A Guide To HDR Photography - Capturing HDR Sequences :: Digital Photo Secrets

A Guide To HDR Photography - Capturing HDR Sequences

by David Peterson 17 comments

Do you want to make your pictures more vibrant? As photographers, we are always looking for colorful times of day, colorful subjects, and colorful lighting. This isn’t easy. It usually means spending hours and hours just walking around scouting out locations. It means taking the time to learn manual camera settings to get the exposure just right.


What if I told you there is a way to get the best and brightest colors from every photo you take? Yes, it involves more work, but just look at the picture below! Every picture you take could look like this if you learn a new technique called HDR photography.

What is HDR photography?

HDR means "High Dynamic Range". A HDR photo is a shot that shows both the brightest and darkest areas of your photo at the same time. Some great examples of HDR photography can be seen on Pete Carr's website.

I know what you're saying - 'doesn't my camera already do this'? Interestingly, no! Our digital cameras are nowhere near as good as our own eyes at perceiving large ranges of brightnesses. They can only measure a small range of all brightness levels possible at the one time. Cameras do a marvelous job at hiding this by giving you the ISO and Shutter Speed settings to fiddle with. But all they do is change where that range is located in the brightness spectrum - they don't make that range any larger. The below image might explain this concept in more detail.

The camera's brightness range (the yellow arrows) is only a small part of the total brightness that's possible (blue arrows) from ink-dark black to looking-at-the-sun bright. When you take a photo, your camera takes a reading of the light in the scene and in effect moves the arrows left or right on the scale by changing the Shutter Speed (and in some cases, the ISO).

Your camera's yellow arrows can only slide left or right on the scale. They can't grow larger. Anything darker than the left arrow will be shown in the photo as black (usually called under exposed). Anything brighter than the right arrow will only be shown as white (usually called over exposed).

A classic example that's common to us all is the image on the right. The camera sensed the light outside and set it's shutter speed so that the outside scene was correctly exposed. Unfortunately the singer, who we really wanted to see, was darker than the camera could register. In other words, the singer was outside the brightness range of the camera, so that's why he's all black.

Remember, because the camera can only take a limited range of brightnesses at the one time, telling the camera to use the singer for it's light measurements wouldn't have had the desired effect either. We would have been able to see the singer, but everything outside the window would have been bright white.

That’s just the way it is, right? Not if you try this out...

The Real Secret Of HDR Photography

HDR photographers can take photos with the whole range of brightnesses. They do this by taking multiple shots of the same scene, all at different exposures. They run those exposures through a computer program that stitches everything together to create a rich scene that takes advantage of every brightness available. For example, three photos are taken below with three different exposures. When combined, they show the range of brightnesses in the green arrow. That's a HDR photo.

Creating HDR Images

That’s great, but you’re probably wondering how they actually do it. The process isn’t as difficult as you might believe. All you need is a digital SLR and a tripod. You’ll also have to shoot all of your images in RAW format for this. The RAW format contains the data that Photoshop and other programs use to merge your series of images into an HDR image.

During your first shoot, you will want to choose a stable subject matter. There is a way to create HDR images for moving subjects, but it basically involves “faking it” with some pretty sophisticated Photoshop techniques. I cover these in the next tutorial. It’s best to stick with a more standard form of HDR photography for now.

Exposure Bracketing

Here’s another fancy term for you: exposure bracketing. This simply means taking more than one photo while moving the camera's range arrows around (setting different exposure levels). The more images you have in the bracket, the more professional your HDR photos will look.


EV -2

EV -1

EV 0
Normal Exposure

EV +1

EV +2

By now, you have your camera mounted on a tripod. You are ready to capture what will become you HDR image. Switch your camera to shutter priority mode and stay there.

Every digital SLR (and some point-and-shoot models) has a control for exposure bracketing. On my Nikon, this control can be found to the bottom right of the shutter button. When you hold this button down and slide wheel on the back of the camera, the exposure bracket changes.

Your first image will have an exposure bracket of zero. It will be the baseline for all of your other images. The value for this is also given in “E.V.” units. At zero E.V., your exposure is neither lighter or darker. At an E.V. of +1, your exposure is one bracket brighter. At an E.V. of -1, your exposure is one bracket darker. You get the general idea.

For the time being, I want you to take five separate shots, each at different E.V. levels. Take images at E.V. 0, +1, -1, +2, and -2. You shouldn’t have to adjust anything else once you adjust your exposure bracketing. The camera will automatically select a different shutter speed to give a lighter to darker exposure.

Don’t forget to take each image in RAW format! I am saying this again because I care about you. I don’t want you to go through all this trouble and have to go back out in the field because your forgot one small thing.

Once you’ve got your five images at different exposure levels, you’re done. Remember to name them according to their exposure level once you get home. This helps you keep everything organized. If you forget, it’s no big deal. You can always check the EXIF information on photo file.

We cover the Photoshop stitching in the next tutorial. We’ll also discuss ways to turn a single RAW image file into a HDR image when that’s all you have to work with. It's not normally as good as taking multiple shots, but comes in handy when you want to create an action HDR shot.

Until then, let me know how you’re progressing towards capturing your sequence of HDR images. I want to know what is working and what isn’t.

Most people think this post is Awesome. What do you think?

Comments

  1. George Jenner says:

    As clear an explanation as anyone could possibly want, David.Thank you.

  2. David Peterson says:

    @Mary,

    Actually, it doesn't matter if you are in shutter priority or aperture priority. The EV setting will always change the shutter speed. We don't want the aperture changing because that will change what's in focus on the image.

    David.

  3. Mary Shupe-Moore says:

    I'm a little confused by the instructions. Are you sure you mean Shutter mode? If I put my camera(D7000) on shutter mode,then I have to set the Shutter speed and the camera sets the Aperture, correct? Wouldn't it be better that I set the camera for Aperture and the camera selects the speed?
    Thanks!

  4. Nicole says:

    So, can you take pictures in the JPEG format, and make them HDR over photoshop, or do they have to be RAW?

  5. Wayne says:

    REad with great interest... Got sequenses of 5 Images.... Just waiting eagerly to see what comes next.

  6. kevinjung says:

    Thanks always.
    Back home last Jan. from Frankfurt German made me busy for settling in Seoul Korea.
    Now I can find room to take breath.
    Taking this chance, I would like to deliver my thanks to you for your kind answers to the questions others made, which have been a lot help.
    Thanks again

  7. Alastair M Seagroatt says:

    There's a great free program for the Mac HDRtist which makes life easy - I've used it with JPGs to great effect.

    I like trying to get the depth which HDR gives without it being obvious

  8. Rob says:

    Yes I also shoot with a Sony A550 asd it does a pretty good job of hand held HDR. More time at camera. Less time at computer. Good post though David..nice work.

  9. gopal says:

    thnx David so elaborately explaining the HDR process. i know many people are after it but i haven't yet tried.

  10. Mark says:

    My SONY Alpha A-550 has HDR as a built in camera feature. Once set up, the camera will take two exposures, one favoring highlights and one exposure for shadowed areas. The camera then processes the two images into one. This is done as a J-PEG. RAW recording is not capable in the HDR mode with this model, but perhaps with future products.

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