Imaging Basics

Lepidoptera are very well suited for imaging because wing shape and coloration provide much of what is needed for identification. LepNet will produce a total of 255,000 specimen images (see Figure 1 for individual museum contributions). Nineteen institutions will produce 95,170 high-resolution, species-exemplar image suites (male and female, ventral and dorsal) using imaging systems already present at each collection. Members of LepNet have agreed upon 15 imaging standards (Table 1). Collections will load images into the LepNet portal via individual and bulk upload features of Symbiota. We will image exemplar specimens for all species digitized. These whole-body images will be high enough resolution to characterize the morphology of individual scales [55]. Our high-resolution imaging systems can make automontage images of important specimens (type status, historical value, key locality, rare), that are not in perfect condition and require dedicated high-end image systems. These systems will also facilitate detailed images for select taxa that need images of non-wing structures (e.g., tympana, legs, genitalia) to create comprehensive identification guides and publications. The LepNet portal will maintain a master taxon list – noting key metrics of portal images (e.g., institution, locations, sex) – to promote collaborative efforts across institutions. All images will be used for automated taxa identification (LepSnap), geographic documentation for research, and outreach.

Table 1. Imaging Protocol (The 15 standards adopted by LepNet)

1. A dorsal and ventral image of each specimen is required for some Lepidoptera.  See Guide to knowing when to image the ventral surface of Lepidopteran wings

2. The specimen should fill most of the image frame

3. Only a dorsal image is required for smaller micros (e.g., Gelechiidae)

4. Dorsal and ventral views can be separated or combined in a composite image

5. The dorsal view is above the ventral view in composite images.

6. Calibration for size is required in each image (e.g., insert scale bar)

7. Calibration for color is NOT required, having an 18% gray card for white balance correction is required. You may also use a color chart card in each image (e.g., insert X-rite card)

8. Image background should be a neutral gray

9. Use indirect and/or diffused lighting to reduce shadow effects

10. Images should be  6000 pixels on the long dimension.

11. Save a TIF format and create a JPG or PNG version for web.  Images served on SCAN should be above 1400px wide. SCAN will make a medium image: 200px < width <= 1400px    SCAN will make a large image: 1400px < width <= 3200px  Anything larger than 3200 is scaled down to 3200 and saved as a large image.

12. A fully populated database record is required for each specimen image and a unique identifier (e.g., catalog number) should be in the image

13. Images of the labels for a specimen are not required, but can be incorporated

14. Only some specimens should necessitate image stacking (e.g., wing profile other than flat)

15. EXIF metadata includes unique identifier, institution, and other basic data

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