You’d carry an umbrella if it was going to rain, right? Being prepared is good. it gets dark every single day. And you often need more light in underlit places. I always carry a flashlight around with me for this reason.
My flashlight of choice is the Emisar D4v2, with SST-20 4000K LEDs.
I fricking love this thing. It’s great for darkness, vibe(it creates an amazingly moody atmospheric lighting when it’s on candle mode and pointed at the ceiling.)
What Batteries does it use? The D4V2 uses 18650 batteries. 18650 is the size descriptor for lithium-ion batteries, 18mm diameter/65mm length. it has high current requirements, so you need IMR batteries for high current applications, around 10-15A discharge rate. I like the LG HG2
What do all the numbers mean? The D4v2 is an enthusiasts flashlight(for a glimpse into what that means, take a look at the UI below - all that happens with a single button)
The D4 is the name of the flashlight, v2 signifying it’s the second version of the flashlight. The v2 brought with it several improvements, like an always on set of aux LEDs in RGB colours(I use these to indicate the current battery level)
SST20 - LED brand The SST20 is the brand of LEDs that are the main emitters in the light(it has 4 of these).
4000K is the colour temperature of the light that it emits. The colour temperature is basically the “warmth” or tint of the light that is emitted. A tubelight would be 4500-6500K, while a candle or incandescent light would be 2500-3000k.
Before this, I had the D4v1, in the Nichia 219CT 90CRI, 5000K configuration. It was “cooler” than the current 4000K D4v2 I carry. To be honest, I would now want something even warmer to carry, and will probably go to 3000K next time.
Why do I like this light? Simply, it’s a powerful, versatile light with many different modes in a carry able package. It has an insanely low “moonlight” mode, for use at night without waking up sleeping people, and gets so bright it can simulate daylight at night. It has a number of different modes for various fun situations, and the brightness is adjustable with infinite steps. The battery life is also good, it uses an easily available rechargeable, replaceable power source, and it has a number of QoL features rarely seen in regular flashlights. I also really like the UI.
How do you access all these different modes? What is the UI like? D4v2 runs a special open-source firmware designed for enthusiast flashlights. It is developed by the venerable Toykeeper, specifically to allow for modding and a variety of features with limited control surfaces. There is a single clicky button on the D4, which can be used to access every single mode on the flashlight with a combination of clicks and holds as described below.
Some of my favourites are
- Candle - This mode creates a gentle flicker on whatever setting it’s at. This is great for dark rooms with inadequate lighting(I hate white lighting), or tents. It creates a gentle wash of light with a slow flickering that can be super romantic, vibey, or moody depending on the brightness. Highly recommend.
- Party Strobe - This is basically a portable strobe machine. You can adjust the frequency of strobe to whatever you want, allowing for use as an art tool as well. Point it at the fan, speed it up and slow it down, reversing the motion at will. Point it at the ceiling, and you can get people dancing with no trace of self consciousness, because everything looks cool.
- slow strobe looks stop motiony and animated
- fast strobes look operalike, or as if they’re 60fps
- Lightning - This one creates a lifelike lightning effect, with slow pulses of light with occasional bursts of full brightness. You really have to see how bright it is to believe it. In any of these modes, you can adjust the frequency or brightness by holding down the button to increase, and decrease by holding down the button, releasing it, and holding it down again.
To get to these modes, double click and then hold from off.(that’s click-click-hold). This puts you in the strobes section of the UI. From there, 2 clicks(click-click), gets you to the next modes, in order, candle-lightning-beacon-party strobe-tactical strobe)
What QoL features are you talking about? Some I really like are
- Magnet in the tailcap - The magnet helps a lot in situations. Can clip it to any metal surface and it will hold easily. Damn convenient.
- Aux LEDs - apart from the main emitters, there are 8 small leds around the outer ring of the light. These serve to indicate the current battery level, or to locate the light in the dark(that’s right, the flashlight has lights so you can find it to make more light)
- Accessible Software - the brains of the flashlight have exposed headers, so you can connect the PCB to your computer if you have the right tools, and update or upgrade the software as you wish.