Monthly Archives: September 2010

HDR Lesson – How do I know if the scene is a good candidate for HDR?

How do I know if the scene is a good candidate for HDR?

This is a great question and one that is probably rarely asked. Not every scene in front of us is a good candidate and really if the Dynamic Range of the scene before us is not wider than the dynamic range of a standard image out of our cameras, we really shouldn’t use HDR. Not that you can’t but it really has no purpose and will in the end not look better.

So what is an easy way to determine if there is an excess of dynamic range that we need to switch over to using the HDR process?

 It’s generally accepted ( and argued) that the Human Eye is capable of  seeing a Dynamic range of about 24 f Stops (1 stop is the halving or doubling of light) But that is with the iris adjusting to the light. In one view, the eye is capable of about 10- 14 stops. In theory a high quality camera shot in RAW has a Dynamic range of about 11 stops, but in practice it is really closer to 6-8 stops. A print from that camera is capable of about 5 stops.

But the truth is, I’m not very good at science or math and I don’t want to be pulling out My Texas Instrument calculator or my slide rule and figuring this all out when I am shooting. In fact I really hate even having to think when I shoot. So what is an easy way to determine if the scene before you has enough dynamic range to make it worth the time to set-up and shoot an HDR Image?

We’ll use our meter

Take your camera and set it to manual exposure. Now set the metering mode to either spot or partial. These  are the most precise modes for measuring a small area of your viewfinder. Point your focus point (which also is your meter point) on the brightest area of the scene and adjust your exposure so that it registers +2 on your meter. Now move that meter point over the darkest area of the scene. If the meter hits or pegs past the -2 point, there is enough dynamic range to do an HDR. If your meter reads anywhere in between. There is no need to do an HDR.

Now let me give you one important note on here because I don’t want anyone looking into or pointing their camera directly at the sun and damaging either their eyes or their camera or BOTH!! . IF THE SUN IS IN THE FRAME OF THE IMAGE IMAGE, there is more then enough  Dynamic Range to shoot, Done, Game over, don’t even need to check.

Here are two examples so you can see what I mean from my backyard.

In this image, the light of the scene was very flat and really not much dynamic range. When I measured as above I only got about 1.5 f stops of change from the brightest area to the darkest

Metering for HDR

So this would not be a good candidate to shoot HDR.

But I still made one to show you, It doesn’t look better in fact it look flatter than the standard image above

HDR Poor Dynamic Range

Now the next morning, I had this scene in front of me as the sun rose.

Dynamic Range

As you can see the Dynamic Range is about 6 Stops ( It’s actually closer to 10 total but we won’t go there for now) and it really doesn’t make a good Standard Image at all. The sky is blown out and  shadow areas are too dark and into the noise floor of the image.

Here is a 5 shot HDR of the same scene, as you can see, this one was definitely a candidate for HDR and gave us more of what our eyes would see at that time of morning.

5 shot HDR

Hope that helps!

P

The State of the Art – HDR

The State of the Art – HDR

I hate HDR images! Whoa what? You have a website devoted to HDR images and you hate them? Yeah, well, kinda, I hate what has become the De facto standard for “That HDR Look”. Well hate is too powerful; I dislike them, for the most part.

HDR is a fairly new technology and whenever something new comes out people are not quite sure what to do with it. Let’s look back at another new technology that came out over 50 years ago. Stereo sound recordings. Before them everything was presented in Monophonic or just one speaker. Well we all know if we were listening to 4 musicians play, it would not sound like they were all playing from one spot. We might hear a guitar on our left, another on our right, the drums and the bass may be in the middle in front of us.

Then came stereo. Now the original purpose of stereo was to recreate more closely what it sounded like if we had musicians right in front of us playing and to recreate that soundstage. But because it was a new technology and there also was not enough other technology behind it to do it correctly, people didn’t know what to do with it and ended up doing things that really didn’t fit with the original purpose or mission.

Even the Beatles and their great producer George Martin didn’t quite know what to do. So some of their earliest attempts at Stereo put the instruments in one channel and the vocals on the other. Not really giving the effect at all that the musicians were playing in front of you. In fact George Martin hated the sound of these so much that many years later when he was remastering those albums for release on CD, he made them all in Monophonic because he knew that the stereo of that time was just wrong.

So what does this all have to do with HDR? I think the same thing has happened here. People don’t know what to do with HDRs and some things that aren’t really the original purpose or mission of HDR are become the standard for the “HDR look”.

So what is the original purpose or mission of HDR? Well, of course this is my opinion; we are trying to make a photograph that more closely resembles what we see in real life. And because the Dynamic Range of our eyes are much wider than a camera’s we can’t do that with conventional photographs, when photographing a scene that is wider than our camera is capable of capturing. Scenes that are not that wide in dynamic range are captured quite well using standard photography.

Here is an example of what I mean, it may be a little exaggerated but honestly it is not beyond what I have seen in HDR examples.

Bad HDR

So I was there, I took the photograph. Is this what I saw? Did I see the deep dark gray scowly clouds? Did I see bright insets on the tower? Did I see haloing around areas of contrast around the buildings and trees? Did I see a mostly mid-toned scene or did I see one with full range from dark to light? Did it look CGI (Computer Generated Image)?

My answer would be no. But I still could get people to look at the above and go,”Coool!” because it was different and well what is expected from HDR these days.

However, I also had a lot of my photographer friends say to me when I told them I do HDR. “Oh, I hate HDR” I would reply, “Have you seen mine”, “No.”

Well here, look.

Good HDR

Most people would then say, I don’t like HDRs but I like yours. This example is more like what my eyes saw that day, White clouds, consistent tone to the building, no halo. Full range from dark to light. I’ve more closely recreated what I saw that day.

Is it perfect? Probably not. We really don’t have a great memory from things we see, our sense of smell is actually much better at remembering things. I also tend to go a little over on color saturation because the Buying public like it. Is that right? No, but I like making money too. So will I say is this  exact? No, but it’s close.

Now because I believe in art and artistry, let me say this: If the first image or one like it is your “Artistic Intent”. It’s what you intended, then I am all for it. Go do it! But if it is because you “thought” that was the way it should be. Because you saw other examples of HDR that looked like it by  even by some of the biggest proponents and originators of HDR . Or if you just didn’t know any better… then no, it’s not what the “State of the Art”  HDR should be.

Hello world! Welcome to the HDR Image

Hi everyone! Welcome to The HDR Image. High Dynamic Range as it should be.

Here I will show examples of my work in HDRI ( High Dynamic Range Imagery), show you some How To’s and talk about all things HDR. I hope you enjoy this and maybe learn a few things and most of all have fun with a new and exciting tool to add to your photography.

One note, If you came here to look for or discuss the science of this all you probably came to the wrong place. I’m not a scientist, nor a mathematician. I’m a photographer. Could I understand and follow a conversation about the it? Sure, but I don’t want to. It bores me to tears as it does many photographers that are more artist than technicians.

So even though there is a lot of technology to this, I’m not going into all the numbers and have people turn off and click off. It will be in the most simplest terms I know how to present and how most of my student like to learn.

If you are interested in the tech, I would point you to  Cambridge  in Colour Really a great read

Peter