i'm new to darkroom. help please. So this is what I do not understand or, what i am having trouble understanding. i usually work with a 2 filter. Sometimes (2 times) i've used a 3 filter and have decreased the exposure seconds (or that's what i've done). I always do a test print, star at a 3 second exposure, 1'' each strip, at f/8. When the image looks right at 3 seconds or 6, i've been told to increase aperture number and multiple number. That is, if it's 3, and i move to f16, that should be a 12 second exposure (to avoid less than 10s exposure). Now my questions are the following: When an image is too bright- do i increase exposure time and increase aperture number? or leave aperture number alone and work on f/8 and only increase time?... thinking that aperture number lets in half the amount of light.. or do i only increase time? or do i change filter number? When an image is too dark, do i decrease exposure time and increase aperture number? I'm very confused with how aperture on enlarger/filter/exposure seconds affects how light or dark an image can come out. At the moment i am working with an image that i tested on a 2 filter, intervals of 1'' , 3 seconds each. the image looked "right" at 9-12 seconds, so i selected 11. Some spots are too dark and others too light, so i dodged some sections and burned others. Some mirrors are pure white. I proceeded to burn the mirrors for 6 seconds, and it's still too white. Should i do 9, 10, 11 seconds on them? or, am i selecting exposure time incorrectly? -oh, i understand how increasing aperture number lets in half the amount of light, so i compensate by adding exposure seconds.