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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.
Accurate Color Temp
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.
Reddish Occlusal Photo
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.
Hi Lee Ann,
Great blogs!
I was curious as to what camera setup are you using; make/model, lens, and flash system?
Thanks!
I have two set-ups in my office. My primary camera these days is a Nikon D90 camera, with a Nikon 85mm lens and a Metz Flash (http://www.photomed.net/d90.htm). I have been using it for about four months now and love it. I also have a canon 5D with a Canon 100mm lens and the Canon MR14-EX ring flash. They are both great cameras. I purchased my Nikon for a few upgrades, live view, limited HD video and the decreased weight with the Metz flash.
So are you keeping the white balance at 5500k for All photos? or do you go in and change for just the mirror shots? Do you happen to know how to set the view finder to have your histogram show?I have a canon 10D. Thanks
Hi Ann,
I shoot with my white balance set at 5600K ( custom setting) for my close ups and then increase the white balance setting to 6200K for the occlusal mirror shots, often I have to use a middle setting like 5800 K for the buccal retracted shots. On my Nikon I have a WB button on the back I can simply press and then turn the front dial to change the kelvin setting up and down. As for the Canon histogram, you have a button on the back that displays the image, simply press it again once the image is up and it will display the histogram. There are several display options, so you may have to press the display button a few times to get the one you want which is exposure histogram not the RGB display.
Hi Lee Ann,
I have some ideas why your colors are shifting, but I need to know about some additional camera settings. Too much to write now, however,
I’d love to talk to you about this topic. If you get time please call me at 480-614-1597.
Thanks!
Steven.