Reading fog before sunrise

Fog is not random. If you learn to read the night before, you can be standing in the right valley when it forms.

Radiation fog needs three things: clear skies, light wind, and moist ground after a cool night. When the evening forecast lines those up, I set the alarm an hour before civil twilight.

Where it pools

Cold air sinks, so fog collects in low ground — river bends, hollows, the field behind the old mill. I scout these in daylight so I'm not stumbling around in the dark.

Exposure

Fog fools the meter into underexposing. I dial in +0.7 to +1.3 EV and check the histogram — you want the bulk of the tones pushed right, not muddy grey.