Why doesn't 2+2 = 4 in print exposure?

[ruilourosa]

people, please calm down, ansel used a metronomer. do some test strips. experience is useful. i never found enlarger delays very problematic, keep times a bit longer than 20 secs. keep it simple you will need the energy in your legs and your mind not to give up printing after 6 hours in the lab

 

[RalphLambrecht]

people, please calm down, ansel used a metronomer. do some test strips. experience is useful. i never found enlarger delays very problematic, keep times a bit longer than 20 secs. keep it simple you will need the energy in your legs and your mind not to give up printing after 6 hours in the lab

Don't worry; we're calm. Nevertheless, timer delay can be a problem when doing test strips ala Fred Picker.