  We present photometry of the exoplanet host star TrES-3 spanning six
occultations (secondary eclipses) of its giant planet. No flux decrements were
detected, leading to 99%-confidence upper limits on the planet-to-star flux
ratio of 0.00024, 0.0005, and 0.00086 in the i, z, and R bands respectively.
The corresponding upper limits on the planet's geometric albedo are 0.30, 0.62,
and 1.07. The upper limit in the i band rules out the presence of highly
reflective clouds, and is only a factor of 2-3 above the predicted level of
thermal radiation from the planet.
