Demystifying Photo Techniques: HDR: Part 1: The Awakening

Photography is an interesting business, here in the age where everyone has a camera the perceived value of our services has gone down, simply by the amount of supply that has been offered – mainly by friends and relatives with a camera.  There are a few ways to overcome this; you can quit, or you can find a way to show potential clients why your experience is worth the price.  I choose the latter, using a variety of techniques while shooting as well as processing to do things your average photographer can’t do, or doesn’t use to their advantage.  And so begins part 1 of what will be hopefully at least a 2 part series: Demystifying Photo Techniques: HDR: Part 1: The Awakening.

What is HDR, and why do I care?

HDR may be old hat to a lot of photographers by now, but it is just starting to become mainstream, it’s a stock filter in Photoshop as well as a feature on your iPhone, but what is it exactly?  A lot of folks either think HDR is a magic device that “makes your photos look more prettier”, or a device that renders normal scenes into cartoonish, super-saturated shells of their former selves.  While it does do both of those things it can also do so much more.

By definition, HDR stands for High Dynamic Range, dynamic range meaning the difference between the lightest part (before hitting pure white) and darkest part (before hitting pure black) in your photo.

In digital photography, light is measured in levels from 0-255, 0 being black and 255 being white. This is represented in most software by a histogram.

This is a histogram, it looks like a mountain.

The leftmost part of the graph represents 0, the rightmost part represents 255.  The more there is of any one value, the taller of a line it is. The histogram from the above photo has a lot of dark tones in it, so it is more heavily weighted on the left.  It is also an example of a photo that wouldn’t benefit that much from the use of HDR.  “Why is that, Nathan?” you may ask.  Well dear reader, you are in luck as I happen to have an answer for you after the break.

 

 

OK, Now I know what HDR is, but why is it useful to me?

Welcome back reader, and good question, you are an astute student. One of the main reasons to use HDR is because you cannot capture all of the tones in the image in one photo.  A histogram that would benefit from HDR would look something like this.

This one's more of a valley.

As you can see, there are a lot of tones on both ends of the spectrum, indicating that in this photo both highlights and shadows are being cut off.  Once these values have been clipped, there isn’t really a way to bring them back.  They get sent to the land of lost socks and old cell phone batteries, never to return.  This is where HDR comes in.

By taking photos at different exposures, you can effectively capture all the possible tones of a scene.  An example of this is shown here.

 

I'm pretty sure this is right side up...

 

OK, that seems legit, but how does it work?

This is a photo I took in Jasper at the Mount Edith-Cavalle ice caves.  It is quite dark in the cave, and when I took the initial exposure, the inside of the cave was black except for the highlights on the ice and the outside was pretty much blown out  white.  When I changed the exposure to regain some of the detail of the exterior, the interior went into the land of the lost socks; I had lost all detail in the inside of the cave.  When I exposed for the interior of the cave, the exterior became so bright it was affecting the detail inside the cave.  Alas, if only I could have the best of both worlds!  Boom, HDR to the rescue.

 

I figure it's not copyright infringement without the head, right?

 

I took 5 exposures, one so dark that the highlights no longer were blown out, and one so light that the shadows were no longer clipped.  This turned out to be 10 exposures apart, so I then took 3 more shots in the middle to allow me the maximum amount of detail in the shot.

That’s great and all, but you still didn’t answer my previous question, HOW does it work?

Fine, if you’ve put up with my rambling this far you deserve an explanation.  Without going into algorithms and a whole heap of technical jargon, HDR essentially takes the tones from all the photos and compresses it into a usable dynamic range.  It takes the highlights from the dark photos and the shadows from the light photos. You literally get the best of both worlds.

Where one world is a lake.

And the other is a barn.

Well that seems great.  Why shouldn’t I use it all the time?

Like most trends, HDR does get its fair share of criticism. This mostly seems to stem from overuse, as well as improper use. It often gets used for more of a look than a tool to remedy a problem.  Most HDR programs allow you to make an HDR toned photo out of one image, where it expands the dynamic range artificially and then compresses it as if it were a real HDR.  This can create the look of an HDR image, but it is not a true HDR by definition.  The main problem people are having with HDR is that it makes such a dramatic change in the photo that it seems to be used as a crutch.  You should never sacrifice composition or subject for the sake of saving it with an HDR treatment.  It’s tempting, but it is also morally and ethically wrong.  Your mother would be disappointed.

You didn’t need to bring my mother into this article, that was unnecessary.

I’m sorry, it was uncalled for, here is a list of HDR programs for you as part of my apology.

PC/Mac:

Photomatix – $45.95

Artizen HDR – $44.95

Picturenaut – FREE

Luminance HDR – FREE

 

iPhone/Android:

ProHDR – $1.99

Dynamic Light – $0.99

Next time on Demystified Photo Techniques, we will either tackle tilt-shift (miniature) photography or photos of cats, I haven’t really decided yet.  Actually, since I called this part 1, I assume that means I’ll have to do a part 2… So next time on DPT, we will have HDR: Part 2: The Tutorialing.

If you have any questions regarding HDR photography, send me an email at nathan@purevisioninc.com and I would be happy to help you out!

 

Leave a Reply

Your email address will not be published. Required fields are marked *