Here are three examples of time lapse videos captured in the absence of visible light. Two videos were captured under ultraviolet-A (UVA) illumination and one under infra-red (IR) illumination.
Infrared (940 nm)
The night of a plant, 11 h 20 min condensed into a 10 s-long video. Only source illumination were two LEDs emitting infrared radiation at 940 nm (LED Engin LZ1-10R702). Camera: Olympus E-M1, converted to full spectrum, adapted Soligor 35 mm f:3.5 objective at f:8, Heliopan RG780 long pass filter on lens. Movement is most evident with the video at full screen resolution. Images converted to greyscale.
Ultraviolet-A (385 nm)
The night of a plant, 9 h condensed into a 8 s-long video. Only source illumination were two LEDs emitting ultraviolet-A radiation at 385 nm (LED Engin LZ1-10UA00). Camera: Olympus E-M1, converted to full spectrum, adapted Soligor 35 mm f:3.5 objective at f:8, StraightedgeU bandpass pass filter (UVROptics) on lens. Movement is most evident with the video at full screen resolution. False color, white balance set on white PTFE target.
Ultraviolet-A (365 nm)
The night of a plant, 12 h condensed into a 11 s-long video. Only source illumination were two LEDs emitting ultraviolet-A radiation at 365 nm (LED Engin LZ1-10U00), except during the last 90 min with skylight entered through a nearby window. Camera: Olympus E-M1, converted to full spectrum, adapted Soligor 35 mm f:3.5 objective at f:8, Baader U bandpass pass filter on lens. Movement is most evident with the video at full screen resolution. False color, white balance set on white PTFE target.
Plant at the end of third session. Window light, Firecrest UVIR filter.
IR images edited in Capture One, UV images edited in PhotoNinja, videos created in ImageJ (Fiji distribution).
I will describe the rig I used in a separate post. The photograph below gives a preview.
Camera “rig” as used for the three videos. Only the LEDs and filter were swapped between sessions and the objective re-focused at the start of each session. Photographs were taken on three consecutive nights, and the plant returned to a well lighted place during each daytime.
All illustrations, videos and text are of my own authorship, and copyrighted.
(c) 2017 Pedro J. Aphalo