The following PDFs contain images of specimens figured in the relevant articles in volume 24. Members who have this volume will be able to match figure numbers.
Sunnyside Deposit, Derbyshire.
The purpose of these images is to convey 3D impressions of the specimens at moderate to high magnification. They have been assembled from images obtained using focus-stacking and have a much greater depth of field than would be available at comparable resolution when viewed through a stereomicroscope. The resolution of several images exceeds that which is possible in a stereomicroscope yet having normal stereo depth.
There are two methods of 3D viewing suitable for a computer screen: red-cyan anaglyphs and side-by-side pairs. Only the former allows the images to be viewed at a reasonable size, but the drawback is that some colours – namely, those that correspond closely to the red and cyan filters in the spectacles – are not faithfully reproduced. It is important that the spectacles used to view the images are red-cyan; there are many red-blue spectacles for sale, but these do not work with red-cyan anaglyphs despite what the advertising may claim. Red-green spectacles will be found to work to a degree, though with a heavy yellowish cast.
The acrylic filters in the spectacles are easily scratched, even by gentle contact with reading glasses, but more robust ones do not appear to be currently available. It is possibly preferable to simply hold them in front of reading glasses, so a type without arms may be chosen. In any case, the length of the arms is not sufficient for some users.
The correct stereo depth is achieved at about 16” (40 cm) distance from the screen. Viewed from farther away the depth perspective is exaggerated; if closer it is flattened. It may be found necessary to increase the brightness of the screen to compensate for the density of the filters in the spectacles.
For detailed observation of the 3D images, it is possible to zoom in on the PDF on screen, but it should be borne in mind that the images have been considerably downsized and compressed in order to be useable on the website.
The files and images remain the copyright of the authors and are provided for personal viewing only. Permission must be obtained for any other use by contacting [email protected] The authors keep full size 3D images in red-cyan anaglyphs, side-by-side pairs and MPO files that are used for 3D full colour projection and 3D televisions.
Comments regarding this new venture are welcome.