Have you ever tried to make a translucent object stand out against a white background? It’s darn challenging until you have the right technique. And if you are shooting product or food photography you will need to know how to do this.
Whether you are shooting against glass or even plexiglass you must avoid illuminating your subject from the front. If you do it will create a white surface reflection.
And that means you won’t capture the translucent subject in a flattering way.
The way to tackle this lighting problem is to subtract lighting. This simply means adding black cards, sometimes called flags or gobos, which will create dark reflections that will define the edges of your translucent subject.
You will also need to create the right halo for your particular subject. I often attempt to achieve a gradual fall off from light to dark. You will have to play around with your reflectors to find the right size for your particular subject. Test your reflectors against the background light and your background.
If you get your reflectors too close it will create a hard edged circle instead of a pleasing halo. But when you get too far away from your sweep your bright white central highlight will be dimmed to an unflattering shade of gray.
Some of the gear I use to achieve this effect is a pulse strobe head and power pack with power duration of 1/8000 sec. I also cover my reflector with full blue color conversion gel.
This technique is essential for product and food photographers. Capturing images of a glass with ice or liquid in it can be incredibly challenging. I spent a number of years dialing in a way to consistently get these translucent subject shots right but once you get the hang of it you will be able to handle this situation with relative ease.