In order to be able to determine the field of view of your imaging device, you will need to find out two things:
1. The size of the sensor of the chip (in millimeters)
2. The focal length of the telescope that you have (in inches)
Take the two and use this formula: (135.3x D) / L. This will give you the field of view (in arcminutes) for your telescope and imaging device.
Where D is the size of the Chip, L is the focal length of your telescope.
For example, a Nightscape 8300 has a sensor size of 22.5mm (D). If you use it with an 11-inch Celestron EdgeHD, which gives you a focal length of 110.24 inches, the formula becomes:
(135.3 x 22.5)/110.24= 21.62 arcminutes
Therefore, using a Nightscape 8300 with an 11-inch EdgeHD yields a field of view of 21.62 arc minutes.