I'm not shy about saying that I love practical effects so much more than digital. I great example of using digital effects correctly and incorrectly in a film is 2007's
I Am Legend. Digital effects, to me, are meant to enhance the visuals, but not be distracting to the point where they take you out of the believability of the scene. When the film is showcasing a desolate New York City, the digital effects are wonderful. It's as powerful as an abandoned London in Danny Boyle's masterpiece,
28 Days Later.
But in my opinion, director Francis Lawrence made a huge mistake when he chose to use digitally created Hemocytes, instead of practical. Anytime those infected creatures were front and center in the action I was taken out of the film. I felt like I was watching Roger Rabbit interacting with Bob Hoskins.
By the way
I Am Legend, is loosely based on Richard Matheson book. Which has been adapted to film twice before Will Smith's version,
Omega man with Charleton Heston and earlier
The Last Man On Earth with Vincent Price. Even after three films, none have captured the simple, but ingenious premise, that the last man on Earth represents Dracula, and the vampires (which they are in the book, but not always portrayed on film) are the humans. Matheson wanted you to see what it was like to be like Dracula, one of your kind, and feared by the rest of society. Like I said, simple but fascinating, and the execution is top notch.
"In December 1997, the project was called into question when the projected budget escalated to $108 million due to media and shareholder scrutiny of the studio in financing a big-budget film. Scott rewrote the script in an attempt to reduce the film's budget by $20 million, but in March 1998, the studio canceled the project due to continued budgetary concerns, and quite possibly to the box office disappointment of Scott's last three films, 1492: Conquest of Paradise, White Squall, and G.I. Jane. Likewise, Schwarzenegger's recent films at the time (Eraser and Warner Bros. own Batman & Robin) underperformed, and the studio's latest experiences with big budget sci-fi movies Sphere and The Postman were negative as well. In August 1998, director Rob Bowman was attached to the project, with Protosevich hired to write a third all-new draft, far more action-oriented than his previous versions, but the director (who reportedly wished for Nicolas Cage to play the lead) moved on to direct Reign of Fire and the project did not get off the ground." - Wikipedia
And now for a comparison. The first video below features the VFX breakdown of many of the key shots in Will Smith and Francis Lawrence's 2007 film
I Am Legend. Skip to the three minute mark to see the digital effects behind the making of the infected creatures in the film. While the second video is of a makeup test for a practical version of the creatures that was not used in the film. It was created by Hollywood special effects legend Steve Johnson. It's been posted before but for the context of the article I felt as though should be included.