| This page provides links to various images
taken from an urban setting. It can be a challenge to pull detail out
of objects that are buried in light pollution. Various techniques were
used to pull the detail out of urban light pollution and each is
detailed in the table below each image. All of the techniques share one
thing in common in that they take sky limited exposures. That is the
individual sub-exposures are long enough so that photon noise from the
sky background is the dominant noise source. With the subs sky limited,
all that is left is to take many sub-exposures and stack them. This
effectively means that long exposure times compensate for the added
noise due to the bright sky background. It really did not matter
whether high or low ISO was used or the focal ratio as long as the
total integration time is long and each sub-exposure is sky limited. |
