Proper exposure and an extremely sharp display play an important role in product photography. It always becomes problematic with shiny and reflective surfaces. For this reason, I use a so-called polarizing filter on my camera. These are relatively inexpensive as an attachment lens for almost every camera lens. With a polarizing filter, possible reflections on the subject can be reduced if set correctly.
What is a polarizing filter, and what is it used for?
Polarizing filters consist of a firmly screwed thread and a rotatable glass. They are screwed directly onto the lens with their internal thread. Under certain circumstances, it is advantageous if the polarizing filter also has an external thread to place another filter on it. Among the best-known manufacturers are Walimex, Hama, Hoya, and B+W. I have had good experiences with the cheap Hama models. Polarizing filters can still be used even with the lens hood attached. Their main task is that dull colors and weak contrasts can be compensated for by turning the glass pane. For example, if you want to photograph a real blue sky, a polarizing filter is the best way to do so.
The application of a polarizing filter
In product photography, a polarizing filter can improve colors and contrasts. For this purpose, I put the camera on a tripod and took product photos with a differently adjusted polarizing filter. After evaluating these photos, the difference is quickly noticeable. Thus, the colors appear stronger, but the details of the drawings become clearer. Reflections on smooth surfaces, which are caused, for example, by a laterally installed spotlight, can be attenuated or disappear completely depending on the direction of rotation of the filter. I achieved the best results by photographing the lens at an angle of 30 to 50 degrees. By the way, motifs behind glass panes can also be photographed with a polarizing filter so that the reflective glass pane in the foreground becomes almost invisible. It is important to know that at least 1 to 2 f-stops are lost by using a polarizing filter. For this reason alone, I think using a tripod for product shots makes sense.
The differences between circular and linear filters
In today’s world, circular polarizing filters have prevailed. In contrast to the older linear filters, this does not affect the measurement technology of the camera. Structurally, however, circular polarizing filters on one side also consist of a linear filter and a rotatable delay layer. Nevertheless, this is referred to as a “circular polarizing filter.” In the first step, unpolarized light passes through the linear polarizing filter element, allowing a certain polarization to pass through depending on the rotation angle. The second component is reflected. The linearly polarized light then falls on a delay layer, with its optical axis rotated by 45 degrees. This rotation causes a delicate superposition of two linearly polarized light rays perpendicular. As a result, a circularly polarized light flow is achieved.
My conclusion
To improve colors and contrasts or reduce reflections, hardly any photographer can avoid using a polarizing filter. Even taking into account the low light loss, I think the use of polarizing filters makes sense. Impressive shots can be taken with a little skill in the shooting setting.
