In-Universe:
The U.S.S. Defiant slower enters the plasma fields of the Badlands.
Production:
An aft, dorsal views of the studio model as it slowly moves forward.
"The rolls and thrusters bursts Dax announced were brought to life by Gary Hutzel's crisp motion control photography of the Defiant and DS9."
— Cinefantastique Volume 29, Numbers 6/7 (Page 45)
Gary Hutzel ditched the CGI Badlands effect from Voyager and created an all new one.
— Star Trek DS9 Companion (pg 420)
