How does Canon 70D shoot the starry sky?

The original battery is full, tripod, pay-off, clear sky, use door B, pay attention to the prospect. Supplement: 1. Choose a clear moonless and cloudless night sky. 2. It is best to be in the suburbs where there is no stray light. 3. Bring tents, dry food, flashlights and other outdoor necessary equipment. 4. The camera is fixed on a tripod, the ISO is set to 100, the focal length is set to infinity, the aperture is set to 4-8, and the shutter is set to door B (and the lock needs to be released with a cable). 5. Aim the lens at the starry sky, open the lens cover and press the shutter (lock). 6. get into the tent, eat some dry food and drink some water, and wait quietly for the time to pass. 7. Look at the time. 8. Open the camera preview to see if the photos are satisfactory. It should be a perfect star orbit photo. 9. If it is too dark, you need to extend the waiting time if you shoot again, otherwise you need to shorten the time.