A Baltimore Sun photographer who took a buyout, started a blog, and changed the photography business forever.

Hobby notes that while amateurs have certainly taken business away from professionals, "if you look at them the other way, they're also a really big market" for further instruction.

Others have taken notice. Since Strobist's launch in 2006, various photographers have taken up the task of bringing knowledge to amateurs, most prominently on the blog DIY Photography, now a full-time position for the site's proprietor, who quit his job as an engineer. Dozens of other photographers maintain smaller-scale blogs or post tutorials for DIY projects on Instructables.

McNally, one of photography's premier names, agrees. The longtime photographer for Life and National Geographic is now a blogger and the author of several books about lighting with small flashes. That a true star of the photography world is now sharing lessons learned at Gil Bensimon's feet on a blog and is sharing billing on a tour with Hobby is indicative of how flattened the hierarchy of photography has become.

McNally doesn't see anything demeaning in sharing his insights with thousands of amateurs; rather, he says he's come to enjoy teaching. "If you encounter passion, you have to counter it with your own passion," he says. "Even if, at the end of the day, you feel they're not going to go out the next day and climb the Empire State Building."

That sentiment is alien to the old guard in the professional photography world, where, Hobby says, "there's a lot of information-hoarding, and [a sense that] if I teach this person how to do this, he'll become my competition." Once the dust settles from all the change he's helped bring about, Hobby thinks there will still be legitimate careers for professional photographers. "You'll have fewer rock stars, and a much larger middle class," he says, a group of photographers who will find ways to distinguish themselves from the rest of the pack.

Click here to launch a slide show of David Hobby's photos.

Correction, April 27, 2011: This article originally stated that David Hobby's cross-country tour was sold out. It was not. (Return to the corrected sentence.)