  The 3D-HST and CANDELS programs have provided WFC3 and ACS spectroscopy and
photometry over ~900 square arcminutes in five fields: AEGIS, COSMOS,
GOODS-North, GOODS-South, and the UKIDSS UDS field. All these fields have a
wealth of publicly available imaging datasets in addition to the HST data,
which makes it possible to construct the spectral energy distributions (SEDs)
of objects over a wide wavelength range. In this paper we describe a
photometric analysis of the CANDELS and 3D-HST HST imaging and the ancillary
imaging data at wavelengths 0.3um to 8um. Objects were selected in the WFC3
near-IR bands, and their SEDs were determined by carefully taking the effects
of the point spread function in each observation into account. A total of 147
distinct imaging datasets were used in the analysis. The photometry is made
available in the form of six catalogs: one for each field, as well as a master
catalog containing all objects in the entire survey. We also provide derived
data products: photometric redshifts, determined with the EAZY code, and
stellar population parameters determined with the FAST code. We make all the
imaging data that were used in the analysis available, including our reductions
of the WFC3 imaging in all five fields. 3D-HST is a spectroscopic survey with
the WFC3 and ACS grisms, and the photometric catalogs presented here constitute
a necessary first step in the analysis of these grism data. All the data
presented in this paper are available through the 3D-HST website.
