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Common Questions ~ Custom White Balance & Exposure
|Often I get questions about how I set my exposure and white balance, and I wish I could respond to each person's inquiry, but every once in a while I'll try and tackle a few birds with one stone by posting what I do here on the blog. Please note, this is what I do, and it works for me, but it's not the only way to do these things. By the same token, if you've got a way that works for you that you think is better, I'd love to hear how you do it if it will make my photographic life easier. Also, I know a lot of people have the philosophy that if they shoot RAW they don't need to worry about setting their WB. It's true that you can easily change this in post work, but for me I don't always shoot RAW and even when I do, it's one more step I have to do in post processing that takes a little more time. By just taking a few extra seconds before I start photographing, I save myself time on the back end. Again, just the way I do it.
Also, I should note that I don't do this for every session because, well, trying to use the method below while quickly moving around in different lighting environments (i.e. chasing quickly moving kids around during a session where they're in shade then bright sun, etc...). I do a modified version of the approach below for those types of sessions. The approach I'm going to explain works great when the subjects you're shooting have a longer attention span and you've got a little more time to set up the shot. For me, that's engagement, bridal, senior, and some family sessions in addition to any commercial/headshot work. So, on with the explanation.
I use a PhotoVision Digital Calibration Target to set my exposure and custom white balance for my images. I have my client or - in the case of the image below - my lovely assistant hold the calibration target with the white stripe closest to the light source. The reason you need to have the white strip closest to the light source is because in some situations you'll have rapid light fall-off (if your light source is close to the subject) and you want to make sure you don't blow out your highlights. If you had a noticeable change in the lighting as it goes across the target while the white strip was in the darkest lighting, you're more likely to end up with blown out highlights in your image which I'll talk about more below.
In the image below, there was big open sky to Kylie's left with the house blocking light on her right which is why I had her hold the calibration target with the white strip on her left.
|I get close enough or zoom in to take a quick image of just the calibration target making sure to include at least a little bit of all three sections to make sure I'm setting my exposure for shadows, mid-tones, and highlights. I shoot in manual mode and I start with my first exposure by setting my aperture and shutter speed and spot meter on the gray mid-tone strip. If my in-camera meter tells me I'm a little overexposed (again, when spot metering the gray section only), I adjust my shutter speed until it tells me I (in theory) have a perfect exposure. Then I fire one off and look at the histogram and see if any highlights or shadows are blown out. In the histogram, you'll see 3 distinct spikes (one for each section of the calibration target). Remember, you're spot metering the gray section only but your framing of the image needs to include a little of all three sections.
Generally, I like my images to have a little more contrast, so I like to see my histogram with the right side spike (representing the highlights) as close to the edge as I can get it without touching the edge. For me and my particular Nikon D3 camera, that usually means I have to over expose a third of a stop or two from what my camera's spot meter is telling me when I meter the gray mid-tone section.
The image below represents my final adjusted exposure test image of the calibration target and the inset shows the display on the back of my D3. Notice the histogram with my exposure adjusted slightly to overexpose from what the camera was telling me but still without any blown out highlights. Also, at this point, my white balance is still set on "auto".
|Next, I want to quickly set a custom white balance. I shoot with Nikon, and so the process may be a little different for Canon and other shooters and even some Nikon users with different models.
I simply zoom in to fill the frame with the calibration target, set my white balance to take a custom reading (in my case I set the WB to "pre" for preset and then hold the WB button on the camera for a couple seconds until the "pre" symbol starts flashing on my camera's LCD. Then I quickly take a shot of the calibration target (you don't need to be focused on anything for Nikon users to take a custom white balance image).
The image below represents the adjusted custom WB setting. Note: I think I took a couple test shots of Kylie and and felt like I had gone a little too far in my exposure compensation as you'll notice the shutter speed was 1/2500 in the above image and is 1/3200 in the image below. This is also why the 3 spikes in my histogram have shifted slightly back to the left.
|Once I have my exposure and white balance set, if I'm shooting in manual mode I can now just fire away without having to mess with any settings, and I'll get consistent exposures as long as the lighting doesn't change.
Below is a comparison of 3 different WB settings of the same exposure - auto, shade, and custom. While auto's not bad, it looks a little cool to me. Cloudy actually looks pretty good which isn't surprising since Kylie was standing in shade from the house even though it was bright and sunny out when we took these test images today. Finally I like the warmth of the custom WB image. For me personally, I like my clients to look warm and lively in my images. Just a personal preference, though. In the images below, you can also see the brick in the house behind Kylie warming up in each image as well which is also not surprising since it's close to a skin tone color.
|I know in reading this it can sound complicated and like it takes too much time, but after you do it once, it becomes 2nd nature and literally only takes about 15 seconds to do the whole thing... and you'll save yourself some work on the back end.
Anyway, hope that helps a little. Happy shooting!