I don't think "nerdily" is a real word or in the dictionary. In fact my computer just put a red line under it as I typed it. The speaker has done something common: he's manufactured a word on the spot by combining a real word with an understood suffix. "Nerd" itself is a new word. It means someone who loves technology and technical details, while being unskilled or inattentive socially. The writer has manufactured the word "nerdily," and it is an adverb meaning "to do something in the way nerds do it" or "to be interested in something in the way nerds are interested in it." For example, when they watch a movie most people are interested in the story and the acting; someone who is fascinated by the kinds of lenses they used, whether it was produced in Todd-AO or Cinerama, or the use of 70mm 5-perf film, is nerdily interested in it.

Nerd: "a single-minded expert in a particular technical field" (note that the connotation tends to be negative when calling someone else a nerd, but rather neutral when calling oneself a nerd) In this case, it's changed into an informal adverb form. It's similar to 'obsessively'.