On this point the author apparently did not read Earth Not a Globe which explains why this occurs. We have a writeup in our Wiki: https://wiki.tfes.org/Magnification_of_the_Sun_at_Sunset
The article was written by real descendant of "Dr" Rowbotham and successor of his "science".
First part is hope that reader will not understand the difference between sharp view of the light source itself, and surrounding camera glare.
Second part uses description of divergence of laser or light beam, as if eye is big enough to receive the whole beam at observing point.
How can configuration of Sun spots remain the same in "projection" with just direct beam, without set of lenses to project the image?
Ever seen a movie or slide projector?
If you focus camera well and set short enough exposure, or add filter, you will see the real size of the light source, not the glare blur around it.
If you get cheap welding mask from Lowe's and a calliper,
you can see and measure the Sun itself, not the glare around it.
In that case calliper will show you constant size (angular diameter) of the Sun through the day, not of the glare around it.
Moon has light just faint enough to see her that way without filter.
Through the night Moon keeps the constant apparent size as well.
Moon image is also detailed in "projection" without set of lenses.
Of course, there are more precise instruments, if you have access.
Some other FE sources are not talking about dispersed light, but air magnification.
(How convenient. If someone starts talking about one explanation, then we point out the other one.)
How high is required refraction index of air, and why such air doesn't magnify airplanes and balloons.
Sun is at 3000 miles above the ground, and 99% of the air is up to 30 miles high.
(Air density measured and confirmed no matter who did it, Flat Earther or Globe Earther.)
High-altitude balloons are unmanned balloons, usually filled with helium or hydrogen and rarely methane,
that are released into the stratosphere, generally attaining between 18,000 to 37,000 metres (59,000 to 121,000 ft;
11 to 23 mi). In 2002, a balloon named BU60-1 attained 53.0 km (32.9 mi; 173,900 ft).
Above that the molecules are too far from each other to have any noticeable optical effect.
Why air shows magnification effect on Sun and Moon and not on anything else, especially objects 100 or more miles away?
And I'm not talking about glare blur around.