For many purposes the Wien radiation law is a sufficiently close approximation to the Planck equation. When it is not, the subtraction in the denominator of the Planck equation interferes with logarithmic calculation. It has been found possible to construct a table which can be entered with the negative of the exponent of the Wien equation, expressed in terms of common (Briggsian) logarithms: c2 lge/(λT), to get the logarithmic correction to four significant figures. Moreover, the same table can be used if successive approximations are necessary.
ELLIOT Q. ADAMS, "A Table of Logarithmic Corrections to the Wien Radiation Law," J. Opt. Soc. Am. 37, 695-695 (1947)