[Sascha Engel] “An EX3 is so much more expansive in rent/buying – will it be worth the difference?”
That’s a call only you can make. The DVX 100b was, I think, the top of the line of prosumer SD video. You write you have the DVX100 so I am guessing you do not have a model A or B, which had significant upgrades. Still, an excellent SD camera.
An HDV camera such as the EX1 or 3 or one of the Panasonic P2 cameras will produce significantly better images — more visual information, smoother gradations from pure white to pure black, more exposure range, etc. It’s your money.
If this is your first time out with such a project, maybe the place to put the money is with sound: hire a good sound person who knows well how to use and place a good mic on a boom and who can also finesse radio mics. As Richard noted, good audio is essential to a dialogue-intensive project.
And then you can concentrate on the actors’ performances. How good your script is, and how well the actors perform, and how cleanly we understand their words trump any visual fine tuning. And I say that as a lifelong director of photography.
Rick Wise
director of photography
San Francisco Bay Area
and part-time instructor lighting and camera
grad school, SF Academy of Art University/Film and Video
https://www.RickWiseDP.com
https://www.linkedin.com/in/rwise
email: Rick@RickWiseDP.com