Citoyenne la traductrice jacobine

So I finally got the letter from that Jamet book--of course, I'm not endorsing it, since the author hates Robespierre enough to portray him as a paedophile and a child-murderer, among other things. That said, the letter "he" "gave" to Camille when they were at Louis-le-Grand (in the book, of course): 


Ahem. 

Also, I was wondering if anyone could enlighten me as to how screencaps are taken; does one need special software or equipment, and just how is it done in general?