Sundog is an atmospheric optical phenomenon. They are commonly caused by the refraction and scattering of light from plate-shaped hexagonal ice crystals either suspended in high and cold cirrus or cirrostratus clouds.
This composition photo mainly shows the relationship between the position of the sundog and the sun altitude. The simulated sundog picture is taken from the webpage: https://www.atoptics.co.uk/halo/dogalt.htm, and the corresponding actual photos are the sundog photos taken by me over the years.
When the sun is low, the sundog almost coincides with the position of the 22-degree halo, but as the sun's altitude increases, the position of the sundog will gradually deviate from the position of the 22-degree halo. At solar elevations much above 40° they are difficult to discern.
Sun dogs are best seen and most conspicuous when the Sun is near the horizon. When the sun gets higher and higher, the color of the sundogs is close to white and they look like 2 little sun virtual images on both sides of the sun.
More instructions and photos are as follows: https://www.facebook.com/groups/100680376948050/permalink/1483534238662650/

Canon EOS 6D + Tamron SP 24-70mm F2.8 Lens

Use PowerPoint to compare the simulated photos of the sundog with the actual photos.