How much does the treatment of an image affect the final result?
In this short post I’ll show you “the before and the after”, starting from how the file looks like in .DNG 16 bit format, up to the final output in .PSD (Photoshop) and .PNG format (to be digested by various social networks, as Facebook), a little bit like the various steps followed to extract a trilobite out of its matrix.
In the example, I propose a Scirtidae beetle, commonly known as marsh beetle, since the larvae are associated with environments where stagnant water is present. The specimen comes from the quarry of Yantarny, near Kaliningrad in Russia, known for the rich faunas and flora preserved in amber. Amber, dated to Priabonian-Bartonian (Upper Eocene).
The file was exported from Helicon Focus after stacking 178 frames in 16 bit .ARW format. The frames were acquired at 1/250″, with a Mitutoyo 2.5x objective and a circular LED lighting system developed by OGGLAB. The amber is immersed in glycerin to hide all the deformations that the external surface has, as well as eventual fractures and surface scratches.
The first step is the color correction, balancing of light and dark colors, image rotation (if necessary) and cropping. Below is the image, on the left, as it is saved by the stacking software, and on the right after rotation and cropping.
It is important that the composition of the image follows a kind of golden rule, a balance, an equilibrium, to respect the information that would like to represent. Escape lines, subjects occupying symmetrical spaces, patches of color… everything must be part of a whole as pleasant to the view as possible; obviously this is not always possible, even though ambers lend themselves willingly to this “game”.
On my subjects, I do not only want to illustrate an image that can be interesting from a scientific point of view, but it must also catch your attention, inspire, intrigue, be pleasant [at least I try to…].
After these first essential operations, follows the elimination of the background noise, which is observed in particular in correspondence of homogeneous surfaces. Filtering is done with software created specifically for this purpose (I use DeNoiseAI by Topaz). The noise is much more pronounced the more you work with high ISO values, so it is always recommended to shoot with values as low as possible (100 ISO is the standard).
In the following images, on the left, a sector of the image where you can see the grainy noise present, while on the right the same image where the noise has been removed after filtering.
Another operation is the removal of subjects that can distract, that “dirty” the image, such as internal fractures, bubbles, impurities, bristles… it is obviously important not to remove anything that is part of the insect (or the principal subject) that is photographed. Setae, legs, eyes, the whole organism must be unaltered and only defects (often due in part to the image stacking algorithm) can be removed/corrected. I do not return to the tools available on image processing programs, illustrated in a previous post (HERE).
Finally, a filter to increase the sharpness of the image (if necessary) is applied. Again, in this case I use a software, SharpenAI by Topaz. On the left, the source image, unprocessed, and on the right after color correction, noise removal and application of the sharpening filter.
The final result, after adding the scale bar, the signature and the white frame “to make nice”, is visible below.
Happy stacking!
Extreme macro and Paleontology 