Answer:
The easiest thing to do in you situation would be to use references from other drawings or real pictures, and make sure you use a consistent light source. Sorry if this doesn't answer you question but these are some tips.
La sirena come on man dont you have google translate
Before photography, visual arts was one of the only way to capture the world. Famous artists painted portraits of significant people and beautiful landscapes which are very time consuming. I would say photography in its early days is simply a realistic window to see the world and the people in it. The inventors of photography believed that photos are no longer drawn by hand, but "written by light".
An article on petapixel says: The use of cameras has allowed us to capture historical moments and reshape the way we see ourselves and the world around us.