When shooting night view of city
you must prepare four kinds of things usually
4. Black Card
The black card is mainly used to balance the light
When conditions in high-contrast
Need to balance the light with a black card
the situation of the picture
the light is the picture
the light of left building site need about 2s is F22 but the light of right site (tall building ) need about 30s is F22. how to have the two building in a picture at the same time (do not use the photoshop at home...)?? the all the Exposure 30s and F22 so you need a black card to cover left site about 28 seconds and you must shake the black card to Avoid to with a black line in the edge of card then you will get the picture.
and go take picture...enjoy that~~~
the other picture with using black card
you can link the youtube ...but the langeage is chinese...