Testing budget photosystems to reach an optimal solution for the herbarium digitization purposes

The current paper stresses the application of different budget photosystems for digitization of herbarium specimens. Twelve photosystems were compared by color accuracy reproduction of the images. It was found that the photosystem built on the basis of photocamera Canon EOS 800D and fixed lens Tokina AT-X M35 PRO DX AF 35 mm f/2.8 Macro and currently used for the digitization of the LWS herbarium collection demonstrated the best results among other tested photosystems. It also produced the images with the same or even better color accuracy as in images downloaded from P, PI, B, and W virtual herbaria. Nevertheless, its color accuracy measured as ΔE2000, in general, does not meet recent criteria ascertained for the herbarium digitization purposes and new FADGI’s requirements. This photosystem has been found to have improving potential and, hence, should be optimized. On the other hand, it was also shown that smartphone Samsung Galaxy S10 could produce images with the same or even better color accuracy compared to some images deposited at P, PI, W, and B virtual herbaria. Therefore, in conditions of extreme situations and hostilities, such smartphones with additional external illumination can serve for urgent digitization of natural history collections. Finally, we doubt the application of commonly used color targets for the digitization of herbariaum preserved specimens since the original living color of such specimens is usually lost during conservation and preservation. Instead, it would be more beneficial to apply advanced targets to evaluate the spatial accuracy of images since they can incorrectly represent the important morphological characters of preserved specimens.