Setting up for products with transparent background

[superreggie]

I'm a designer who often uses product shots. years ago I received a set of product shots, top down, of cosmetics, and it was already masked so that it had a transparent background. There were transparent plastic items (imagine a glass bowl, a clear plastic container) and shadows, but the files had a transparent background so that I could place the image on any background in photoshop and it would look totally natural.

I know some techniques to treat an image after the fact to make it work this way, but how can you set up the shots in advance? Is this simply a green screen?
thanks

 

[table1349]

Pretty much yes. The screen color is determined by the product color.

 

[epatsellis]

Pretty much yes. The screen color is determined by the product color.

Or, better yet, properly lit, exposed and an alpha channel drawn or created that drops the background. It's not that hard to shoot high key and drop a 255 background. Keying has it's applications, but this isn't really one that works well without a lot of work.

 

[Scatterbrained]

Pretty much yes. The screen color is determined by the product color.

Or, better yet, properly lit, exposed and an alpha channel drawn or created that drops the background. It's not that hard to shoot high key and drop a 255 background. Keying has it's applications, but this isn't really one that works well without a lot of work.

This. ^ Shoot it on white. Done right you can get the white background to be a smooth 255 in camera, after which created the alpha channel is pretty straight forward. Chromakey works great for banging out dozens of prom photos where they are supposed to be standing in some elegant castle rather than a dingy high school gym, but for products it creates more work than just getting the background right in camera.