Taking a photo of a visual work is making a reproduction of it—which means copyright alw gets involved—but that’s not all it is. Other laws might apply, too.
As a general rule, when you are lawfully in a public space, you have the right to photograph anything in plain sight, even if what you see is private property. If you’re on private property, such as a private museum or a gallery, then your right to photograph anything you see is subject to the property owner’s permission.
As for copyright, though, that comes into play with respect to the subject of your photography. Street art presents a case where a work might have copyright protections, but is also plainly visible from public spaces. Taking a picture of the work means you’ve created a reproduction, one of the acts covered by copyright law. If you take a photograph of just the artwork, and then attempt to sell prints of the photo, the artist has an excellent claim against you. But what if you use the photo for personal use only? Although it’s unlikely that there will be someone to stop you from taking the photograph, or using the photograph for personal use, like printing it and framing it for your wall, or using it as a desktop wallpaper on your computer, that’s still a technical violation of the law.
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