In Part 2 said Daniel Mechenbier how to create an HDR image from a series of differently exposed LDR images.
How do I create a HDR image?
It is not magic, to create an HDR image.
There are basically three different ways, To generate HDR images:
1. with a special camera HDR
2. a series differently exposed LDR images
3. as rendering, or. as an artificial computer graphics
In this tutorial I'm going specifically to possible 2 one.
As we have already learned, can be a gägniges LDR image from a digital camera only a very limited dynamic range
Mapping. It is therefore natural, to shoot several images with different shutter speeds, which are then offset against the computer to an image, which the shutter all the images and thus in sum also includes a wider dynamic range than any of the individual.
And just as there will also be made 
To be with my image of part 1 to stay, makes it easy following:
- Camera set up with stand
– Set Full Resolution Sample (So the, what you want to shoot)
– Camera to manual mode switch
– Switch timer, to avoid any camera shake by the trip as much as possible
– three pictures shooting:
Bild 1: Belichtung -2
Bild 2: Belichtung +/- 0
Bild 3: Belichtung +2
I have created my images using a Canon Ixus. It may be, that other cameras, other values for exposure indicate. Basically it means, but, that it made an underexposed image, you must snap a normally exposed image and an overexposed image.
To achieve reasonably useful results on, you should at least 3 Pictures shooting, a so-called exposure bracketing.
To get really good results, should it later, even as 10 be different shutter speeds.
A tripod is indeed essential in order to get exactly the same for each image to extract.
Weiterverarbeitung am Rechner am Beispiel von Adobe Photoshop CS2
Back at the computer, you play the newly captured images to disk, Photoshop opens, der HDR-Bilder ab Version CS2 erstellen kann, und startet über “File” -> “Automate” -> “Merge to HDR” das integrierte HDR-Tool.
There you can first select your pictures, use Photoshop to calculate is. From then on, everything actually happens fully automatically. Depending on the number of pictures it takes a few minutes, Photoshop has signed up the calculation. Finally, a dialog, Set it on the white point of the final image can. If this has happened, Photoshop renders the final image, what you now as a *. hdr, *. tif or *. exr file can save.
Other formats are not possible at this stage, because the image is still a color depth of 32bit per channel. Um ein JPG-Bild zu speichern muss daher vorher noch die Farbtiefe über “Image” -> “Mode” -> “8Bits/Channel” auf 8bit pro Kanal runtergeschraubt werden.
 |
 |
 |
| Bild 1: Unterbelichtet Outdoor area is clearly visible, for "Drinks" from the inside, he too dark. Details are as good as not recognizable. |
Bild 2: Normal belichtet Outdoor area irradiated, for internal all details, For example, the plant, recognizable. |
Bild 3: Überbelichtet The exterior is so strong over-exposed, that the window almost completely "burned off" and not is more evident. |
Bild 4: Fertiges HDR-Bild
That's better. Within- and outdoor use are considerably
identified and would, when used as a Reflection Map,
quite realistic reflections provide.
My example above, a single image is, established, ca. 10 Has lasted for minutes. Als Reflection-Map in 3ds Max, Maya, Softimage software or what ever, however it is not really need to, as one works best for this purpose with a 360-degree panoramas, can enclose the entire scene.
Their creation, of course, takes longer. A normal 360-degree panorama consists of a rule 10-15 Pictures. So this value you must times 3 expected, or. times the number of shutter speed, The internalisation want it, because it must be so fired for each exposure level a separate panorama. And depending on where it must of course go fast. If you Taken outdoors you have to consider, that the lighting situation is constantly changing. Half an hour snap pictures can even result in a change in the sun or a different cloud.
Alternatives to Photoshop?
Since the theme of HDR has become in recent years more and more important and interesting, is also increasingly relevant software, to generate HDR images and process. Other applications would be FDR Tools Advanced and Photomatix Pro. The last two are special HDRI tools, and therefore significantly less expensive than Photoshop. Those who still would like to work with Adobe Software, should perhaps look at Photoshop Elements. Even he can genri HDR images, but offers fewer editing options.
When you create complete 360-degree panoramas would like, must occur before the HDRI creation of course yet another step. Namely, the assembly of the various panoramas with different shutter speeds. Only after this is done, Photoshop, you can specify these panoramas as a source for the HDR image.
Program, can create panoramas from individual images, for example, are Autodesk Stitcher, Photoshop also
CS2 oder PhotoStitch von Canon. A list of other programs can be found here:
http://www.fotocommunity.de/info/Panoramasoftware
Many thanks to Daniel Mechenbier for this tutorial!
Loading ...
