  Early photometric data from the Sloan Digital Sky Survey (SDSS) contain
angular positions for 1.5 million galaxies. In companion papers, the angular
correlation function $w(\theta)$ and 2D power spectrum $C_l$ of these galaxies
are presented. Here we invert Limber's equation to extract the 3D power
spectrum from the angular results. We accomplish this using an estimate of
$dn/dz$, the redshift distribution of galaxies in four different magnitude
slices in the SDSS photometric catalog. The resulting 3D power spectrum
estimates from $w(\theta)$ and $C_l$ agree with each other and with previous
estimates over a range in wavenumbers $0.03 < k/{\rm h Mpc}^{-1} < 1$. The
galaxies in the faintest magnitude bin ($21 < \rstar < 22$, which have median
redshift $z_m=0.43$) are less clustered than the galaxies in the brightest
magnitude bin ($18 < \rstar < 19$ with $z_m=0.17$), especially on scales where
nonlinearities are important. The derived power spectrum agrees with that of
Szalay et al. (2001) who go directly from the raw data to a parametric estimate
of the power spectrum. The strongest constraints on the shape parameter
$\Gamma$ come from the faintest galaxies (in the magnitude bin $21 < \rstar <
22$), from which we infer $\Gamma = 0.14^{+0.11}_{-0.06}$ (95% C.L.).
