Step 1: taking the perfect shot

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Alan Townsend
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1 HDR MY WAY On demand of many people who like my way of making high dynamic range images from one single RAW file, I hereby present what I think is the best way to do it. For others that may very well not be true, and maybe what I do is blasphemy, who knows. The truth of the matter is that I couldn t care less, as long as I like what I produce. You will see that there s only one technical aspect I take into account in the whole process, and which is the basis of a good HDR image from one RAW file. The rest is just passion for photography, and desperately wanting to produce something worth looking at. Here we go: Step 1: taking the perfect shot Ah, the perfect shot. With the perfect shot, I don t mean perfect in composition. This is about HDR, so what you need, is as much detail in your image as you can possible get. In order to understand how to do that, you need to know where the information in an image is. For that, we will look at the histogram. If you divide it in five equal parts, no less than 75% of all the information in your image is in the two right hand fifths of your histogram. So, what you want to do, is push that histogram as far right as practically possible, without of course clipping your highlights. Anything more to the left means throwing detail, color, and light away. What I usually do to accomplish that, is measuring the light of the whole scene (matrix metering, that is), choose my aperture (typically f9-f11 for landscapes for instance) and then choose the shutter speed to make sure that I OVERexpose by 1 to 2 stops, depending on the contrast between shadows and highlights. And then I check my histogram of course. To make sure you got it right, just take some more shots with each time a faster shutter in between. One of those will be good to use. Your camera will tell you you overexposed terribly, but you didn t. Your camera is a chicken and thinks you re better safe than sorry, but you don t want that. Here s where I got that theory from, and believe me, it works:

Step 2:Generate the images for use in Photomatix And here s that disgustingly overexposed image I m working with: I have blown-out highlights and shadow

2 Step 2:Generate the images for use in Photomatix And here s that disgustingly overexposed image I m working with: I have blown-out highlights and shadow parts with no detail. Says Lightroom. Look at the histogram: ow what an enormous portion do I see on the right there! I bet you re tempted to do this now:

3 If you do that, don t come whining that you can t get a decent result afterwards, because you just threw away about 50% of the bits in the bucket. Yes, the image looks better now, but you don t want this image to look good, do you? You want a good HDR, so don t touch these sliders. Now, you want this image to be the lightest image to use for the HDR, so you export it. Then, you turn down exposure one stop at a time until you reach the point where you can see detail in the brightest parts of the image. I generated five images with exposure values from 0 to -4: See how nothing in the sky is actually clipped, although Lightroom told me otherwise. My camera told me even worse. There s some clipping around the sun, but that s what happens if the sun is still too bright. For me, it s no big deal. It s the same in real life, only there I bet you won t look into the sun like that.

4 Drag and drop the jpeg or tiff images in Photomatix en click the following button: When that s done, you get the following window: Just click OK

Next, since in the exif exposure values remain identical when generating several images from the same RAW file, Photomatix cannot determine exposure

5 Next, since in the exif exposure values remain identical when generating several images from the same RAW file, Photomatix cannot determine exposure intervals. You can either correct them, or just specify the interval yourself. If they all differ one stop from the previous one, it makes no difference what you do.

6 Next, you get this screen; You don t have to align source images, because they re the same anyway. If you work with multiple RAW files, you probably have to check that box and also the next one, if movement exists. However, this is not part of this explanation, so just click OK. After that, the HDR will be generated. It doesn t look very nice, because your screen cannot handle the huge dynamic range. This means we have to bring it down to the maximum range the screen can handle, and that in turn means you have to map your tones in order to generate a natural looking image.

I ve just taken a screenshot of the Detail Enhancer tab, which is the one with the most influence on

7 Evidently, you now click the Tone Mapping button, which brings us to the screen where you can tweak the image to suit your taste. I ve just taken a screenshot of the Detail Enhancer tab, which is the one with the most influence on your image. Below, you will find a brief explanation of what every option means and what it does, again according to my own experience. I haven t used the user manual for it.

8 Strength This value determines how strong contrast enhancements are. As for me, I tend to like a lot of contrast in sunset landscapes and in urban landscapes or old, decayed buildings. As these subjects are especially fit for HDR treatment, I tend to keep the value high. Color Saturation I don t really touch this slider a lot, unless saturation is a lot less than normal. Light Smoothing You have five possibilities here. The higher this value is, the more realistic the image will be. If you choose the value button on the far left, you get the unrealistic, obvious HDR images nobody really likes anyway. So, I mostly go for the far right button. Luminosity This value varies, and it just takes some sliding back and forth, until you get the feeling the image is pleasant to look at. Too high will generate noise and suppress a lot of the contrast you set with the Strength slider, and it will clip highlights, too low will wipe away the detail in the dark areas of your image. So I will look at the brightest parts of the image and go as high as possible, until you see that these bright parts start to lose detail. Then I go down again, until I see nice contrast, and detail in bright areas as well as dark areas. Tone white point, black point, gamma Don t touch it unless you know what you re doing. If you do experiment with them, take note of the initial values, because it will be hard to return to the original state once you ve thrown these values around. I adjust the White Point only if I have areas that are really still too light. Same for the Black Point in the dark areas. Gamma will just globally lighten or darken your image. In landscapes, it will appear as if contrast is enhanced in clouds and such. Color For finetuning the color temperature and saturation in highlights and shadows. I never use it, because I do these things in Photoshop afterwards. Micro This has a big impact on your HDR image. Micro contrast is all about how strong local contrast enhancements have to be. Sometimes you ll find they have to be strong, and sometimes not. As for me, I keep this value high. Up to you to determine how you like it. Micro-smoothing also has huge impact. High values will reduce local contrast, and ultimately give the appearance of overall contrast reduction. I mostly keep this value pretty low. S/H Highlights smoothing: a high value will smoothen out the highlights, which is not realistic. No smoothing will give hard contrast between dark and light, so keep it somewhere in the middle, at least that s what I do. Same for Shadows smoothing.

9 Shadows clipping: er I thought HDR was meant to make sure the image has detail everywhere. I keep this value at 0. All these values are in the detail enhancer tab. Next is the Tone Compressor tab, where you can adapt brightness, contrast and tonal range compression. I want nothing compressed, and brightness and contrast are fine if you got your settings right in the other tab. Then there s four more sliders: white point, black point, temperature and saturation. Well, I do all that in Photoshop when I process the image I got from Photomatix. So, now press Process, and there s your HDR. Save it under the name you want, and edit it in Photoshop if needed. My generated HDR from Photomatix and what I finally made of it can be found below.

10 Generated HDR: Final Result: This concludes my HDR workflow. Questions and remarks:

HIGH DYNAMIC RANGE IMAGING Nancy Clements Beasley, March 22, 2011

HIGH DYNAMIC RANGE IMAGING Nancy Clements Beasley, March 22, 2011 First - What Is Dynamic Range? Dynamic range is essentially about Luminance the range of brightness levels in a scene o From the darkest