Photographing the December 21st “Christmas Star” or conjunction of Jupiter and Saturn is simple pinpoint star photography. Settings on your camera are the same as you’d use when photographing any pinpoint stars.
I’m planning on the 24-105mm lens at 105mm because I’d like a little foreground but enough magnification to get the . I’ll have my bigger lens just in case. That would be my 100-500mm.
I’ll use a wide open aperture of f/4 or f/2.8. At 105mm the shutter speed would be 4 seconds. At 400mm it would be a 1 second shutter speed.
Compose the scene and focus on infinity or the planets if your camera will do that. Turn off auto focus and image stabilization.
Put the camera in the manual exposure mode. Set f/stop to wide open, set shutter speed based on the formula below, and raise the ISO to balance the light meter.
The shutter speed depends on the lens you use. The formula is 500/mm of the lens. Cropped sensor is 500/(mm of lens X crop factor). Do the math but remember to do the math inside the parentheses first.
Camera has to be on a tripod, of course. A shutter release helps get a steady shot.