Aerial Perspective

I was asked the other day about aerial perspective. Well for the sake of those that don't know
(and I am sure there are many who read this understand the phenomenon well) here is a simple version.

The atmosphere is not clear it contains,"stuff" particles dust etc... The greater the distance viewed the more stuff you look through. Hence subjects close by are in focus sharp and have plenty of local colour. The further away they are the more out of focus they appear and the less contrast and colour there is. Similarly if you look at a celestial object such as the moon it is always clearer directly overhead as opposed to the horizon as you are looking through less of the earth's atmosphere.
As stated colours and contrasts are therefore reduced in distant subjects. Generally they appear more blue, but if the light conditions change they may take on those colours such as at sunrise..
You will note that in the painting of "Newport in the early morning" above the distant hills are a blue and purple and have little contrast. It is important to use aerial perspective to get the feeling of depth /distance in a landscape.

Today we have two of the grandchildren so little time for painting.

Link Blue Ridge Mountains