A Basic Understanding of your Histogram

I use my histogram all the time... I am a very much a chimper, "chimping" is a term used for a person that is always checking out the histogram and pictures on the lcd after a photo is taken.

The goal is to have the histogram stretch from the left to the right, without spiking upwards or outwards off the histogram. I would like to write something better about this but always seem to be lacking the time to put it together... trouble is it’s a technical tool and I am not a real technical person, I am very much a right brain type of person. Anyway here is my attempt... 

A histogram is a visual representation of the light in an image displayed in a chart like manner. The far left are the shadows and the far right are the highlights, the sections in between represent the varying degrees of dark and light in the mid-tones read from left (darker) to right (lighter). The spikes in the histogram represent pixels from bottom (fewer pixels) to top (more pixels).

The histogram is actually a very valuable and easy tool to use and understand once you know what it means and how to manipulate the exposure with your camera settings. The darker or more underexposed your image is the more you will see the histogram represent light on the left side of the chart. A normal exposure will show the light spreading across the histogram fairly evenly. An overexposed image will show the light pushed to the right of the histogram.

Here are some images with the corresponding histogram to help illustrate:

Granted these may not be the best examples but they do help to show how the light is represented using the histogram, the colors are also not accurate due to the process used to make the graphic.

Note the normal exposure and how the light is represented across the entire histogram, with some clipping (loss of data) of the shadows showing with peaks spiking upward and flowing off the far left and right of the chart. There is further clipping shown on the under exposed imaged with even more light falling off the left end but the colors in the sky (the mid tones) are nice and rich. The over exposed image shows lots of detail in the mid tones with some clipping (loss of data) shown by the light falling off the chart on the far right. Extremely over or under exposed images tend to be useless due to the loss of data, moderate clipping is OK and most often can be corrected depending on the format the image was shot in (jpeg vs raw) and the extent of the clipping.

A histogram does not necessarily need to be in the middle all the time, it just depends on what your scene may be. A winter scene for example may be pushed to the right of the histogram vs. a scene placed against a black or dark background which may show on your histogram pushed to the left. The challenge in extreme scenes with lots of contrast is to control the clipping that may be present, a histogram is a great tool that will allow you to make changes on the fly to your exposure, which is just one of the great things about digital photography!

These three images were actually taken this way on purpose for an HDR (high Dynamic Range) image that I created with them. The three images were combined and edited using software to create one image that would take advantage of the broad range or high dynamic range of light... but this topic is a WHOLE different post.

:-) 

Quick Tips

Sometimes it only takes a few easy steps to help create better pictures, here are a few to get you started.

• Eye level is where you want to be! Hold your camera at your subjects eye level, that may mean for kids and pets you have to kneel down to make the connection with your subject. Taking the picture at eye level creates a more personal and inviting picture.

• Place Your Subject Off Center and add some life and a new level of interestingness (fun word) to your images. By placing (composing) your picture in a way that moves your subject away from the middle of your camera's view finder you add some visual tension to the image which some say adds more interest, energy and appeal to images. Since most cameras focus on whatever is in the middle, you will have to remember to focus on your subject and then recompose or re-frame your image and take the picture.

• Read Your Manual! Yup, you bought that fancy digital camera and boy it sure is suppose to take great pictures, but how do I work it? Well... read your owner's manual silly! I am sure some underpaid and overworked nerd was tasked with putting together some of the most boring material you might ever put in your hands but HEY! If reading it keeps you from having to show up at a function and sit and play with your camera's menu system and buttons for 10 minutes, while you try to figure out how to change things and shots are passing you by like cars on the freeway... trust me, you WILL be better off and more confident about your picture making abilities. Your manual is your friend, keep it in your head or your bag!

• Move in close. Create picture with more visual impact by filling the frame of your view finder with your subject. As a rule of thumb when composing your image, you could move a a few steps closer or use the zoom to fill your viewfinder with your subject. Doing so puts the focus where you want it, highlights details that many not be visible from a distance and removes any unwanted elements that do not add to the picture. If your subject is small try using the macro/close-up mode (flower icon)  on your camera. This will maximize your cameras settings when using your lenses minimum focusing distances.

• Use Your Flash Outdoors. Pretty much every camera has one and they often get used with indoor photography and over looked when outdoors, but they can add a new dimension to your images when used outdoors and give your photos some pop! Use you pop-up flash to fill in the shadows with light when you have a strongly backlit subject like a portrait at sunrise or sunset. ON cloudy days you can use your flash to brighten up your subject and make them stand out from the background. Also consider when using your on camera flash outdoors using your flash EV compensation to set the flash one stop lower then your exposure to create a more nature feeling image.

• Shoot Vertically. Often we get comfortable taking pictures one way, holding and seeing images through the view finder the way our cameras were designed in landscape mode. Shake things up a bit and rotate your camera sideways and take some pictures vertically, doing so change the composition and give new life to a particular scene. Shoot vertical things vertical like people or tall buildings or landmarks.

• Adjust your ISO. One of the great things the digital age of photography has given us is the flexibility to adjust our ISO setting on the fly. ISO stands for International Standards Organization which has defined a set of standards for sensitivity of today's digital sensors. A typical range for ISO settings would be from 50-3200. These settings can be adjusted for use in different lighting conditions such as direct sunlight vs cloudy or indoors vs outdoors. As a rule of thumb you want to use the lowest possible setting for the situation to have the best file quality possible. Outdoors in bright light you can use 100 as you move towards lower light scenarios like shade or dusk you might wish to try 400-800, as you move indoors taking pictures with out the use of a flash may require settings of 1000-3200 depending on the camera. The trade off of using high ISO settings is the image tends to become more grainy (digital noise) with each incremental setting moving upwards from 100 reducing image quality, this can be corrected most of the time with the use of post processing editing software.

• Make Mistakes! Don't be afraid to make mistakes, some of our best photos will come from those "Oops!" moments where we did something that was outside traditional thinking or did not follow the rules. Photography has many rules to help us understand the concepts and techniques for capturing nice technically correct images... but what happens when we experiment? We tend to make mistakes and those can lead to some very creative and beautiful images, which end up being favorites. So don't be afraid to make mistakes... you never know what you will come up with until you try.

• Shoot outside your comfort zone! Often we find ourselves taking shots of the same type of subjects over and over again. Shooting with in our comfort zone is fine but can do little for the over all growth of a photographer. We settle into routine and comfort knowing the subject, scene, light and potential results. Challenge yourself and step outside your comfort zone to shoot new subjects, scenes and lighting conditions. Try a new mode on your camera and work with that or take only pictures with your flash for a week. If you shoot mostly inside go outside and visa versa. The goal is put yourself in new situations that will give you a chance to learn new things and increase your skills taking pictures.