Because less light reaches your camera’s sensor when using a large lens (or a spotting-scope, in this case) your camera will need to be adjusted to compensate. The table below shows the effect of various shutter speed and ISO settings on the brightness of the picture.These settings can be adjusted by setting your camera to “Manual”. Refer to the camera’s instruction manual for further details.All pictures were taken at dusk, using a Canon EOS Rebel T3 mounted on a 20-60x80mm spotting scope.For a PDF of this and other direct project digiscoping tips get the Direct Projection Digiscoping Tips guide.