What happened to change the children's perceptions of their father and how did they change?
When Scout first describes her father, she calls him “satisfactory” because “he played with us, read to us, and treated us with courteous detachment” (ch 1). Atticus is not the only one who shows detachment. Scout and Jem call their father Atticus, not Dad or Father.
In chapter 10, Scout describes her father as old and “feeble” and points out that he is nearly 50. She even asks Calpurnia why he can’t do anything. The Finch children do not believe that their father can do the things other people do, like play sports with them. They don’t seem to find being a lawyer very interesting. In fact, Scout says, “our father didn’t do anything” (ch 10). He also wears glasses and is described as being “nearly blind in his left eye” (ch 10), so Scout does not seem to have much hope for him.
It is no coincidence that all of these weaknesses of Atticus are described in this chapter. This is when Atticus shoots the rabid dog, and the first time his children are proud of him. He turns out to be a crack shot; just because he doesn’t like guns doesn’t mean he isn’t able to use one. His children are dumbfounded, and finally proud.
The other incidents that change the children’s perceptions of Atticus surround mental strength, rather than physical. They realize how hard Atticus’s job is, and how much moral courage he has. They begin to respect him for his choices, not for his ability to play tackle football or shoot a gun.