Using Live View on the Canon 40D at the prime focus of a Tak Mewlon 180 F12 (a somewhat “slow” ‘scope) I was able to easily see and focus on 3 of the 4 bright stars in the Trapezium reasonably easily.
A = 5.13 mag
B = 6.35 mag
C = 7.2 mag
D = 7.49 mag
Cheers
Dennis
EDIT:
Here is a
link to some "Remote Live View" screen captures. All 4 stars in the Trapezium can easily be seen, as can Rigel's fainter mag 10.4 companion.