Ask the masters how these two photos were taken and post-produced. My star's orbit didn't turn round. Why does the first picture look like a galaxy?

1, site selection, away from urban areas and light pollution.

2, time selection: two hours after sunset, two hours before sunrise, it is best to avoid the moonlight, the full moon can not be photographed, you can shoot a few days before and after the first day.

3, weather choice: transparent, cloudless is the best.

4, equipment selection: the best is super wide angle (such as 24mm), large aperture, high sensitivity. Timing cable release, preferably wired, stable operation.

Main equipment settings:

5. Aperture: The aperture can be as large as possible to absorb more light, which can also present darker stars. After the aperture is reduced, the orbits of stars are scarce.

6.ISO: Set the maximum acceptable ISO value to absorb more light. For the same reason.

The first galaxy:

7. exposure combination: use the maximum aperture, high sensitivity (such as ISO3200, so the camera is required to be a little better), and the exposure time should not exceed 30 seconds, otherwise the star trajectory will be taken.

The second star track:

8. If you want to shoot the effect of stars circling, it is easier to use a wide-angle lens as long as Polaris is included in the composition range.

9. Example of exposure combination: ISO 100, aperture F2.8 and exposure time 15 minutes are basically normal under the illumination of the first quarter moon or the second quarter moon, and exposure will last for 30 minutes until F4. If there is more than half a month before the full moon, the aperture can only be reduced to F8 exposure time 15-30 minutes, so that the foreground will not be overexposed, but the number of exposed stars is obviously more than that of in.

Exposure time affects the length of a star's orbit. In order to avoid too long exposure time, superposition method can be used, that is, a single photo with high sensitivity and large aperture can be used to realize more and brighter stars, and then hundreds of films can be superimposed to realize magnificent star orbits.

Noise reduction function:

10, it is suggested to turn on the internal noise reduction function. Although it takes time, if you don't turn on the internal noise reduction, many details will be lost in the post-processing noise reduction, and you can't stand it.