quick search turned this up:
Using a different lens won’t make much difference to the DOF on an EX3 because it’s the camera and not the lens that’s the limiting factor. Image sensor size plays a huge part in narrowing the DOF along with iris position and the amount of zoom used. The larger the imager the more narrow the depth of field can be dialled in. Also, the wider the iris opening the better (lower F stop number). And as you’ve pointed out the farther away from the background the talent is the better.
The EX3’s 1/2″ sensors are going to need some help from you setting up the camera to get the most out of the desired shallow DOF.
Open the iris to F1.8 and then adjust the lighting to get proper exposure i.e. using less light.
If shooting in daylight then use the camera’s ND filters to cut down the amount of light entering the lens.
Increasing shutter speed also cuts the light amount because there’s less time for the it to hit the sensors.
Move back as far as you can from the talent and then zoom in to frame the head/shoulders shot. Iris as wide as possible then do a manual focus. See how that works. It’s tough getting a shallow DOF with 1/2″ imagers, especially when space between talent and camera is limited.
– Don
Don Greening
A Vancouver Video Production Company
Reeltime Videoworks