thetrickster 328 Posted January 5, 2014 Looking at options to video lights... I was all set on the Keldan 4Vs but got told the CRI rating is poor (70) - so with this info I've started looking at alternatives (for around the same money €1000 per lamp) and similar size for travel. I came across the Aditech Mangrove set there: http://www.aditech-uw.com/en/shop/1892-mangrove-videosystem-vs-12l12.html Pretty impressive output !! (if its true) and a higher CRI rating - if this at all makes much difference? Anyone got any comments on these / mangrove's ? Thanks Share this post Link to post Share on other sites
jonny shaw 16 Posted January 5, 2014 Also have a look at HDV seatek, the guy that builds the lights George is a good guy and I have purchased 2 x 10,000 lumen LEDS from him, they are well made, a reasonable size but nothing silly and have high CRI and lovely colour and fall off, Oh and they are competitively priced. Share this post Link to post Share on other sites
ChrigelKarrer 52 Posted January 5, 2014 (edited) I use 2 Mangrove MVS-4L6 video lamps. They are nicly made, no frills, no design awards, but they are working well.4320 Lumes as mine is rather useless under daylight conditions and more far than 3 feet but they have a nice, wide spread. I had a flood on one lamp head because the lamp switched on out of the water and melted the o-ring leading to a subsequent flood, a 100% user error. Mangrove repairde it for a reasonable price in a few days after shipping it to them in Spain. Contact Ryan from Reef Photo and Video in Ft. Lauderdale as he is a seller for Mangrove, he may give you one to test. Chris P.S. I just realized that you are in Gibraltar, contact Mangrove in Spain, they are well informed and helpful. Edited January 5, 2014 by ChrigelKarrer Share this post Link to post Share on other sites
thetrickster 328 Posted January 6, 2014 (edited) Thanks. I think I'm going to discount these, as from the specs the Kelvin rating is wide (3000k-6000k), even though on the tech spec page it states 5000k - so I'm unsure where they get their CRI rating number from. Just called Aditech - website is wrong. They are indeed 5000k.. Edited January 6, 2014 by thetrickster Share this post Link to post Share on other sites
Graggs 3 Posted January 6, 2014 (edited) I can't comment on the individual products above or their suitability, but for the benefit of people reading this, here is a quick explanation of CRI / Colour Temperature and other interesting LED light output stuff. The CRI shouldn't be confused with the colour temperature (expressed in °K .... degrees Kelvin)CRI stands for Colour Rendering Index and is an expression to determine how faithful colours 'look' under a given light source. °K .... degrees Kelvin is an expression of colour temperature, the lower the figure, the nearer to the warm end of the spectrum (fire / candle) the higher the figure, the nearer to the Blue end of the spectrum. Daylight being about 5,000°K ~ 6,500°K As an illustration, a Tungsten Halogen light source of around 3,000°K can have a CRI >95 and by comparison a fluorescent light source with a colour temperature of 5,000°K might have a CRI of <75. Part of this is due to the spectrum of light that the light source is emitting. The 'Spectrum' being all the various colours (think rainbow or prism), In the image below, you can see the Halogen lamp (middle) emits a continuous range of colours whereas the fluorescent (bottom) has whole sections missing (or too dim to be any use). LED's have much the same problem as the fluorescent above, they not only have major deficiencies in certain colours (technically wavelength) BUT also have 'spikes' in some colours - the right hand image below shows our Tungsten light source. LED's are notoriously bad in the CRI department. But they are getting better. You also have to treat the manufacturers CRI readings with caution, as they can be fudged. A result of this can be seen below, the image on the left is lit with Tungsten and the right with White Phosphor LED source. Look at the skin tone of the right hand image, the lack of correctly coloured light (or light deficient in certain wavelengths) has rendered the skin wrong. In contrast the blue spike in the LED light source on the right has made the dress look too blue (in fact it's changed the colour of the dress altogether). And this is before you shine the light through water with particles in it or take into account the degradation of the LED over time. Another consideration... but way outside the scope of this thread is the sensors ability to record this information, i.e how sensitive it is to various colours or wavelengths. It's all relative of course and most dive sites are NOT offering perfect filming opportunities. But I felt the above distinction might help? A couple of the above images come from this old thread, which is worth a read if you want to expand on the above. It is old but still relevant to some of the points above. http://www.cinematography.com/index.php?showtopic=52551 Edited January 6, 2014 by Graggs 3 Share this post Link to post Share on other sites