A CPU 11 in a digital camera 1 determines that the photography environment is dark and includes a spot light source, in the case where the number of pixels that have a higher luminosity than a first threshold to the total number of pixels in the focus area exceeds a first certain proportion and the number of pixels that have a lower luminosity than a second threshold to the total number of pixels in the focus area exceeds a second certain proportion, on the basis of a luminosity signal Y which has been acquired. Subsequently, the CPU 11 reads out a coefficient value of a cut-off frequency from a memory 110, inputs it to an HPF 9 thereby setting the cut-off frequency fc higher.