In photography, a distinction is made between ‘halation’ and ‘flare’. Both cause spreading of light into areas of the image that should be dark.
In film days, ‘halation’ arose from scattering of light within the material of the film itself. Many films had an ‘anti-halation’ backing (matt black) to minimise the problem In digital photography, this is less of a problem, although some reflections can occur between the micro-lenses that are placed above each photo-sensor on the image chip.
On the other hand, ‘flare’ is created by light scattering amongst the glass elements of the lens. Most photographic lenses are made up from several separate glass ‘elements’. Some light is reflected from the surface of each element and can then be reflected to and fro within the lens, where it causes a hazy-looking image. Modern lens coatings are designed to reduce reflection as much as possible, to minimise this effect.
Most of your examples show ‘flare’ rather than ‘halation’, although the end result looks similar.
Thank you so much,Mike.That is very useful to know and I am sure other people, too ,will benefit.I had never come across the word before.I confess I learn backwards by trying it then learning theory later.It’s good to know some basic notions.
How my heart sings 
In photography, a distinction is made between ‘halation’ and ‘flare’. Both cause spreading of light into areas of the image that should be dark.
In film days, ‘halation’ arose from scattering of light within the material of the film itself. Many films had an ‘anti-halation’ backing (matt black) to minimise the problem In digital photography, this is less of a problem, although some reflections can occur between the micro-lenses that are placed above each photo-sensor on the image chip.
On the other hand, ‘flare’ is created by light scattering amongst the glass elements of the lens. Most photographic lenses are made up from several separate glass ‘elements’. Some light is reflected from the surface of each element and can then be reflected to and fro within the lens, where it causes a hazy-looking image. Modern lens coatings are designed to reduce reflection as much as possible, to minimise this effect.
Most of your examples show ‘flare’ rather than ‘halation’, although the end result looks similar.
Thank you so much,Mike.That is very useful to know and I am sure other people, too ,will benefit.I had never come across the word before.I confess I learn backwards by trying it then learning theory later.It’s good to know some basic notions.