 
I think the focus like in pictorialism is one variable. 
I have always been curious about flash. Is it recommended to use it outdoors?
Using a flash really depends on the time of day the picture is being taken during as well as weather conditions
I am sort of new to photography, can you explain ISO to me?
Film speed
Film speed is the measure of a photographic film's sensitivity to light, determined by sensitometry and measured on various numerical scales, the most recent being the ISO system. A closely related ISO system is used to describe the relationship between exposure and output image lightness in digital cameras.
Relatively insensitive film, with a correspondingly lower speed index, requires more exposure to light to produce the same image density as a more sensitive film, and is thus commonly termed a "slow film". Highly sensitive films are
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