Revealing Invisible Beauty, Ultra Detailed: The Influence of Low Cost UV Exposure on Natural History Specimens in 2D+ Digitization

Abstract

Digitization of the natural history specimens usually occurs by taking detailed pictures from different sides or producing 3D models. Additionally this is normally limited to imaging the specimen while exposed by light of the visual spectrum. However many specimens can see in or react to other spectra as well. Fluorescence is a well known reaction to the ultraviolet (UV) spectrum by animals, plants, minerals etc. but rarely taken into account while examining natural history specimens. Our tests show that museum specimens still fluoresce when exposed to UV light of 395 nm and 365 nm, even after many years of preservation. When the UV exposure is used in the digitization of specimens using our low cost focus stacking (2D+) setup, the resulting pictures reveal more detail than the conventional 2D+ images. Differences in fluorescence using 395 nm or 365 nm UV lights were noticed, however there isn’t a preferred wavelength as some specimens react more to the first, while others have better results with the latter exposure. Given the increased detail and the low cost of the system, UV exposure should be considered while digitizing natural history museum collections.

Difficulties in Launching Digitization at Museums: The Case of Lithuanian Municipal Museums

“…A new scanning system and crowdsourcing were proposed for industrial-scale digitization (Blagoderov et al 2012). UV exposure for two-dimensional imaging beyond human eyesight was also tested (Brecko et al 2016). Another approach is processing three-dimensional images.…”

Handbook of best practice and standards for 2D+ and 3D imaging of natural history collections

“…For focus stacking photogrammetry in UV, 365 nm LEDs issued from the manicure industry were used (Brecko et al 2016). For multispectral photography and SfM (of medium and large specimens), two LED panels with 16 wavelengths from near UV to near infrared (NIR) were used.…”

“…reptiles (Gruber & Sparks 2015;Martin et al 2013;Prötzel et al 2018), corals (Alieva et al 2008Salih et al 2000), Mammals (Kohler et al, 2019) and many others. UV patterns can be involved in species recognition (Ze-Lin et al 2012;Brecko et al 2016) and sexual selection (Brunton 1998), but are also dependent of environmental factors (Pechacek et al, 2019;Stella et al, 2018). UV fluorescence can also enhance the visualisation of fungus infestation (Fig.…”