Edit Shading Images

Using shading correction, your software can remove image structures that originate in the imaging system and don't belong to the actual image information. The shading correction requires correction images. Correction images are required for every camera resolution and for every high voltage of your transmission electron microscope.

Use the Edit Shading Images dialog box to check which shading correction images are available and, if necessary, which need to be newly acquired.

Opening the dialog box

Description of dialog box

List of all shading correction images

In the dialog box, all valid correction images are listed. The list contains the following information about the correction images.

Shading type	The detection of shading artifacts requires the acquisition of two types of correction images: dark current correction images and flatfield correction images You can find more information on these correction images here.
High voltage	The flatfield correction images depend on the transmission electron microscope's acceleration voltage.
Magnification range	In a transmission electron microscope, the imaging conditions change significantly in different magnification ranges. You may require different correction images for the different magnification ranges.
Resolution	Correction images have to be acquired for every possible camera resolution.
Date	The acquisition date is shown
Exposure time	The exposure time for the flatfield correction images depends on the binning factor and is computed automatically.
Camera Mode	The camera mode is only displayed with the Morada G2 and Quemesa cameras.

Viewing shading correction images

Select one of the shading correction images in the list. Then click the View button to load this correction image into your software's document group.

Deleting shading correction images

All shading correction images are automatically saved as files after acquisition. Select one of the shading correction images in the list. Then click the Delete button to delete this correction image. By doing this you are not just removing the entry in the Edit Shading Images dialog box. You're physically deleting the file from the data storage medium.

Shading correction images are automatically deleted when you change the magnification range. You will be asked to acquire new flatfield correction images for the changed magnification range. Dark current correction images are kept.

Defining the magnification range

In a transmission electron microscope, the imaging conditions change significantly in different magnification ranges. For example, lenses are switched off to realize a lower magnification.

In this case, define several magnification ranges. Which ones, exactly, you need and how many of them you need, depends on your microscope. For example, define three magnification ranges with low, medium and high magnifications. Acquire your own correction images for the flatfield correction for each magnification range.

Click the Edit Magnification Ranges... button to define new magnification ranges. You will find a step-by-step instruction for doing this here.

Acquiring new correction images for the shading correction

Click the Calibrate... button to acquire new correction images. The correction images replace all existing correction images for the current microscope magnification and acceleration voltage. Images with a different acceleration voltage are kept, however, and will be used again if required.

Switching shading correction on or off

Note: Shading correction is a necessary procedure in order to ensure that you can acquire high quality images with your camera. For this reason, intentionally only turn shading correction off temporarily.

Select the Flatfield entry in the list to activate the flatfield correction. With the flatfield correction, you will automatically also activate the dark current correction.

It is also possible to switch on the dark current correction only. To do so, select the Dark current entry.