using a “Mexican hat" convolution filter and reduced deblending [see @Bertin:1996aa] (compare to the near-IR, in section \[s:observations:ss:nir:sss:reduction\], above). Then, our pipeline selects a group of moderately bright and relatively isolated sources in order to make a PSF model for each `Daophot` run. In all cases we were able to fit the PSF model to a large majority of the detected sources. Final source detection lists were slightly cleaned with the aid of `PhotVis` [@Gutermuth:2004fr] to remove spurious detections.

The resultant photometry lists showed a net reduction of up to 12% in the photometric scatter to the aperture photometry obtained with the APEX software. For the MIPS 24 $\mu$m mosaic we used the APEX aperture photometry pipeline, which was good enough for non-saturated regions of the field. In heavily saturated regions, particularly near the centers of W3-Main and W3(OH), missing pixels impeded the ability to make good measurements, and we could not improve these measurements with PSF photometry. Zero points for our Spitzer photometry catalogs were checked by direct comparison of our photometry lists with values from the GLIMPSE 360 Legacy Project catalog[^6] and from the photometry tables of YSO candidates in [@Rivera-Ingraham:2011yq]. The agreement between both GLIMPSE and [@Rivera-Ingraham:2011yq] 