Angry Blue by definition starts at 5,793.34 Kelvin and continues until Murder Blue which starts at 5,793.35 Kelvin.
Most people murdered while using a light are above the Angry Blue number, and most people beaten are between the Angry Blue and Murder Blue ranges.
(This is according tho the latest FBI statistics.)
Just a comment:
I also tried the Ultrafire DV-S9 when it was on sale in Gearbest quite some time ago. A friend also wanted to get one but it wasn’t on stock in Gearbest anymore so I ordered one for him from ultrafire.com too.
What I noticed: the LED of the earlier DV-S9 from GB looks like an XM-L2 (I can’t verify if it’s genuine or not, but it looks similar to the genuine XM-L2 on the Convoy S2+). But the LED from ultrafire.com DV-S9 doesn’t look like a genuine XM-L2. (genuine XM-L2, dots are in alternate pattern; the “non-genuine” XM-L2 LED is in straight pattern).
Regarding lower brightness — I’ve noticed that when the magnetic slider is on the max position, it still doesn’t reach highest brightness (if I use my “shine light thru portable fan” method, there will be some PWM noticeable). However, if I place a magnet on the top of the slider’s max position, then the DV-S9 light will become noticeably brighter - and using the “shine light thru small portable fan” method, there is No PWM when on max output — meaning it has reached its max brightness).
The same (place magnet on DV-S9 slider) is actually true for the DV-S9 from GB and DV-S9 from ultrafire.com. The GB DV-S9 seems to be just slightly brighter on max than the ultrafire.com DV-S9 on max (probably due to use of the XM-L2 clone LED)…
An advantage is that with lower brightness (magnetic slider not really reaching max brightness), is it draws less current, and consequently will have longer runtime.
That’s something new to me (“cooler wave lengths penetrate better in water”).
I’m curious then: Sofirn’s SD02A diving flashlight uses a warm 3000K tint (I notice most other budget flashlights labeled as “diving” light often just use the default cool-white, with some seem to be closer to “angry blue”) — so is there any advantage for warm tint on water? or it’s not really a good choice done by Sofirn?
Depends on the dive location, and the diver visual goal. The red spectrum disappears first underwater. That’s why water is blue, It’s the only color that comes ‘back out’.
If the water is clear, and it’s important for you to SEE the reds, then a warm light may be the ticket. At 100 feet pretty much everything looks pretty gray without light.
OTOH, if you are in cold green water, with poor visibility (like I am), then penetration and signalling might be a more important consideration. The underwater landscape is not as pretty anyway so fussing about minor color shift is not such a big deal.
Photography, either still or video, adds additional complexity to this decision.
Huh… interesting! Never even though to test “external turbo” with another magnet. :laughing:
Didn’t even compare the ones I got to compare LEDs.
I must be very complacent.