A moment of full disclosure: This is not your father’s Sherlock Holmes. If you prefer the legendary detective in his traditional deerstalker cap and cloak spouting off soft-spoken observations from the sidelines, then this Guy Ritchie-directed version is not for you. But for anyone who appreciates a fresh, yet reverential, take on a classic story, then the new film starring Robert Downey Jr. as the astute sleuth is a film worthy of investigation.

From the opening minutes, “Sherlock Holmes” is noticeably more physical than any previous portrayal of the famous investigator. The adrenaline-fueled and action-packed, yet convoluted and clever, movie is as much of a change of pace for the character as it is for Ritchie — who is usually famous for films about the violent gangster underworld of modern London such as “Snatch” and “RocknRolla.” The overall balance of action and intellect and humor and sweetness brings welcome depth to the film.

In his first time directing a nonmodern-day story, Ritchie benefits from the more formal nature of the era to reign in his tendency toward madcap mayhem. The script, by Michael Robert Johnson, Anthony Peckham and Simon Kinberg, further guides the fine line “Sherlock Holmes” plays between the old and the new.  

The cast is led by the naturally charismatic Downey, who once again restarts his career, as he takes on a bit of his own personality in the film with speedy retorts to Watson’s grumbling and his flirtation with former flame Irene Adler (Rachel McAdams).

For all those accustomed to sidekick Watson playing second fiddle to Holmes, Jude Law is intelligent, equally handy in a fight and witty. Watson is merely a more stable version of Downey’s character.

The only weak link is Mark Strong as the villainous Lord Blackwood. What is meant to be unemotional menace comes off as monotone disinterest at times, and he never seems to throw Holmes off his game — the true test of a well-matched foe for the detective.

From the updated action-packed style to the quality and pure enjoyment of the acting, “Sherlock Holmes” feels as fresh as it was meant to.

“Sherlock Holmes” was written by Michael Robert Johnson, Anthony Peckham and Simon Kinberg and directed by Guy Ritchie.