i-TTL keeps on doing its excellent job to balance the light even with direct flash with its head straight forward and dome.

The ribbed dome diffuses the light plenty but, still not what you may want to do for a close-up portrait.

With the flash head with dome at 60 degrees, the very apparent shadows in the previous shot fade a bit although not that much; contrast decreases.

Too hot at the top for a shot at this distance. Not recommended.

Light is much better when bouncing from the ceiling straight upwards at 90 degrees with the dome on.

Comments

Using the dome improves the quality of the resulting image when at close and medium ranges. For long distances you will do better with the dome off.