Small Studio/Objects Containing White : Getting A Pure White Background

Question

This is a question that pops up occasionally, and I wanted to ask it a bit differently because this is an issue 1) that lots of people have; and 2) is a bit different from working with clearly defined objects.

The object:

• Work within the constraints of a small studio to shoot small objects
• Objects can, and probably will contain white components (see photo below)
• Isolate the subject against a pure white background
• Utilize shallow depth of field to draw viewer's attention to one object more than any other

You'll see why these objects are a bit in conflict in the longer description that follows.

Here's a diagram of the setup (where the person is depicted, assume a group of 3 medicine bottles).

Actually, I ran out of creativity on the diagram. Under the object is a white gatorfoam board and placed diagonally facing the object is another to reflect light up reducing harsh shadows.

An important note: The studio space is constrained so I can't achieve deep separation between the backdrop and the object itself. 4-5' is the most I can get.

Now, one of the keys to this image (below) is the shallow depth of field.

As you can see, the background lights did a pretty nice job of getting a white background but without washing the bottles completely out, it was impossible to light the white gatorfoam any more than where you see it. And the shadows are pretty nice, anyhow.

So here's the question lurking in this whole thing: With white bottle tops that are softly focused and pretty easy to mess up with a mask, what's the best way to get rid of the line where the background and the flat foam join (visible on left) and to bring up the foreground white, which is the flat gatorfoam the bottles are standing on, while leaving the bottle-tops their exact same luminance?

For the sake of discussion, assume I really like this setup and want to shoot scads of images this way, is there some really cool workflow I'm just not aware of to achieve the results of a completely white background other than pushing light up from below (which, in my experience spills all over the subject)?

Thanks!

Answer 1

Assuming you don't want to preserve the shadows (or that the shadows can be raised without destroying the image), you can try a variation on the Freemask system (which, with some Hensel strobe equipment, is semi-automated).

Essentially, it involves taking two images. The first would be the "normal" image, as you have here. The second image is taken with the subject still in place and all camera settings (focus and aperture in particular) the same, but with only the background lit. As long as your subject isn't almost perfectly transparent, that second image can be manipulated (using levels/curves and a bit of painting to fill in the holes) to form a good silhouette of the subject, but with increasing gradation along softer edges. You can use that silhouette image as a mask on an adjustment layer, allowing you to raise the background without touching the subject, or you can invert the image and use it as a mask on the subject layer to knock out the background.

It's a few extra minutes at shooting time, but it saves a lot of time in post - particularly if you have a subject that doesn't have sharp, easily-masked edges. And if you have a lot of spare cash floating around, you can automate it (as noted previously) with Hensel flashes and wireless controllers that toggle channels between exposures. (If you have even more money laying about doing nothing, there's even a two-camera rig with a beam splitter and a delay box that will let you do it with live-action subjects. It looks like a real pain to set up initially and doesn't even pretend to be cheap, but if you're doing production catalogue work for good bucks...)

Answer 2

Use plexiglass for the underground/background. It formes nicely with a simple wooden frame. Place a flashlight along with a softener (softbox etc.) from behind.

See http://fc-foto.com/27389031 The mirror effect comes from the glossy surfiace. Use a coarse one for your purpose. http://fc-foto.com/27389485

A minor change to the angle of the light from behind would provide you with some continous bright white and reduce the mirror. I was up to a small gradient which enables this mirror.

With this background light your transparent objects may even look more transparent - a bit like if they were glowing. I would like that effect but you may not want it at all.

As you can see, it is some rather compact set. That was in the eating corner of a friend's living room.