My set-up for capturing images thru binoculars.
The exit pupil (diameter of the light leaving the eyepiece) is only 6mm. With a small sensor camera, this covers a large area of the image sensor. If I were to use a larger format camera (e. g. APS-C), less then 10% of the sensor is utilized. This is why you can get very fine detail Lunar images thru an eyepiece using your cell phone's camera!
The camera I use for celestial binocular shots is the same one I use for street photography.

Canon G9X, 11 X 70 Binoculars