AUSTIN, Texas -- Amid the lights, video boards, shooting sparklers and other elaborate props that are commonplace on stage at a rock concert stands a quiet and very tall figure, dressed in blue jeans and an unassuming T-shirt, holding a camera.

He needs to be close to action, but he also has to stay out of the way of the main attraction, all the while capturing the poignant moments that will eventually document this particular moment in the band's history.

• Enter the "RUSH Off To Chicago" sweepstakes

He slithers on the ground like a snake, looking for the perfect shot. He does this while remaining relatively unnoticed by more than 13,000 fans who have gathered at this Austin amphitheater, site of yet another performance by the legendary band Rush, currently on tour and celebrating its 40th year together.

Video: Baseball, music royalty forged lasting friendship

Why are we talking about the band's photographer? Well, for one, he's about a foot taller than an average-sized man, making it a little extra challenging to be invisible.

And he happens to be one of the greatest left-handed pitchers in Major League history. He's Randy Johnson, a veteran of 22 Major League seasons, winner of five Cy Young Awards, member of the newest Hall of Fame class that will be inducted into Cooperstown on July 26 … and a professional photographer.

"I've learned how to be a 6-foot-10 ninja," Johnson said a couple hours before Rush began its nearly three-hour set.

Johnson will shoot several Rush concerts in the coming months, and fans can enter for a chance to win a VIP weekend with Rush and Johnson in Chicago, which features tickets to a Rush concert, a Cubs game, and the chance to meet two Hall of Famers: Johnson and the band.

Video: Respective hobbies brought Johnson and Lee together

He's worked their concerts in the past, too, thanks in large part to his long-standing friendship with the band, which is comprised of lead vocalist, bassist and keyboardist Geddy Lee, drummer Neil Peart and guitarist Alex Lifeson. Johnson is particularly close with Lee, whom he first met more than 20 years ago at a Rush concert in Seattle, Johnson's home for 10 years of his career.

"A mutual friend called and said Randy would love to come down to the show," Lee said. "I remember very clearly talking to him. We stayed in touch from there."

Hall of Fame friends

But this isn't just a typical friendship between two famous people. We hear plenty about musicians and athletes meeting each other, hanging out a bit and establishing some sort of love-you-man camaraderie not uncommon among people who come from high-profile industries.

This is a little different. Johnson and Lee are more like kindred spirits. They're two men who have a genuine, thoughtful respect for one another, and who have a passion for each other's chosen vocation that goes beyond normal fandom. An extensive compilation of "On Their Game" with Johnson and Lee will air in the days ahead.

Video: Lots of common ground for athletes and musicians

Lee is a passionate baseball fan and avid memorabilia collector. His personal collection, in Johnson's estimation, is as impressive as any you'll find outside of Cooperstown. Lee's memorabilia room is filled with hundreds of autographed baseballs (including Cy Young, Walter Johnson and Christy Mathewson) and bats used by historic players (featuring one used by Shoeless Joe Jackson), as well as books, programs and other items that tell the story of baseball history.

Johnson's music room at his home in Phoenix is equally impressive.

"I was completely blown away by the level of his knowledge of rock music," Lee said. "He has an incredible sound system, a really amazing turntable sound system. He showed me his record collection. I've never seen anything like it."

And they both share one other hobby -- photography.

Rock and Roll photos

As a student at USC in the early 1980s, Johnson majored in photojournalism and would have pursued that as a profession, if not for that electric left arm that allowed for him to throw a baseball 100 mph.

The Big Unit worked for a couple of small magazines in Los Angeles and for his school newspaper.

"I usually got the assignments to cover the concerts because nobody else wanted to," Johnson said. "That was right up my alley. I got to see pretty amazing concerts back in the early '80s in college."

His Major League career didn't end until he was 45 years old. It took him almost no time following his retirement in 2009 to pick right up where he left off and delve full force into photography.

Video: Hall of Famer Lee discusses likely call for Johnson

Johnson has traveled the world. He's been on African safaris and USO tours. He's been to Rwanda, Turkey and London. He's shot motor sports and concerts.

"To bring my camera on all these trips and see how other parts of the world live is pretty breathtaking," Johnson said. "To be able to document that through my photography is exciting for me. Then I got to the point where I wanted to share it."

• Big Unit photographs Rush

He developed a website to show off his best photos. Of all of his subjects, music is Johnson's biggest passion, and he found a perfect partner in Lee, who developed an interest baseball as a youngster and became obsessed with the sport as an adult.

The life of a rock musician entails a lot of late nights working, then mornings spent ordering room service in the hotel. There are limited choices on hotel TVs, and back in the day, Lee's options were soap operas and Cubs games. Lee chose the latter, and before long, he was hooked.

"I really got into it and fell in love with it all over again like when I was a kid," Lee said. "Being a nerd that I am, I couldn't avoid the love of stats. I learned how to score the games and basically became a nut for the game."

When Johnson and Lee get together, Johnson wants to talk music and Lee wants to talk baseball. They manage to squeeze in time for both. They've also talked Hall of Fame speeches. Lee made his with Rush at The Rock and Roll Hall of Fame and Museum inductions in 2013, and Johnson is working on his Cooperstown speech now.

Lee, chuckling, described their friendship as "a mutual appreciation society."

"One of the things I've always admired about Randy is the thoughtful and intelligent approach he always took to his game," he said. "Always looking for an edge, always looking for a way to be better at what he did on the mound. The way he talked about being accountable. You don't hear a lot of athletes talk about being accountable. I found that inspiring. I took away from that something that I could apply to my own profession."

Video: Behind-the-scenes look at concert setup, photography

Johnson, who works for the D-backs as a special assistant and spends most of his time in that job tutoring Minor League pitchers, said he enjoys hearing stories of when Rush was just a young and untested band waiting for the big break.

"When I was young, I was kind of a free-willed person," Johnson said. "I just kind of got the ball and went out and pitched. There was more to it than that. I enjoyed hearing [Lee's] stories about when they were coming up, and they were warming up for some of the bands that are still out there performing to this day."

Rush's 40th anniversary tour continues through the summer, a frenetic schedule involving stops in 34 cities with concerts every two to three days. Johnson won't be at all of them, of course, but the shows he is working, he'll go through the motions largely unnoticed, even by the three band members who have been playing to packed houses since they began this journey as 20-year-olds decades ago.

But rest assured, Johnson does take time to appreciate the scene around him.

"I'm a friend first, but also a big fan," Johnson said. "I was a huge Rush fan before I met Geddy. To have known and become friends with them for over 20-some years and photograph them on various tours is a huge thrill for me."

That sentiment, clearly, is mutual.