Observation Four - Craters at 4 days old with Binoculars August 10

The most favorable time for viewing this crater named Petavius is through a telescope when the Moon is only four days old. This is upside down in the telescope.  

Earlier, on the third day the crater is nearly devoid of a shadow.

http://www.astrosurf.com/cidadao/moon_obs.htm

This why we observe the moon on different days.  
The shadows we see are at different lengths.  

Moon at 4 days old.
Craters with binoculars:

Vendelinus 
Petavius
Cleomedes
Atlas
Hercules
Endymion
Macrobius