Welcome to TIPsy Tuesday, my weekly posts of Tips to get better shots. Every Tuesday I will post a Tip on topics such as: camera functions, composition, coordinating, post processing and many many more. So if you haven’t as of yet, be sure to subscribe to the RSS feed. You don’t want to miss out on this great new series. And if you have ANY questions or suggestions please comment below. I promise I will get back to you, because this series is all about sharing and interaction.
Today’s Tip: Understanding Histograms
Possibly the most useful yet least understood tool available in digital photography is the histogram. In today’s TIPsy Tuesday’s tip we will look at what a camera histogram tells you and how best to utilize that information.
Most digital cameras of today, from the point-and-shoot to a digital SLR has the ability to display a histogram for an image just taken. This will depend on your individual camera and is where I have to mumble the dreaded words: get your manual out. I know, I know, EVIL.
I want you to think left and right AND up and down. The histogram gives you a lot of info but it is how you read that information that makes it useful and is what we will be discussing today. When thinking about histograms think TONES. Dynamic tones: from deep shadows on the left to bright highlights on the right. See: left and right. What about up and down? This gets into the peaks on the histogram. Think mountain ranges. When you have a peak it is stating that you have more pixels in that Tonal range. IE. on the histogram shown below: The medium tonal range is the major peak.
HUGE TIP: Just making sure you are paying attention: Set your lcd on the back of your camera to include a histogram. Trust me on this, because sometimes the lighting is so bright you just can’t make out the image on the back of the lcd but having the histogram to review you will be able to see if you are clipping on the left or right side: AKA: clipping black and/or white. Clipping? Yes and we will get into this shortly, but clipping is when you have blown out blacks or whites in your image: Lost details. For most situations, you want to avoid this.
Understanding a histogram is about studying many of them. You want to get to a place that you can look at a simple histogram and visually know that that image is going to be a nice tonal range of all areas or very light or even very dark. The histogram holds that information, it is just up to us to get familiar with it.
Take the example above: Is it a light image, full of sunshine and light? Since I see no peaks on the right side … heck there really isn’t any recorded info in the white zone … so definitely not in the bright range. The biggest peak is the medium OR middle tonal range. This tells me that the image is mainly in that mid gray range in tones. There is also a lot of pixels in the black range pushing up to the clipping line. So possible clipping in black. Is this a bad photo? Many people see histograms and think a good photo has to be evenly spread across the 5 regions … this is a necessity for ensuring you have a good shot, no?
NO. It really depends on the lighting situation you are shooting in. Remember the post about knowing light? If you haven’t read it I suggest you hop on over and take a look. It is very important to understand the situation that you find yourself in when it comes to the light. Photography is all about light. And the histogram is a graphical representation of that particular situation.
Going back to the example above. We can visually tell that thanks to that histogram the image will not be giving full tonal range but we also know that we are not shooting in a situation where it warrants that. The histogram is from the photo below:
As a painter I was taught to squint my eyes to visually see tonal ranges. I still do this with my photography. When squinting I can see that most of this image is in the medium range and the background is the bulk of the Black peak. And as for the lack of white: yes the cat has some white and light areas on him but if I wanted to make that the focus I would have overexposed a stop to lighten the cat but would have risked bringing in more detail in the background and I was looking to focus the attention on his face. So for this situation IN this light, this was the perfect exposure.
Wait, did I mention exposure? Yep, sure did. Don’t you love when I sneak in another component. Histograms are useful for exposure and white balance. Darn it Deborah! Two other terms. But I’m not going to get into all of it since this post is already long! What I will say is there are some additional tools you can purchase that are used with the histogram to help set white balance and exposure. IF you want to rely on the histogram to check exposure I suggest focusing on the extreme right and left and make sure you are not clipping. If you are then you have lost data and need to readjust your exposure.
Now some examples of different histograms and their partnering image:
Wide range of tones but weighted more in the left side (dark tones).
Squinting eyes, should be able to see the darker to midtones are more apparent in the above image.
Another wide range of tones but still with a high pixel deposit in the black range.
Looking at the image, the reason for the high pixel deposit is the blue curtain behind them.
I could put a ton of images up here with their histogram but that is a lot of work and besides I want you to go through your images, looking at the histogram and seeing if you can visually understand the peaks.
But one more before I end this. I mentioned exposure and watch your left and right side for clipping. There are exceptions to that rule. Sometimes you want to clip or come as close to possible to that line without crossing it.
This one is clipping on the left side so I’m losing details in the black. Seeing this I could reshoot it, bumping up the exposure a 1/3 stop and saving the black, but I’m in control, not my camera! I visually knew what I was going for and went for it.
As you can see: blacks were not important to me in this shot. It was a background that I wanted to go away … I’m happy with it in the tonal range it is in. There is enough pop in the background that it isn’t flat but not so over the top in details that it overpowers the point of this image: the subject.
Basically, learn your histogram; learn the importance of light; and understand what your final product you are trying to achieve should be. Use the histogram to help get you there put don’t be afraid to throw some of the rules out the window when it inhibits you from reaching your goal.
And since histogram is a major component in photography: Think white balance, exposure, post-processing, etc. … I will be doing additional posts on the topic. How many? Depends on how in depth I take this, but stay tuned! And if you are looking for some specific answers to your questions in reference to histogram, do comment below and I will try to get them answered within the series.
Until next week, CHEERS!
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Deborah Chetwood is an award winning, published photographer in Austin, TX who specializes in stylized children's, senior's and glamour photography. To find out more about the artist click HERE.
Please visit our other website for information on the Texas Vogue: Contemporary Glamour.
by Deborah Chetwood
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