Amateurs Guide to HDR Photography

I will try, in my ignorance as a beginner on this topic, a small tutorial or explanation of what are photos HDR and how they can do the necessary means and their preparation. First understand what they are photographs HDR.

The HDR is an acronym for “High Dynamic Range” (High Dynamic Range), although the full name of this technology is “High dynamic range rendering” or HDRR (High Dynamic Range Rendering). This rendering technology mimics the functioning of the iris in the human eye. The human eye adapts on a continuous basis and with great effectiveness to different luminosities of the same scene as opening or closing the iris while integrating all the information is captured in the brain. Thus this body is able to clearly see a scene with areas with different lighting.

The cameras do not have that ability to adapt and what they do through the photometer (light meter) is taking an average of the different areas and make photography with this so that some areas may be well lit but expense of others are too dark and other white.

Then, using techniques HDR seeks remedy this defect in the photograph getting properly illuminate all its areas anuque containing “quantities of light” very different.

What materials do I need?

The HDR photographs can be obtained in several ways. Because what we are trying to achieve is to simulate this adaptation is our view that to achieve integrated takes a different luminosities, the interesting thing will take several pictures with different compensation lighting, so then treat them digitally. In other words, the camera perform several different shots by adjusting the lighting.

There are ways to create photographs HDR from a single image. Some digital cameras have the ability to generate images in RAW format, an image format that does not compress the resulting file and therefore not at all degrades the quality of the photograph. From a single photograph could also generate an HDR simulating different light compensation, but obviously think that is better than the information that has to generate an HDR is real, from 3 or more photographs with various exhibitions, that one-in which he simulated these exhibitions.

Even some technical talk about how to generate HDR from a single photograph in JPG, the general format with the cameras that carry out the pictures, but most still think it seems obvious that a single image and then there are altered and compressed, and therefore with little information, we can get a good result. The evidence that I made on the basis of a single photograph does not convince me at all.

This does not detract from that, when we make shots, using the RAW format in the event that we have it, since the photographs leave much sharper because they are not compressed file.

To take a camera with different exhibitions of brightness we need to have this feature. The icon that shows the standard exposure compensation is a “more and less black and white” as seen on the corner of the image on the right. It is also distinguishable because, when the adjust the camera, appears from a rule (usually) -2 to +2, indicating the level of compensation that we make.

As we have to make at least (desirable) three different shots, is quite recommended the use of a tripod. I know a friend who has made the rounds of images without tripod, to support the camera at some or even outgoing pulse, but it is too complicated because, simply by having to touch the camera to change the settings, there may be enough to move that the three photos to be accomplished are not perfectly aligned, and therefore hinders the process and worsens the outcome of the HDR photo.

This would be the manually setting compensation but most modern cameras have this automatic feature called automatic bracketing or fork. In this mode, the camera will automatically switch the exposicióndentro some fixed values to make three shots at the same interval with the continuous shooting after pressing the release button once.

Cameras that carry this option also tend to bring shooting delayed (besides being a very basic and common in all digital), ie slow shooting a certain number of seconds after pressing the button. My personal recommendation is to use a tripod, bracketing and shooting delayed, thus set the camera on a tripod with the site make sure you’re not going to move, delay the start of photographs avoiding the small tremor or movement that can pose pressed the firing button with our finger, and we do that (after a few seconds and either subject), the camera automatically perform all three shots at once. If you do not have braketing, at least, the use of tripod would say that it is virtually obliged, taking great care to manually change the exposure for not moving the camera.

The HDR Image Processing

Well, we already have entries in the HDR. Although you can get all you want (always an odd number, from the image with normal exposure and pairs of images with more and less exposure), it is normal to make three pictures. Here is an example with a photo I made here.

You can see how the camera has three snapshots, with a negative exposure compensation (left), a normal (center) and an offsetting positive (right). As commented, taking these three shots, information processing is now much greater than if simulator with a programme of retouching exposure.

There are different software to try and get HDR images. Among those who know are Adobe Photoshop CS2 (or higher), Qtpfsgui, Photomatix and Artizen. Personally, I have tried all four and I like for its ease of use is the Photomatix. The only thing that is truly free of all these is the Qtpfsgui, but posts to “get” a program (by means having each), the handsome Photomatix, which, in addition, if you want to buy it, is the cheapest of all they (will leave here imagination open to ways of getting each).

Following with Photomatix and not dwell much on this article, in its own page program exists an excellent tutorial on handling this program. Saying that although one study tutorial, the best way to prove it is certainly playing with him. I myself have achieved very different photographs HDR doing twice the generation process, and although at first may seem complicated, barely 20 are the values that define the final result and is better testing and testing.

With three photos above and with Photomatix I could make this photograph HDR (was my first day trying this technique):

How to make good photographs HDR

Keep clicking, the more the better…

But when Will is a good time to do HDR and when not?
The HDR is a technique, as explained in the beginning, adjusting the difference in brightness of a shot to simulate the human eye, therefore, should be used when there are some lighting conditions such that there are sharp contrasts of light and shadows, as it is in essence la que se basa this technique.

Thus, interiors and cloudy days or at sunset / sunrise seem to be good candidates to generate spectacular photographs HDR. It also takes in those areas which appear very dark or very light-saturated in contrast to photography in general. In general, we could say that it is best to use this technique when, to make a shot, we note that the camera pointing to different parts of what we want to get the camera we advised different exposure times. In the example above the monastery, we see that some vaults are lit and others do not, generating a sharp contrast. With the HDR has been able to appreciate the brightness of all of them, without any area that is very dark or very burned. They are also very impressive metal objects because the light that affects them also offers a sharp contrast of brightness.

Finally
I recommend using (in case the camera allows it) a very low ISO. The ISO refers to the sensitivity of the photographic film or image sensor. The higher the ISO, and therefore the sensitivity, the final picture is what is said “more grain,” that is, is less clear, and as we have seen, what matters most in these photographs is the sharpness. If you do not have this option, it is very likely that the ISO default your digital camera, a 100, which is already quite low (I use the photographs for 80 HDR). Already a little grazing photography HDR advanced if we make HDR-moving objects, we have no choice but to do so under one takes (for different shots in the subject will be in different positions), and therefore stick RAW explaining the above. But these cases are already at a level where, when you arrive (and reached), deserves another tutorial with little more level.