  Ground-based exoplanet surveys such as SuperWASP, HATNet and KELT have
discovered close to two hundred transiting extrasolar planets in the past
several years. The strategy of these surveys is to look at a large field of
view and measure the brightnesses of its bright stars to around half a percent
per point precision, which is adequate for detecting hot Jupiters. Typically,
these surveys use CCD detectors to achieve high precision photometry. These
CCDs, however, are expensive relative to other consumer-grade optical imaging
devices, such as digital single-lens reflex cameras (DSLRs). We look at the
possibility of using a digital single-lens reflex camera for precision
photometry. Specifically, we used a Canon EOS 60D camera that records light in
3 colors simultaneously. The DSLR was integrated into the HATNet survey and
collected observations for a month, after which photometry was extracted for
6600 stars in a selected stellar field. We found that the DSLR achieves a
best-case median absolute deviation (MAD) of 4.6 mmag per 180 s exposure when
the DSLR color channels are combined, and 1000 stars are measured to better
than 10 mmag (1%). Also, we achieve 10\,mmag or better photometry in the
individual colors. This is good enough to detect transiting hot Jupiters. We
performed a candidate search on all stars and found four candidates, one of
which is KELT-3b, the only known transiting hot Jupiter in our selected field.
We conclude that the Canon 60D is a cheap, lightweight device capable of useful
photometry in multiple colors.
