Taming IR Hotspots
I used to agonize about which lens to use when shooting infrared to avoid the dreaded hotspot. This is what I’ve learned about how to tame them.
Since moving to an all ACR/Lr workflow for processing my infrared images, I’ve learned that the radial filter tool can be immensely helpful in taming, if not removing entirely, hotspots which impact the color, saturation exposure or contrast of an image shot with a lens with less than ideal coatings and characteristics.
I start with a selection positioned at the dead center of the image, with a 50% feather. I then started out by using the Dehaze tool in combination with subtle white balance adjustments. It wasn’t long though before I discovered that the Dehaze tool was not the end-all, be-all solution. The white balance was almost always a necessity, but sometimes the luminosity issues needed the exposure, contrast shadow, and highlight tools. Sometimes Dehaze produced great results in conjunction with the Vibrance and Saturation sliders. Color and luminosity range masks also helped.
Sometimes the selection circle and it’s feathering needs to be adjusted. I try to avoid using two radial filters because of the complex variables it creates. But there have been times when it’s done the trick.
But through this all, it’s just reinforced my belief that with the right processing, any lens can be used successfully for infrared photography and finding the way is just a matter of time and perseverance. And this is good news for mirrorless shooters, whose lenses have been said to be poor performers for infrared photography.