Anaglyphs with Elemental Map OverlaysThis technique is useful for identifying phases causing relief in specimen surfaces. It couples common anaglyph techniques and collection of false color x-ray elemental maps. The example image is of a polished aggregate surface at 100x magnification. The x-ray elemental map was small (256x200) to minimize collection time and was resized to fit the higher resolution secondary electron images used to create the anaglyph.
The example image is at relatively low magnification (100x) and was intended to collect surface features 500 microns and less. The following is based upon this scale; adjustments will be required as magnification is changed. A complete image set is captured at each tilt angle so as to maximize value of the time spent locating features of interest and setting up the instrument.
- Set tilt to zero.
- Adjust scan rotation so that tilting takes place along the image's y-axis. If some rotation takes place as the specimen tilts, make minor adjustments to scan rotation to compensate. Rotation can be checked by noting the location of a feature on the right side of the image (if tilting results in translation to left; left side of he image if tilting translates feature to the right) then tilting the specimen and noting if the feature translated in the y-axis.
- Set to desired magnification and locate a notable feature in the center of the field of view.
- Set the working distance to maximize depth of field. Attempt to get the entire field of view in focus for the secondary electron image. Collect a secondary electron image after optimizing the image.
- Set the working distance to that required by the x-ray detector.
- Center the notable feature again and collect a backscatter electron image after optimizing the image.
- Set beam current to yield desired x-ray count and collect elemental maps.
- After mapping is complete, set tilt to eight degrees and locate the notable feature in the center of the field of view. Doing a good job of aligning the image at this step will maximize dimensions of the final image and reduce the amount of image manipulation.
- Set the working distance to that required by the x-ray detector (same FWD as above). Collect a backscatter electron image after optimizing the image.
- Collect another set of x-ray maps.
- Set working distance to that used for collecting first secondary electron image. Optimize the image and collect a secondary electron image.
Convention has the blue filter over the right eye, this procedure should produce a virtual image having relief in the proper direction. If anaglyph appears inverted (high points instead appear as low points), reverse the cyan/red images.