All footage of Ecliptor and Darkonda outside of the Dark Fortress is new footage which includes all of the footage of Darkonda and Red Ranger fighting as well as the footage of Ecliptor spying on their fight.
Heres' Ecliptor and Astronema.
This shot is new footage, this is when it starts.
As soon as the 5 Rangers appear on Earth, it's still new footage.
Here's new footage of Batterax.
Here's Astronema and Ecliptor.
All footage of the Red Ranger riding his Galaxy Glider while trying to catch up to Darkonda is new footage.
The footage of Batterax "growing" (even though we don't actually see him "growing" is new footage. Here's a shot of him as a Giant even though the Satellasers are still firing on him.
All following shots of the Rangers on the ground is new footage which includes the shots of them calling for Astro Megazord power.
Once the Astro Megazord appears, all of the Giant footage is Sentai footage.
Here's Darkonda and Dark Specter.

Following info comes from Mega 9.
Here's Ecliptor but in his 2nd form.    
Ecliptor's new powers were too much for him at first so he couldn't fight away in his new body.
Here's Batterax.  
Lady Blue is capable of disguisng herself as a human.
Here's some more Batterax shots.      
In Megaranger, Batterax emitted sound waves into CDs so that whenever a human listened to them they would have the urge to commit a violent act. Saeko, a friend of Kenta's had discovered the CDs' evil sound waves so she tried to collect as many as humanly possible even if it meant shoplifting. When Lady Blue discovered Saeko was on to them, she sent Batterax to deal with her. Saeko was about to kill herself when Chisato intervened and then Batterax ordered Saeko to kill her.
Heres' a shot of Saeko strangling Chisato.
Here's Giant Batterax.  
Here's a shot of the Astro Megazord firing its Blaster. It has its Saber in the other hand.