HDR Confusion

I had spoken briefly on the topic of HDR imaging my last blog. A few peers I know were concerned that I was speaking in general – that HDR is the only way to photograph. Not so.

Today, I’m here to clear up the confusion.

I think the introduction of the digital age has been a tremendous help to photography and photographers. Think back twenty years ago. When you exposed a negative (or positive) it took hours (if you processed it yourself) or it could take several days (Kodachrome comes to mind) to see the results. Now, right after the shutter is released, we get immediate feedback on our efforts.

High Dynamic Range (Imaging) isn’t new to the scene. Sources that I have found date it back to the mid-nineteenth century. Most sources I have found point back to a French painter who found photography (specifically the calotype) to be a method of expression. He would use two separate negatives – one exposed for the sky, a second exposed for the landscape and combine them into one positive print. Today we’ve taken it to the next level at the advent of the digital age. Today most cameras have built in the ability to create an HDR image or we can use auto-exposure bracketing.

When I first discovered HDR exposure bracketing I found it very useful. I was photographing scenes that had an extreme in dynamic range. At least fifteen stops (EV) of light difference. I could tell that the ratio of light to dark was far more than one single image to interpret. What’s more, I used to try to force detail though hours of manipulation in Adobe Lightroom/Photoshop with that one image. So, finding out about HDR was a pleasant surprise.

Then, as my bend on life, I took it overboard. I was using exposure bracketing on everything. But I was starting to see a difference in my images. The color was terrific, so much I’d need to bump down the saturation (desaturate) to get the image the way I saw it. But the shadows were full, and the highlights were under control.  The only difficulty was my black and white conversions weren’t lining up with my Zone System training. It was all wrong! Then my peer (and photographic mentor) Gary Pedersen mentioned that he’d experience the same results. For Gary the solution was to separate each color layer, perform an adjustment on each three separately and then overlay them to get the black & white image of his desired pre-visualization.

A moment with Gary Pedersen. Gary and I attended Utah State University at the same time. We were both art majors, both graduated with a Bachelor of Fine Arts degree and we both took our art seriously. But maybe Gary more so than I. Gary arrived at art school with a Hasselblad medium format camera. Me? I was still trying to make it work with that Minolta camera I mentioned in my introduction. By the time I’d scratched together enough money to buy the Graflex XL, Gary was using a 4×5 view camera. But he didn’t stop there – for graduate school (MFA) he’d progressed to a massive 8×10 view camera he used for making carbon prints. Gary doesn’t do anything small.

Anyway, his color layer separation was more labor intensive that I desired. I wanted it fixed. Right. Now. But I couldn’t come up with a good solution that worked every time. That’s when it dawned on me – maybe HDR wasn’t the silver bullet I’d been hoping for. Could there be times when HDR wasn’t desirable? My answer slowly turned to a “yes.”

There are times when HDR is the only solution. If you’ve been a photographer for very long, you’ve come to that same conclusion. Some scenes are not suited to HDR. The three, five or seven exposures just are a waste of time.

Example #1 & 2 are prime examples of not needing to use HDR. It was an overcast day, in an evergreen forest with just a hint of the overcast sky peeking through the treetops.

Example #1
Single Image (N)

Example #2
Five exposure HDR merge of the same scene

Easy enough to see, there isn’t a whole lot of difference between the two. The scene before me simply didn’t hold the dynamic range to fully exploit the advantages of HDR imaging. To be certain there are differences – but too slight to really justify the five exposures I took to create the HDR version.

In examples #3 & 4 we see a different scenario before us. It was just past daybreak. I was out in the same woods looking for a decent sunrise shot. I missed the actual sunrise, but I did capture this one as the sun crested over the tree line. It was quite the sight, and I could tell something good was going to come from this.

Example #3 Sunrise (N)

As we can see in example 3, this was a single exposure. The camera setting was aperture priority. 1/125th sec @ f/11. ISO 200. Nikon D3. NIKKOR 24-120mm f/3.5 shot at 24mm. The metering was pattern, so it took a heavy bias towards the cresting sun. Obviously, it is extremely under-exposed. I rarely, this might have been the only time, point my lens directly into the sun. But, in this case, my eye saw a completely different scene. Working with this image alone, I was able to get make it a decent print (see example 3a) but it still wasn’t what I was envisioning as the final product.

Example #3a – single exposure image
adjusted through Adobe Lightroom

As you can tell example 3a, it isn’t a terrible image. But at my level of photography knowledge and experience, this is a not a successful attempt at creating art.

Example 4 is more what I was seeing through the viewfinder. Knowing that the dynamic range was far greater than one exposure could handle, I decided to use the exposure bracketing method. I decided that a three exposure varied by two stops (shutter speed not aperture) should cover the gap between the dark values and the highlight values.

Example #4 – a three exposure (-2, N, +2) bracketed HDR
Spot healing done in Adobe Photoshop & lightened overall by 1/2 stop

The 3 exposure HDR turns out a much more pleasing, more detail revealing image. In retrospect I could have gone as far as a five stop HDR on this scene. It required some exposure manipulation in Adobe Photoshop to get it just right This is closer to the scene that I was moved by before I tripped the shutter. I did some spot healing, there was plenty of lens flare – which I fully expected. The ground is fully visible as are the details in all the trees. You could call the sun a little hot, but that burst was exactly what I was wanting to create, so a hot sun is acceptable for me.

Example #5
No adjustments or spot healing

Example #5 shows what Adobe Lightroom did on its own. Not bad. Example #4 is a better final image. In #4 you can make out the foreground, the trees and vegetation are visible, and we are starting to see detail in some of the trees. Plus, the highlights aren’t wrapping around the tree branches.

I want to stress, when deciding on whether to use the HDR technique, look around. If the dynamic range is excessive, you probably would be better suited to use the three-exposure method. If I do use the 3-exposure method (-2, N, +2) Adobe advised to leave the normal exposure out (to lessen the merge time) but they say to throw in as it might help some. For me, if I take the time to expose three images; I’m going to use three images. Test this for yourself. There have been times when I’ve taken as many as seven exposures to cover the range. Good luck out there.

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