Is there a Smart Underwater LED Strobe in our future?
While underwater strobes have traditionally used xenon flash tubes as the source of light, white light LED COB chips are now available (1). In a recent discussion Pavel Kolpakov suggests that today it is better to build good xenon strobes than to pursue other alternatives (2) . But xenon tubes continue to give us underwater photographers a problem or two, well documented in these pages (3), so let us examine the issue a bit more. (LED: light emitting diode, COB: circuit on board, strobe: underwater flash/strobe and/or TTL strobe, TTL: through the lens metering).
It is true that xenon flash tubes have provided great service since they were developed almost 90 years ago by Harold "Doc" Edgerton of MIT, nicknamed Papa Flash by the crew of the Calypso. But these flash tubes are made of fragile glass, require high voltage and get quite hot in order to activate the xenon's electrons into plasma; plus flash tubes tend to fail or break suddenly as experienced recently by several Wetpixel contributors (3).
Current underwater xenon strobes are difficult to use in TTL mode because the different camera makers use different proprietary TTL codes, which require special expensive TTL adapters; Backscatter has prepared a thorough Guide for these adapters (4), which documents how fragmented and expensive the TTL market is.
To further emphasize the need for change, several models of the popular underwater xenon-tube Sea & Sea strobes, plus the esteemed Inon Z240, have recently been removed from the market for no stated reason and the Sea & Sea YS-D2 has just now been overhauled and re-marketed.
emits 10,000 lumens, and others, foretell the advent of underwater strobes based on these LED's.
Our underwater-LED forecast may include the speed at which solid state LED illumination is being developed, plus the imagination and ingenuity of its aficionados (4c, 5, 6), including Wetpixel contributors since 2011 (6) who continue develop simple circuits (4c, 5) to control an underwater LED flash. Not to mention commercial inventors who patent circuits to ensure that the LED flash emits sufficient light with the correct white balance, does not overheat, and may even provide continuous light to record video (6b).
Smart LED Strobe Functions.
1. Strobe Maintenance Leak detection, battery gauge, flash readiness,function being used, overheating
2. Spot & Focus Lamp Turns lamp off while strobe is fired
3. TTL mode Decodes camera's TTL signal, codes appropriate TTL flashes
5. Video Controls the LED light needed for video
recording and other video illumination functions.
Given the power of today's miniaturized and integrated solid state electronics, the components for these functions should fit comfortably in the LED strobe's water proof case, which might be considerably smaller than current strobe cases.
As further proof of principle, two examples of LED COB camera flashes are a) the simple circuits
The LED Lume Cube is for use on land and gives 1500 lumens of 6000 K light, continuous or strobe.
Though waterproof to a depth of 24 m, it is neither recommended nor usable for UW photography. Yet it
In light of the above, the question is not if, but when, the makers of UW lights will market LED COB based
1a. Cree LED for camera flash: http://www.cree.com/...ents/CPR3ES.pdf
1b. CREE LED COB http://www.mouser.co...JRoCjdoQAvD_BwE
2. Pavel Kolpakov's comments http://wetpixel.com/...ndpost&p=388068
3a. Strobe problem, YSD2 http://wetpixel.com/...showtopic=57102
3b. and http://wetpixel.com/...showtopic=60161
3c. Inon Z240 problem http://wetpixel.com/...showtopic=60074
4a. Table of Flash Triggers http://www.backscatt.../Flash-Triggers
4c. TTL multiplexer: https://www.google.c...=9Py5d83I_65-7M:
5. DIY first LED underwater flash 2011 http://wetpixel.com/...showtopic=40398
6a. LED flash circuits for cell phone camera http://www.electrosc...h-illumination/
6b. LED circuits Hi intensity LED converter https://store.skywor...kyworks/466131/
6c. COB LED lighting, general discussion: http://forum.openag....ed-lighting/966
6d. Power source for LED photo flash, AAT1282 high-efficiency, high-current step-up 2A converter
6e. Flash for camera phones: http://www.cnledw.co...01176530700.pdf
7. Lume Cube https://www.bhphotov...m=Y&sku=1192929