Monday, July 19, 2010

My First "HDR"

For those of you not familiar with the acronym "HDR", it stands for "High Dynamic Range".  It is a process by where you can merge multiple exposures of an image together in order to properly expose drastically different areas of an image by bring out the details in shadow areas, toning down the highlights in overly exposed areas, etc.  It's often also associated with a process called "Tone Mapping" which allows you to "amp up" the color saturation into what I call hyper-realistic images.  In the photography world, the HDR topic seems to be one of great debate as most people fall into either the love it or hate it category.  Personally, I like some of the hyper-realistic images, but tend to lean toward the more natural look in most cases.
While on vacation a few weeks ago, my wife and I arrived at the tail end of an amazing sunset among a crowd of other shutterbugs.  While I snapped off a fair number of shots, I admit that I didn't take the time to employ such techniques as "fill flash" to capture the exposure I was really after.  Like I said, the light show was pretty much over and time was of the essence.  I found some nice foreground subjects in a pair of Adirondack chairs, but as you'll see from the original image below, the exposure was pretty dark against the sunset.

The tripod mounted exposure was taken at ISO 100, 95mm, f/22 for 0.8 seconds. Let me point out the sensor dust now as it will be the topic of discussion for tomorrow's post.  See the little "pepper-like" spots in the upper left corner and again above the tree line near the center of the image?  Yep, that's what a dirty sensor does to your images.  More on that tomorrow.
Through the magic of Lightroom 3, I was able to remove the dust spots and adjust the exposure to improve the photo a fair amount.  Remember the post on file formats?  THIS is why you want to shoot in RAW format.  It provides you a fair amount of room to maneuver in post processing with the additional information that's captured in the RAW format.  Here is the same image after my Lightroom adjustments...

You can see I removed the sensor dust spots (and a few other distractions), used some fill light to bring the exposure of the chairs up some and you can start to see that the grass is actually green.  In truth, I really wanted more fill light as it did wonders for the foreground, but the more fill light I added, the more noticeable the nasty halo I was getting around the silhouette of the bluff on the left.  After exhausting my bag of tricks I still wasn't where I wanted to be with this photo.  This is when I decided I'd been putting off the HDR thing for about as long as I could and it was time to give it a try.
I mentioned that HDR combines multiple exposures.  Ideally, you would have used auto bracketing to produce 3 or more exposures (I don't have auto bracketing on my D40x so it would have been a manual process).  Well, there's my first problem.  I only had one exposure of this scene.  What to do?  I decided to make two "virtual copies" of the image in Lightroom 3 and then exposed 1 of those copies under (EV -2) and 1 copy over (EV +2) so in total I had 3 exposures to use. My wife had been playing with a trial of HDR Soft's Photomatix and decided that it was something she had a use for and I'd read enough about it to know that it was one of the most widely used applications for HDR processing.  After applying yet another discount from my NAPP membership (I'm telling you it's worth the price of admission :), we were the proud owners of Photomatix Pro.
Here is the HDR output of the 3 exposures after being processed through Photomatix Pro using the "natural" preset (and a few more tweaks in Lightroom).

The foreground is now where I wanted it to be, we're just starting to pull out a little detail in the bluff to the left and the sky is still more or less intact with the beautiful sunset.  This is much closer to what you would have seen with your own eyes had you been there.
So there you have it - my first HDR!  I'll be the first to admit that I have a lot more to learn when it comes to utilizing Photomatix Pro, but for my first attempt I'm rather pleased with the results.  I'd love to hear your feedback.  What do you think?


Snezana said...

Amazing. Wow.

Anonymous said...

I'm sure a lot of people don't the full form of HDR. So, thanks for describing it nicely. Anyway, my first HDR camera is Nikon D5500, just bought it last year. It's a good camera and takes high quality pictures.

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