Earlier this week a photographer that I have been training had her very first client shoot. Teary eyed I offered to come along for moral support and to watch my little birdie take her first step from the nest. She did great! Though she ran into a single very specific problem.
All the images on the back of her LCD looked washed out. She was having problems with the high key backdrop causing flare in her lens. I offered few quiet pieces of advice and she was able to solve the problem but the situation had me thinking that this may be a challenge that many photographers face.
So I spent a few hours in my studio recreating the problem exactly as she faced it so that I could show you how to solve it. Every example image in this tutorial was shot at F5.6 and are un-edited in Photoshop. I opted to shoot a still object for the ease of instruction, however, this problem is something any photographer can run into when making any high key image.
The light setup is pretty simple; two background lights on either side of the seamless at about camera level pointing towards the center of the background. I also included another strip bank to camera right to light the front of the bottle and create a highlight.
As you can see, even though the bottle is fairly well exposed having no blown out highlights or shadows the contrast is extremely poor do to flaring that is caused by light bouncing off the backdrop.
Step 1: Minimize Background Exposure By Lowering Light Power
The first step to solving this problem is likely also the most obvious. The background lights are simply too bright. You don’t need to blast enough power at the backdrop to put a spotlight on the moon. By simply scaling back the background strobes by a couple stops you can see that the flare noticeably diminishes.
You also might notice that the background is no longer fully white as there is now a subtle gradient. The lights are merely not bright enough to evenly expose the backdrop to create the high key effect. Furthermore, there is still an annoying amount of flare.
Lens flare is caused by light bouncing into your lens and scattering at unwanted angles. In the case of this image the flare is being caused by light bouncing off the white backdrop and directly back at the camera.
By lowering the background lights from being at camera level to being on the floor we are able to angle them up so that the majority of the light skims across the seamless and bounces into the ceiling. Not only does this help reduce the flare even further but it also leads to more even distribution of light throughout the seamless eliminating the gradient problem from the previous image.
For the most part we now have the background problem nicely handled, however, the image still has a small hint of flare. This remaining flare is actually caused by direct line of sight to the strobes. Even though reflectors are being used to direct light away from camera there is still noticeable spillage.
In order to solve this problem we can set up a pair of flags to block direct line of site from camera to the background lights. In the case of this example image I put up two large 8’x4′ v-flats to ensure that even any oddly bouncing light would be prevented from finding its way into the barrel of my lens.
We are rewarded with a nice, rich, flare free, image.
Flaring manifests as poor contrast. Lightroom has a nifty contrast slider. It may seem too obvious to simply not worry about flaring in camera and to let the computer solve those annoying flare problems.
This is, however, not good. As you can see in the example image that by cranking up the contrast post exposure we are able to eliminate the flare at a cost. Not only is there a loss of detail due to shadows being blown out but also a blue tint is introduced which ultimately will lead to color problems with the rest of the image if we were to use selective color to attempt a fix.
Hover over the image to see before.
Normally, we use lens hoods to control flaring. A lens hood is designed to block directional light that is finding it’s way into the lens from outside of frame. However, in the case of high key flare the haze is being created by a light source that is in your frame and thus you cannot depend on a hood to block the errant light.
Its no secret that while even though we photographers tend to love our gear we also love to remind ourselves that great photography is about the photographer and not the gear. Which for the most part is true but at the same time gear can also often help you deliver higher quality images and allow for more radical situations that would have been otherwise very difficult.
To create the following photo I reset the lighting back to the original set up with the strobes fairly bright at camera level. The scenario that was causing a ton of flare.
I then switched away from the cheaper, entry level, 50mm prime that my student had been using and instead popped a much more expensive 100mm macro lens onto my camera that features fancy coatings while also enjoying higher quality glass.
As you can no doubt see, even with the lights turned up so high that they were causing unusable flare on the previous lens the better quality lens is able to cut through the flare without a problem and is actually creating a higher contrast image than even the best version taken with the cheap fifty.
Creative problem solving is definitely handy when dealing with flare. Even with the cheapest of entry level lenses solid technique can eliminate that flare and allow you to create great images. However, having to constantly tinker with flags and light angles to protect against background bounce quickly becomes tedious, especially when working with a tight timeline and thus it may eventually be worthwhile to explore upgrading to a better lens which can handle background flare much more effectively.