HOW TO READ A HISTOGRAM
by
Heather Shimmin
Click the Image for Info
Before you can read a histogram, you first need to understand what one is. A histogram is an exposure graph. It has nothing to do with white balance, focus, composition, or image quality. The pixels from the image are looked at individually and mapped out on a graph according to their density (the amount of information recorded) from darkest to lightest. This instantly tells you if your image is correctly exposed, and nothing more.
This may cause you to ask yourself why that expensive SLR can't get the exposure right and why can't you just look at the LCD display to see if the image is properly exposed? Unfortunately, the answer to your both your questions is no. Neither are reliable ways to determine exposure. That's why using a histogram is such a useful tool.
AUTO EXPOSURE
When you put your camera on automatic mode, you give up all control to the camera. As smart and high tech as your camera may be, it's not perfect. When you camera meters the subject, it sees it as 18% grey, be it a white unicorn or a black stallion. Grey. Your camera adjusts its exposure accordingly to compensate, and you end up with an over- or underexposed image.
THE LCD SCREEN
The biggest problem with solely relying on your LCD to determine exposure is the screen's size – it's just too small. Since you can't really see the image in a large enough scale, you won't be able to tell if it's exposed correctly.
Click the Image for more Info
Another problem is the brightness setting of the LCD screen. You may have it set higher in order for you to read the menus better which will make your images look washed out. Your images will appear overexposed when in fact they are not. The only way to be 100% certain that your images are exposed correctly is by looking at the histogram.
WHAT THE HISTOGRAM IS TELLING YOU
A histogram is similar to a bell curve, in that you will have a wide range of points, but most of them will fall in the middle. In this example, the bell curve is charting height. Some people are very tall or very short, but most fall somewhere in between.
In charting pixels on the histogram, you will have a range of dark pixels and light pixels, but most of them will be in the middle, or mid-tone range. If your histogram does not resemble the traditional bell curve shape exactly, that's okay. This just gives you a basic foundation of what you are looking at.
The left histogram shows that the majority of the pixels are on the left, meaning that they are too dark. When pixels touch the sides of the histogram, in this case the left side, it indicates that the image is underexposed and too dark.
The histogram on the right shows the pixels congregating on the highlights side, or far right side. They are also touching the right side indicating that the image is overexposed or too bright.
The middle histogram displays most of the pixels in the middle, neither too dark nor too light, hence, a correct exposure. Few pixels touch the sides so you won't see too many dark or hot spots in the image.
If your histogram looks something like a reversed bell curve with most of the pixels on the right and left sides, then you are shooting something with extreme shadows and highlights. This is the case with the image of the tree below. The bright, noonday sun contrasts with the dark, backlit tree. There is no way to have it both ways – a correctly exposed sky and a detailed tree – so you have to decide which is more important. In this case, I exposed for the sky and let the tree go dark, and altered the histogram to the correct bell shape.
FREE REPORT
Reveals Insider Professional
Tips And Tricks For Taking
Awesome Photos With Your
Digital Camera (Even If You're
A Complete Newbie)...
CONCLUSION
A histogram is an important tool in determining exposure. It is the only reliable tool to alert if you if your image is over- or underexposed. It will not tell you if your WB setting is correct, if the image is in focus, or if you have a National Geographic quality image. Learning how to read a histogram and understanding how to use it will help you dial in that correct exposure instead of guessing what it should be.
Please be sure to check out the site, and get in on the ground floor of this huge opportunity! All you have to do is visit www.kachoozie.com and sign up !
Other blog articles you might want to read:
Digital Photography Secrets
How to Sell your Photos
Travel Photo Tips
Working with Nudes
Tips on Portrait Photography
Shooting Still Lifes
Studio Lighting Techniques
igtial Camera Tips Part 1">Digital Camera Tips Part 1
igtial Camera Tips Part 2">Digital Camera Tips Part 2
igital Camera Tips Part 3">Digital Camera Tips Part 3
Working with a Flash
Filters
Fun Photo Techniques
Low Light Photography
Backing up your files
Exposure
File Types
Naming Files
Tripods
Model Releases
Working for Free?
The Sound of Color
Post Processing
Cheap Memory Cards
Earn 200.00 a day
Aperture vs Lightroom
Scanning Services
How to Photograph Fireworks
How to Read a Histogram
How to Set White Balance
Black and White Photography
Fashion Photography
Great Website Portfolios
Please visit our other sites:
Kachoozie.Com
Kachoozie.Net
Prophotosales.Com