photos are often blurry
not always out of focus
just not sharp
the subject is there
but the detail is not
the assumption
it is easy to think
the focus missed
the lens is soft
the camera is not good enough
so you try to fix it
more autofocus
more sharpening
a different lens
sometimes it helps
often it does not
the real cause
blur is usually not a focus problem
it is a time problem
what blur means
a photograph records a slice of time
if that slice is too long
movement becomes visible
the image softens
where the movement comes from
the subject moves
a person shifts
a car passes
leaves move in the wind
or the camera moves
your hands are never completely still
even a small movement becomes visible
when the shutter is slow
what changes it
shutter speed
a faster shutter records a shorter moment
less time means less movement
a slower shutter records a longer moment
more time means more movement
the difference is not focus
it is duration
why it happens
often there is not enough light
so the camera keeps the shutter open longer
to gather more of it
the exposure looks correct
but the image becomes blurred
a common misunderstanding
stabilisation can reduce camera movement
it cannot stop the subject from moving
the image may still blur
seeing the difference
if only part of the image is blurred
the subject moved
if everything feels slightly soft
the camera moved
the pattern reveals the cause
the key shift
stop asking
why is this not sharp
ask
how long was the shutter open