Finally, a Beginner’s Guide to HDR

If you have ever noticed the photography of Trey Ratcliff, Click here, or other photography you have admired, you may have realized that much of the outstanding work done today is with H.D.R. photography. HDR stands for High Dynamic Range. It’s probably why you are interested in getting started on your own. If so, you are in the right place because about 15 minutes from now, you will be far more knowledgable than you are in this moment. Lets get started.

3 Sets of HDR exposures stitched together to make an HDR Panoramic

3 Sets of HDR exposures stitched together to make an HDR Panoramic

Theoretically, if the sensor in our cameras had the “range” of seeing shades of light as well as our eyes do, we may not ever need to pursue this, but cameras don’t. Brilliant programmers working with Photographers have created software for “merging” images together keeping the dark parts of some and the light parts of others, creating a single image with both light and dark parts in one image.

That’s HDR. If I could explain it yet a slightly different way, I would say that HDR photos are very much what the photographer “saw” when he snapped the shutter. At first, when experimenting with HDR, you can get decent results but GREAT results come over time after you’ve learned how the HDR process works.

Knowing how HDR works lets you “pre-visualize” a final image. It’s because you know what will happen when you combine these images, you can select places to photograph which will let you express yourself even more so with this tool. Not all my images are HDR and while many daytime images are, there are many that are just not appropriate to be processed in that way. Besides talent, the best photographers have options. I want to give you one more option for making a great photograph.

 How To Take Photos In Preparation for HDR Processing

Before getting into this part, I want to make sure you are using a strong, steady tripod. While it’s possible to shoot HDR hand held with enough light, I highly recommend a good tripod to keep your camera from introducing shake. The tripod I use is the Gitzo Traveler which you will never be sorry you bought.

Because you are capturing detail in either the extreme of darkness or lightness (highlight area) your camera needs to think those areas are in the middle of the exposure range. For those familiar with the zone system, we want to move the brightest area of the image closer to Zone 5 or the middle of the exposure band. This middle band can be easily illustrated by looking at the histogram display available on most cameras. If you are starting to yawn about now, lets take a look at this histogram below, and then I promise, we can forget about it.

Histogram shows over exposed image

Histogram shows over exposed image

This image is courtesy of www.RonBigelow.com who does an outstanding job of explaining histograms in detail. I wanted to just touch on this so you are familiar with how histograms relate to HDR photography.

Notice how the graph is all crowded up against the right side of the graph. That would tell you that there’s too much light in this image, the sensor can’t handle all that light and the photo will look mostly white, as you can see in the photograph beside it. As we reduce exposure, we darken the image and move the “peaks” to the center of the graph. Yet, in this case the dark areas in this photo have lots of detail, which you want when creating the over exposed frame in an HDR set. The set consists of at least 3 exposures.

Making the Exposures

You need at least 3 exposures of which one is perfectly exposed in the middle, as the camera would want to take if set on Auto. The other two are under exposed and over exposed by 2 stops each. If you have an auto-bracket feature on your camera, you would set that up so you can take all 3 images with one shutter click.

 How to Set Up Your Camera

Programming the Camera for Auto Exposure Bracketing

Programming the Camera for Auto Exposure Bracketing

This is the display of a Canon SLR, which indicates that Auto Exposure Bracketing is engaged and that the camera will take 3 photos; one stop under, one stop over and one image exposed as the camera thinks it should.

Top of Camera shows 3 exposures

Top of Camera shows 3 exposures

 

Also notice that it says “Exposure comp./AEB setting” on the display (above,) just to remind you what the camera is programmed to do. Are you still with me? Do you think this is too complicated yet? If you do, then the next part will help.

Just to make sure you are getting the visual representation of one stop over, one stop under and one in the middle, the top camera display shows three vertical lines at -1, 1 and 1 (just under the battery image) and it shows the three frame visual circled in RED. Now you are ready to go out and make a series of photos, each one composed of 3 different exposures!

If we made those 3 exposures properly, they would look like this:

Example of a 3 exposure HDR set with the final result

Example of a 3 exposure HDR set with the final result

In this example, we used the 1st image underexposed to capture sky detail which was mostly absent in the middle exposure. The 2nd (middle) image, being the average exposure captures the middle tones just like we expected. The 3rd image is overexposed and captures detail in the shadow area by overexposing the whole image and bringing the shadow area up into the “normal” band. The 4th image is what happens when you combine the best of all three to deliver what I truly saw when I looked out at that ocean. I did edit the final image a little but it’s mostly a combination of the three. Some cameras can take as many as 7 exposures with one click, bracketing by 1 stop or less. I have been experimenting with 5 exposures using the Canon 5D MkIII and its working well.

 Lets Review 

So far, we should understand that an HDR photo is a combination of 3, 5 or 7 separate photos, each one exposed for a different range of light. That means we set up our camera to make a series photos in a row, with the only difference being the the amount of exposure we give each photo. Tip: Never vary the aperture, only the shutter speed, which will insure the combined photo has the same plane of focus as each one separately.  If you’ve followed me so far, you know how to make the minimum 3 exposures, either manually or with your Auto Exposure Bracket feature on your camera. Now, the next step is to combine them into one dynamic image, that expresses what you saw when you made those multiple exposures.

Combining Images for a Final HDR Photograph

In a sense, there’s really nothing too complicated about combining the three images together but as you will see in a moment, that’s just part of the job. A well designed HDR software program should also remove “ghosts” which are images that appear on one but not all of the exposures you made. If a person is walking through your scene, this could produce ghosting. HDR software will reduce ghosting.

If you shoot your exposures by hand, there will be a small alignment problem with each of the exposures. If the alignment issues are really small, those too can be corrected. And finally there are “chromatic” or color variances between frames, which the software should correct too.

Finally, there’s the task of actually editing the combined image to make it dynamic and exciting, part of that work is done by the HDR software too. It’s called “Tone Mapping” and it’s all about making sure the image looks like you want it to look. Tone mapping can make your image look surreal or realistic or somewhere in between, you get to choose.

Watch my screencast to see how I import those images into HDR software and produce a final image: Click Here to watch, but come back after the video is over. You will see step by step how to take those bracketed images and get the into HDR software.

This is the finished image after a little touch up and cropping. It’s very easy to start making HDR images that improve your photographs quite quickly.

HDR Snowstorm Feb 9 2013

HDR Snowstorm Feb 9 2013

I hope this was helpful, I have a few other resources I could recommend if you wanted to dig a little deeper into the world of HDR photography.

There’s a book I really like and it’s perfect for beginners: Creating HDR Photos; The Complete Guide. It’s under $20.00.

The software I use to process my HDR images is Photomatix Pro 4, which is the most versatile of the bunch. Other companies offer HRD software but I still return to Photomatix when I want to get the job done.

If you want to really learn from the master of this topic, I highly recommend Trey’s course Click here for description which is comprehensive in every respect. I have taken this course and found it to be outstanding. My blog post today is an introduction, something you should be able to use for starting with HDR. It’s a topic you can spend many hours learning about but the best way is to go out an use your camera!

And finally, if you want to immerse yourself for several days at a time, there are photographic workshops that take you to magical places where you can spend intensive time in both travel photography and instruction.  If you have an interest in traveling with me on my next adventure (my last trip was to Iceland, before that it was Jordan) then let me know.