Some of the most challenging intra-oral photos to master are the mirror shots. The placement of the retractors and the mirror, controlling fog and then aiming and focusing are all part of what makes these photos my favorite to take. In some ways it feels like I am playing the game twister by the time I am ready to press the button and take the photo. With all of this when I then look at the photo and the exposure or color aren’t right I’m frustrated! One of the biggest problems that I have with my mirror shots, especially the occlusal, is that they come out with a bluish tint to them.
This is not a new issue for me, and I finally understand why, and what I can do about it. In the past I have tried to adjust the F-Stop, it helps, but then I also alter the exposure and the depth of field. At the root of the blue or red color in a photo is the light intensity ( flash), when the flash is too intense the photo takes on a bluish cast, and when the flash is less intense the photo will appear reddish. With this knowledge in hand I now have two ways to adjust so my mirror shots are taken at the right exposure, depth of field and have the correct color balance.
Since I shoot with my flash on manual, one way to correct for this is to simply reduce the power of the flash for my mirror shots only. This will also require adjusting the f-stop to keep the exposure correct. I verify exposure by setting my camera to display the histogram with every photo. An additional way to correct this is to adjust white balance, which I have on a custom setting of 5500K, for my mirror shots. If the color temp of the camera (WB) is set lower than the actual photo, it takes on a bluish cast. Therefore by increasing the white balance to a higher kelvin temperature it will correct this. If the color temp of the camera is set higher than in the image it takes on a reddish cast, so simply dial down your WB to a lower kelvin temp.