I’ve seen lots of talk about histograms in the blogosphere lately. I’ve been meaning to post some quick tips about using the histogram for quite awhile (because I get asked about it all the time), so seeing these other posts has prompted me to finally do so.

But wait, there’s more! I’ve actually taken this as an opportunity to to kick off a series of Quick Tip posts about photography that I will gradually release over the coming weeks. These are all based on a bunch of reminder notes that I’ve saved over the years that helped me remember some of the finicky little details about photography. These things aren’t always obvious to new users, and they really helped me out as I learned the craft. Fortunately they are also really easy things to share!

So here’s the first one…

Using a Histogram

NOTE – If you don’t know what an image histogram is, go to Wikipedia’s Histogram article first. In short, a histogram is simply a relative indicator of how much of your image is dark, or light, or somewhere in between.

• Right Side – Indicates the brightest parts of the image. If the curve touches the right side of the chart window then parts of the image may be pure white or overexposed.
• Left Side – Indicates the darkest parts of the image. If the curve touches the left side of the chart window then parts of the image may be pure black or underexposed.
• If the chart touches both sides of the chart window at the same time then the scene is very contrasty. You will have to choose to expose correctly for the dark parts of the image, the light parts of the image, or somewhere in between. But you can’t possible expose for everything at the same time. You could also consider shooting a bracket and blending the exposures in post (eg. shoot for HDR).
• If you want to “Move to the Left” (or make the image darker) then increase the shutter speed, increase the F-stop (which actually means to use a smaller aperture), or use a lower ISO setting.
• If you want to “Move to the Right” (or make the image brighter) then decrease the shutter speed, or decrease the F-stop (which actually means to use a larger aperture), or use a higher ISO setting.

Almost every new SLR camera shipped in the last few years has included a feature known as “Live View”. For Point and Shooters it has been a given that you would be able to see a live image of your intended subject before you squeeze the shutter, but for digital SLR’s it has always been a little bit more complicated.

The thing is, there’s a darn mirror inside the camera that gets in the way, and it has to be moved before the camera sensor can see the same scene that the lens sees. It took the manufacturers a few years to figure out how to make it all work elegantly (in fact it’s still not perfect because autofocus performance takes a big hit in live view mode, but that’s a subject for another article). In the mean time SLR shooters never got used to having live view on the back of their cameras, and it’s one of those features that gets used very rarely (almost never) by most serious photographers.

Here are 5 reasons why you should use Live View for landscape photography:

1. Bigger Viewfinder: Let’s face it, the viewfinder in your SLR is small. Even if you’ve got one of those fancy-pants professional cameras that shows 100% of the image that the sensor sees (most non-pro SLR’s only show 90-95% of the scene), it’s still very small. With a bigger view you can get better compositions and more easily see the distractions and annoying backgrounds that you might not notice otherwise. Simply put, bigger is better baby!
2. Testing Critical Focus: While in live view mode you can zoom the image on the LCD (typically 5x or 10x) to get a much better idea of what you are actually focusing on. This is particularly helpful for macro photography, but it’s also great for landscapes.
3. Stronger Compositions: The image displayed on the LCD during Live View typically includes grid lines to help you compose your image. These lines can help you check that your horizons are straight and level and that your trees and buildings are vertical. They can even help you improve your composition by clearly showing guidelines for compositional rules of thumb such as the “Rule of Thirds.”
4. White Balance Preview: When you change the white balance setting in your camera, the image in your viewfinder doesn’t change, so you really can’t be sure how it’s going to look. Fortunately the image on the LCD changes instantly to show how your white balance affects the image. Sure, you can change the white balance in software (such as Adobe Lightroom) later (if you shoot RAW), but why not get it right in the camera instead? I find this feature to be invaluable when I’m trying to decide if I really have a good image in front of me…
5. Exposure Simulation and/or Live Histogram: For some users the single biggest reason to use Live View is for the exposure simulation (the live preview image in the LCD will automatically adjust based on the exposure settings to display the brightness of the final image). Alternatively you could simply choose to show a live histogram (which would also represent the final image rather than what you’re seeing on the screen) overlaid on the live image. Both of these features are very useful for preventing blown highlights or underexposed images. You can even use both at the same time.

There are many other great reasons to use live view for all types of photography. These are just a few of the best reasons that are most applicable to landscape shooters. Do you use live view? Please leave a comment telling me about your experiences with it… If you haven’t used it before then you should definitely give it a try on your next shoot!