Images of Modern Sri Lanka bank Notes when illuminated by Ultra Violet Light

Part of notes.lakdiva.org.lk a website for
Banknotes of Ceylon and Sri Lanka since 1785.

Most Beautiful Sri Lankan Currency notes under Ultra Violet Illumination.

S. W. R. D. Bandaranaike Portrait
Series 4: 1971-1974 notes

King Parakramabahu
Series 5: 1974-1977 notes

Armorial Ensign of Sri Lanka
Series 6: 1977 notes

Flora and Fauna
Series 7: 1979 notes

Historical and Archaeological
Series 8: 1981-1985 notes

Historical and Development
Series 9: 1987-1990 notes

Sri Lanka Heritage
Series 10: 1991-2006 notes

Development, Prosperity and Sri Lankan Dancers
Series 11: 2010-2019 notes

The Visual notes were scanned at 300 dpi and displayed at 50 dpi.
UV images also photographed at about 300 dpi with a Cannon Power Shot SX620 HS Full HD 20.2 Mega Pixel using 3 MB (2048x1536).
Remember to switch off the Date option so that it does not overlay the digital image of the note.

Camera mounted on a tripod and a UV lightbox fixed with two 8W 365nm wavelength 288mm long Fluorescent tubes.
I find the 365nm gives better images than 395nm which is also sold as UV light. Shorter wavelengths should not be used as they are not safe for eyes and skin. Older cameras may not be sensitive to UV wavelengths and may not give good UV images.

To get uniform illumination for photography you need UV-tubes. The rechargeable UV torch is more convenient to carry with you and use when needed. UV-light is an essential part of a banknote collectors tool kit and are inexpensive in most major online stores. I have 50-year-old Unc notes that still show clear UV printing, so I infer UV does not degrade with time, if stored properly. Could have got partly rubbed away in a well used worn note. I am told UV is checked by PMG when notes are graded.

Unlike a scan a digital photograph will always be slightly trapezoidal showing the perspective effect, as the distance to the four corners of the images from center of camera lens are different. So using for example, PhotoShop Elements software application,

• First crop the image to minimize the background showing.
• Straighten image using option. Selecte -> All + Image -> Transform -> Skew. Start with the largest and work down to skew each corner by draging each corner of the trapezoid, horizontal and/or vertical to move corner of note images to corner of digital image and get a rectangle.
• Change the image size using option Image -> Resize -> Image Size to the actual size of currency note and required resolution. The camera images were close to 300 dpi and were resampled using Bicubic spline to 300 dpi any slight change of aspect ratio and pixel resolution.
• I also found it useful to Enhance -> Brightness(+30)/Contrast(+10) the dark images to brighten the image and highlight the UV printing.