HDR stands for High Dynamic Range. Dynamic range relates to the capacity of cameras or software to display both bright and dark image segments.
You can find more information on HDR images here.
Before acquiring an HDR image, the necessary exposure range needs to be determined for the current sample. The exposure range is made up of a minimum and maximum exposure time as well as several exposure times between them. A recently determined exposure range will continue to be used for all HDR images until you let your software determine the exposure range anew. It is irrelevant whether the exposure range had been determined automatically or manually.
If you are acquiring several images of the same or similar parts of a sample, you don't need to determine the exposure range each time. If you change the sample or adjust settings on the microscope, it is recommended to determine the exposure range anew (either automatically or manually).
Acquiring an HDR image with an automatically set exposure range
Acquiring an HDR image with a manually determined exposure range
Acquiring more HDR images without setting the exposure range anew
Acquiring an HDR image with an automatically set exposure range
With this procedure, your software automatically determines the exposure range. To do so, your camera automatically acquires a set of images with various exposure times and measures the amount of over and underexposed pixels. The exposure time continues to change until the amount of over and underexposed pixels is within defined limits. At this point, the exposure range has been defined. How much the exposure time is adjusted by is determined by your software with regards to the minimum and maximum exposure time.
Preparations
1.Switch to the Acquisition layout. To do this, use, e.g., the View > Layout > Acquisition command.
2.Switch to the live mode, and select the optimal settings for your acquisition, in the Camera Control tool window.
•The automatic exposure time detection uses this value as a basis and raises the exposure time so as to correctly light even the dark parts of the sample.
3.Search for the part of the sample which you want to acquire an HDR image of. This should be a position which has such significant differences in brightness that not all segments can be shown with optimal lighting.
4.Finish the live mode.
Acquiring an HDR image
5.In the Camera Control tool window, select the Activate HDR check box.
6.In the upper part of the tool window, the Snap 
button changes to the HDR 
button.
6.In the Determine exposure range group, click the Automatic button to have the exposure range determined automatically.
7.The necessary exposure range will now be determined. To do so, the camera automatically acquires several images which only differ in exposure time. This acquisition occurs in the background, which means that the images are not shown in the document group. The exposure range determined in this way will continue to be used for all HDR images until you let your software determine the exposure range anew.
8.Determining the exposure range automatically takes about 30 seconds. Pay attention to the progress bar located in the status bar. When all elements in the tool window are active again, the process has finished. In the Total time field, you can now see how long is needed for the HDR image acquisition.
9.If, in the Acquisition Settings > Acquisition > HDR dialog box, the Automatic HDR preview check box is selected, the HDR image will be acquired and shown automatically, once the exposure range has been set.
7.If the HDR image has not been acquired automatically, click the HDR button, in the Camera Control tool window, to start the image acquisition.
•The image acquisition will begin. Pay attention to the progress bar located in the status bar 
. It shows how long the acquisition has taken so far and the total acquisition time. The progress bar contains the Cancel button, which you can use to stop the current image acquisition.
•After the acquisition has been completed the HDR image will be shown in the document group.
8.Check the image. If you want to change the settings (to use a different algorithm for the output rendering, for example), open the Acquisition Settings dialog box. Select the Acquisition > HDR option in the tree view.
9.You can find more information on this topic here.
9.If you don't want to change any settings, use the File > Save As... command to save the image. Use the recommended TIF or VSI file format.
10.These are the only formats which also save all the image information including the HDR entries together with the image. This means that you can always see whether or not an image was acquired using HDR. Open the Properties tool window, and look at the data in the Camera group.
Acquiring an HDR image with a manually determined exposure range
With this procedure, you set the minimum and maximum exposure time in the Camera Control tool window yourself. Your software guides you through the process with relevant message boxes. How much the exposure time is adjusted by is determined by your software with regards to the minimum and maximum exposure time.
Preparations
1.Switch to the Acquisition layout. To do this, use, e.g., the View > Layout > Acquisition command.
2.Switch to the live mode, and select the optimal settings for your acquisition, in the Camera Control tool window. Choose an approximate exposure time.
3.Search for the part of the sample which you want to acquire an HDR image of. This should be a position which has such significant differences in brightness that not all segments can be shown with optimal lighting.
4.Finish the live mode.
Acquiring an HDR image
5.In the Camera Control tool window, select the Activate HDR check box.
6.In the upper part of the tool window, the Snap button changes to the HDR button.
6.In the Determine exposure range group, click the Manual... button to define the exposure range for this acquisition anew.
•The Determine exposure range message box appears. It prompts you to reduce the exposure time so far that enough image details can be recognized in the bright image segments and no segments are overexposed.
7.Change the exposure time in the Exposure group, which is part of the Camera Control tool window. Make sure that the Manual option is chosen. You can change the value by using the slide control or by entering an exposure time with the keyboard and pressing the [Enter] key. Check the live image on display. Once the bright image segments are no longer overexposed, click the OK button in the Determine exposure range message box.
•By doing so, you have determined the lower limit of the exposure range (=the shortest exposure time).
8.Now, the Determine exposure range message box prompts you to raise the exposure time so high that the dark image segments are no longer underexposed. Change the exposure time in the Exposure group, which is part of the Camera Control tool window. Check the live image on display. Once the dark image segments are bright enough, click the OK button in the Determine exposure range message box.
•By doing so, you have determined the upper limit of the exposure range (=the longest exposure time).
9.Click the HDR button in the Camera Control tool window to start the image acquisition.
•The image acquisition will begin. Pay attention to the progress bar located in the status bar . It shows how long the acquisition has taken so far and the total acquisition time. The progress bar contains the Cancel button, which you can use to stop the current image acquisition.
•After the acquisition has been completed the HDR image will be shown in the document group.
10.Check the image. If you want to change the settings (to use a different algorithm for the output rendering, for example), open the Acquisition Settings dialog box. Select the Acquisition > HDR option in the tree view.
•You can find more information on this topic here.
11.If you don't want to change any settings, use the File > Save As... command to save the image. Use the recommended TIF or VSI file format.
•These are the only formats which also save all the image information including the HDR entries together with the image. In this way, you can see, e.g., whether or not an image was acquired using HDR. Open the Properties tool window, and look at the data in the Camera group.
Acquiring more HDR images without setting the exposure range anew
If you have just acquired HDR images of the same or a similar sample, as a rule, it is not necessary to determine the dynamic range anew. In this case, you have already completed the preparations for acquisition and set the HDR image acquisition settings correctly (such as choosing the optimal algorithm used for output rendering) anyway.
In such circumstances, acquiring an HDR image is especially easy. Do the following:
1.In the Camera Control tool window, select the Activate HDR check box.
2.Click the HDR button in the Camera Control tool window to start the image acquisition.
3.The image acquisition will begin. After the acquisition has been completed the HDR image will be shown in the document group.
3.Check the image before saving it.
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