Sexing chicks?

[angelicflamesva]

I am completely new to having chicks & we have 30 that are 19 days old...8 are supposed to be sexed as all females & 1 male, the rest are a straight run...can yall help us figure out which ones are roos? The first 5 are all Light Sussex & they all look the same to me...

 

[angelicflamesva]

These are the two Black Sumatras, they are supposed to be a male & a female but which one is which?

 

[angelicflamesva]

And here are the rest...any ideas?
Sorry if the pics aren't much help...please let me know any advise on how to take pics that will show what sex they are!

 

[Marankindaguy]

On the two black sumatras I think the top one is the rooster because of the feather growth on the wings I think I read that hens feather out quicker on the wing as chicks