When to Use a Polarizing Filter #102

When to Use a Polarizing Filter #102

In a recent photography Q&A, someone asked the pro-photographer if they thought it was useful to use a polarizing filter when shooting macro photography. In particular, they were asking about flowers. Although I did a podcast about polarizers way back in episode 19, where Dr. Rebecca Theilmann explained what polarization is and what causes it, I thought it was worth revisiting, as people still seemed to be a bit confused. To summarize: Polarization is when light reflects off certain objects and comes back at us wobbly. This is what causes glare. This is most obvious when you're photographing from a boat because you're surrounded by light which is being reflected off of the water, making it rather glary. Very often this glare will make your images seem less sharp because the light is, shall I say, smudgy? And don't forget, fundamentally everything we're capturing is light.

But what about other times? Surely there must be occasions where you would want to use a polarizer other than with water, right? Yes. The answer is yes. I think the best way to know when to use a polarizing filter is simple. Use a polarizing pair of glasses. If what you see is improved by the glasses, then you would want to use a polarizing filter. It's as simple as that. I had noted to Dr. Theilmann that very often my polarizing sunglasses seem to make things sharper. I have pretty good vision, but the sunglasses just seem to make my vision even better. This is because the sunglasses polarize the light, and in doing so, it made the wavelengths of light travel at a straighter line before it hit my eyes and therefore the scene is less smudgy. So if you find that the object you're shooting looks better with the glasses on than off, then use a polarizing filter. If not, then don't. It's that simple. So in the case of the flower, the answer is no. You would not use the polarizing filter in most instances. Why? Because most flowers have a matte surface, so you don't get a lot of glare bouncing off their surfaces. On the other hand, if you're shooting a flower like the Anthurium, I hope I pronounced that right. It's also known as the flamingo flower, which has a shiny, waxy finish. You would likely benefit from using a polarizer. Another thing, I was recently in New Zealand shooting landscapes, and in particular, I was shooting a river that was crazy clear. The water was so clear that you could see the rocks on the bottom of the river. Without the polarizer, the photo did not show how clear the river was due to the glare from the sun on the surface of the water. However, I also noticed that keeping some of the glare actually made the picture more interesting. So although most photographers would remove the glare as a matter of practice, I think you should also step back and ask yourself if it's nice to retain at least some of that glare. I wish there was more of a black and white answer, but at the end of the day, this is an art, and there's never just one answer. I hope that helps. Until next time, keep on shooting.