HDR Tutorial

 

Welcome to my HDR tutorial. Below I’ll explain the basics of HDR photography to allow you to produce HDR images in no time. In the future I’ll be making e-books available containing some more advanced techniques. If you’ve got any questions or problems feel free to ask them in the comment section below or e-mail me: johnnyp@traverseearth.com. I’ll be updating this tutorial periodically to try to clear up any confusing points that become evident from your questions, so go ahead and ask!

What is HDR?

HDR is short for “High Dynamic Range”. The human eye is capable of seeing a very wide range of light intensities. This is considerably wider than is possible with current digital camera sensors. This is why photographers must make compromises in creating an image. Often a choice has to be made to lose details in shadows and/or highlights because it is not possible for the sensor to pick up on both in one exposure. However, by applying HDR techniques it is possible to increase the range of light. This reduces the level of compromise that must be made and can result in images that, in my opinion, better capture the scene.

Why HDR?

I discovered HDR as a direct result of upgrading my camera gear. It didn’t seem right using my old Cokin filters on my brand new L series lenses. I was researching which filters to buy and decided to find out if I really needed them. I’m not sure how, but as a result of this I found that the HDR method captures the full light range of a scene. This means that there’s no need for graduated filters. I’d been using them for years, and they’re seriously fiddly and force you to carry more gear.

Additionally, I always felt like I was struggling to portray depth in my photographs. It didn’t take long experimenting with HDR to realize that this allows you to produce images that feel like you could step into.

Along with this amazing ability to portray depth in an image the level of detail captured in HDR images is incredible.

The end result is that, I feel, you can better portray reality using HDR.

What You Need

  • A camera
    • In order to create HDR images you need a camera that allows you to adjust your exposure levels to produce a range of photos that capture the full light range of the scene. Ideally your camera will also have an auto bracketing feature. When this is set it will capture multiple exposures automatically.
  • A tripod
    • You can create HDR images without a tripod and I shoot handheld when I need to (such as when I was in a canoe on the Lower Zambezi, or riding on the back of an elephant). However, when it comes to processing it’s much easier if you’ve used a tripod as you won’t need to mess around with aligning the images as much. Also, tripods make for better pictures whether working in HDR or not. They force you to take your time and really think about the composition of your photo while increasing the sharpness of the image.
  • Photomatix Pro (You can get 15% off this product by using this coupon code: “TraverseEarth”)
    • This software takes your photos and merges them into an HDR image. It then requires your input to tone-map the result.
  • Photoshop
    • As you’ll see below one of the key steps in creating a realistic HDR image is using layers to mask back in areas of the original photos.
  • Topaz adjust (Optional)
    • You can get away with just using Photomatix and Photoshop to produce HDR images but Topaz Adjust really is a great plugin. It allows me to really crank up the level of detail in my images.
  • Noiseware Pro (Optional)
    • I say this is optional, but the HDR process tends to result in areas of the image with a lot of noise. This program is great for smoothing it out.

Taking Photos

The following will provide a step by step guide on how you need to set up your camera to capture bracketed images to combine into a single HDR image. I use a Canon 5d Mk II so the details will be based on this camera. I expect it will be the same or similar to most Canon DSLR that share the same features used here.

  1. Set camera to aperture priority mode. You need to shoot in aperture priority so that the depth of field will stay the same for your various exposures. The camera will change the exposure by increasing and decreasing the shutter speed rather than changing the aperture.  If you were to prioritize shutter speed the aperture would change. This means that each photo would have varying amounts of the image in focus. I typically stop my aperture down as much as possible in order to get the largest depth of field I can. One of the features of HDR that I really like is the ability to capture a huge amount of detail, this would be lost if these areas of enhanced detail were out of focus. That being said there will always be scenes that benefit from a narrow depth of field. You can produce HDR images at any aperture setting.
  2.  Turn on auto-bracketing. When shooting handheld I set my camera to automatically capture 3 images. The first image is at the “correct” exposure for the scene. The second I underexpose by 2 stops and the third is overexposed by 2 stops. I do my best to use my tripod whenever I can. Typically, when shooting on a tripod I’ll take 7 exposures. You don’t always need to take 7 exposures and the more  HDR photos you produce the better you’ll get at telling what you need to capture the full light range of a scene. I’m still getting the hang of this so take 7 exposures to stay on the safe side. With the Canon 5d mk II it’s not possible to automatically shoot 7 exposures. So, first I’ll set the auto-bracketing to capture -3, -2, and -1 exposures before setting it to take +1, +2, and +3. Then I finish off with the regular exposure. This works quite well and as you get used to your camera it becomes very easy to change these settings quickly. The only problem is that you have to touch your camera between shots to do this. This inevitably results in the camera moving slightly so the resulting images need to be lined up in Photoshop.
  3.  Set your ISO. The post processing involved in producing HDR tends to result in a lot of noise in the resulting images. As you’ll see below this can be cleaned up. However, it is important to ensure that the original images have as little noise as possible. This means using the lowest ISO that you can.
  4.  Set your drive mode. This is really useful. When shooting handheld you’ll want to set it to continuous shooting. This way when you hold down the button it will fire off your three bracketed photos. When shooting on a tripod you’ll want to set this to the self-timer mode. This is so that there is a pause after you press the shutter button before the photo is taken. This prevents any camera shake resulting from you pressing the shutter button. I have my camera set to a 2-sec self-timer.
  5.  Push the Shutter Button. The last and ever so important step. Remember to take off your lens cap too.

Photo Processing

I’m going to break this into three sections. The first being aligning the bracketed images, the second being combining and tone-mapping the images in Photomatix, and then returning to Photoshop to clean up the tone-mapped image.

Aligning Images:

Originally, if I had used a tripod I didn’t think that I needed to align the resulting images. However, I’ve discovered that they’re always a tiny bit out, particularly when I shoot 7 exposures as I need to touch the camera to adjust the settings between groups of shots.

In order to achieve this, I use Photoshop. Photomatix (next step) does have an auto-align option but I read somewhere that Photoshop’s alignment abilities are superior. Whether or not this is true I don’t know, I always felt that Photomatix was aligning the images just fine. The reason that I use Photoshop to align my images is that it makes it much easier when you want to stack all the images, including your tone-mapped image. If you use Photomatix’s alignment feature your tone-mapped result will not align with your original exposures, which can be a real pain.

So, to align your images do the following:

  1. Open images in Photoshop
  2. Select: File > Scripts > Load Files Into Stack…
  3. Click “Add Open Files” and check the “Attempt to automatically align source images” box.
  4. Click “OK”
  5. Wallah!! You’re images are aligned, but there will be bits of white around the edges you’ll want to remove. To do this, the best method is to select: Image > Canvas Size… Reduce the height and width to 99 percent.
  6. Export the layers into individual files by selecting File > Scripts > Export Layers to Files…

I like to export my files to a scratch file I can clear out once I have finished processing the image.

Once you’ve got the images aligned and saved you can move on to combining the exposures in Photomatix.

Click here to move on to page 2 of the HDR tutorial.

 

 

  2 Responses to “HDR Tutorial”

  1. Yes please! Gotta get on it Johnny!

  2. Hi,

    I’m taking part in your contest. I love your website and would like to have the tutorial!

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