For normal travel, it’s usually fine—and often preferable—to carry the camera with the lens attached. That keeps the setup ready to use and reduces how often you remove the lens, which helps minimize dust getting into the camera body.

If the camera will be exposed to unusually rough handling, separating the body and lens and padding each piece can offer extra protection.

If you add more lenses, a flash, or other accessories, a dedicated camera bag or backpack with padded compartments is the best solution. These bags keep gear organized, protected, and easy to access while moving around.

In short: lens attached is generally best for everyday transport; remove it only when needed for space or for extra protection in rough conditions.