Canon 450D SLR camera, 18-55mm lens how to shoot the virtual background of M file? And must cooperate indoors (Opel 420 photographic lamp)?

Blur the background, use a large aperture, and you use almost the smallest aperture.

The aperture of the hood is indeed limited, so first, it should be placed at the 55th end with the largest aperture, second, it should be as close as possible, and third, the subject should be as far away from the background as possible.

When the flash is turned on, there is no way to open the aperture due to the limitation of synchronous shutter speed. At this time, it is necessary to take a little rustic approach, cover the flash a little, or equip the lens with a medium gray mirror.

If you shoot a still life, it depends on how big it is. Ordinary things don't matter. If something is small, such as jewelry, you'd better buy a macro lens. Canon's Budweiser and 180 micro-single, Longteng's SP90 and Sigma's 105 micro-single are all good. 50 microns is not recommended, because it is too close, just need to cooperate with the ring flash.

Is it too violent? If it is too violent, it is the problem of shutter speed synchronization. Your synchronous shutter speed is very low, so the aperture must be narrowed very small. So I suggest you cover the flash properly, or buy a medium gray mirror to filter it, which can reduce the light intensity and enlarge the shutter.