If you've visited a museum in the last five years, you've seen it. Maybe you've even done it — taken a picture of yourself with a piece of art. Perhaps it's because you love the painting or sculpture, or maybe someone in a painting looked like you (I've done this), or maybe it was just a famous piece of art and you wanted to share with the world that you'd seen it in person.

Depending on the museum you were in, taking selfies with the art may or may not have been allowed. Sometimes it can be hard to tell, so my advice is always ask if you're unsure. It's just respectful to do so.

The reason is that policies regarding photography vary. Some institutions have pieces loaned to them that aren't allowed to be photographed per the owner's wishes, like most of the rotating exhibits at The Tate in London. Others are concerned about what camera flashes will do to the art; bright lights can degrade certain paints and finishes. Some want to preserve a certain atmosphere: Sir John Soane's Museum, a small establishment that's housed in a Victorian townhouse in London, states on its website that it bans photography to "maintain the unique, magical atmosphere inside." There are areas of the museum with such tight spaces they even require personal items to be carried in clear plastic bags.

For other museums, the "no photography" rule is based on observed behavior that seems to fly against the idea of what the museum is for: "Personally, what I've noticed is that people spend more time taking pictures than looking at pieces of art," Benoit Parayre, the director of communications at the Centre Pompidou in Paris, told Bloomberg. "They take a picture, and don't even stop in front of the paintings and discover it."

For other places, it's purely practical: People taking selfies are more concerned with getting their shot than paying attention to where their bodies are, and can damage the art. This isn't just a baseless worry, it's happened. (See the video above if you need proof.) That's why some museums have certain areas where photographs are allowed. The Frick Collection in New York City allows photography in the Garden Court but nowhere else. That's because, "We tried a more open photo policy, but noticed how often visitors were spotted nearly backing into objects," Heidi Rosenau, the Frick's communication director, told Bloomberg.

But other museums have banned photography for logistical reasons. In a busy museum, people taking photos with the art causes traffic-flow issues. Or, to put it less nicely, people make nuisances of themselves, preventing people from looking at the art itself in the quest for the perfect pic. Sure, some people only take a quick shot, but we all have a friend or two who spends minutes getting the "perfect" photo — now just imagine them in a museum blocking people from seeing famous works of art that they've spent time and money to come see.

It's true — sometimes a selfie can be fun and harmless, but it can also be rude and get in the way of other people's experiences.

Some museums embrace selfies, and the social-media sites they inevitably end up on. After all, it's free PR for the museum. Both the Metropolitan Museum of Art in NYC and San Francisco's Museum of Modern Art allow photography. (And from personal experience I can say that both institutions have plenty of vociferous human guards keeping a very close eye on stupid behavior as well.)

If you really want to capture a moment in a museum, I'd suggest taking a notebook or sketchpad along. Choose one piece of art, find a place that's out of the way of other visitors, and commit it to paper — you can try for a copy, or you can just sketch your impressions. You don't need to be an artist to sketch (as you can see from my example below!), and it can be a wonderful way to truly capture your visit to a museum.

A sketch of a painting at the Met in Starre Vartan's notebook. I made this drawing at The Metropolitan Museum in New York during my last visit there. It's called 'Evening: Landscape with an Aqueduct' and shows Roman ruins in the Italian countryside painted by Theodore Gericault in 1818, and even though mine is a poor copy in one color, I remember this painting extremely well nine months later — way better than a selfie experience. (Photo: Starre Vartan)

Starre Vartan ( @ecochickie ) covers conscious consumption, health and science as she travels the world exploring new cultures and ideas.

Selfies at the museum: Thumbs up or down?
Museums are struggling to deal with the cultural issue of allowing people to take selfies with a piece of art.