Sep 30, 2020

Convoy S21B and S2+

I ordered these lights at the beginning of the month but they took forever to arrive.

The package came from China but actually landed in the US within 4 days. However, at that point, the carrier messed up and routed it to Utah, Nevada, back to CA, then bounce around in CA for a few days before arriving at my door. Sigh...
Anyway, what matters is they're finally here.

I originally wanted a Convoy S2+ with the high powered SST40 emitter (1800 lumens vs 1000 on a typical S2+) so I can add my brass 18350 battery tube to it. However, when it arrived, I found that the thread on the new S2+'s are different now so the brass tube doesn't fit. Doh!

I also wanted a 21700 version so I ordered the S21A (2300 lumens). However, just after I ordered, I learned about a new Convoy flashlight called the S21B. I contacted Simon (manufacturer of all Convoy lights) to switch to the new light. He did it and threw in 2 lighted tail cap switches to boot. 😍

Lowest emitter modes

I love the S21B but the S2+ (at 1800 lumens) is no slouch. Both are very bright.

Brightness comparison
Camera fixed to F1. 5, 1/60s, ISO 400, 5000k WB
*Note: the S2+ high and max mode are dimmer  because I was using a low battery (my bad). 
With fully charged battery, its high and max modes are close to the S21B's.

Beam on max brightness (camera auto-compensated)
Left is S21B vs S2+ on right
This is with 2x 5500 lumen LED shop lights in the background so the beams are much brighter than this picture.

On max, the head on both lights warm up within 40 seconds.
The S21B's black aluminum body feels like it's rubber coated but it's just matte anodized aluminum. Very different design from S2+. The stainless steel bezel is a nice touch although I wish it was a bit larger to create more of a contrast against the rest of the body.

Beautiful emitters & AR glass

Said emitters in lowest mode

Pretty close in size. S21B on top accepts 21700 battery (also 18650) while the S2+ takes 18650. 
That gap between tail cap and battery tube bothers me a bit, but that's my OCD talking 😂

Both are SST40 5000K so they look very similar. This emitter is a bit green on lower power but they're bright white on high or max.

The 2 new lights flanking my current favorite Convoy light: Sand S2+ with 18350 brass tube.

I modded the S2+' s tail switch to a blue lighted switch then changed it to orange. This is on 20% remaining battery so it's dim. 

Here's a pic of it on fresh battery vs S21B (which will get the blue button treatment soon)

ZEROSVN Tech Enthusiast

Sep 26, 2020

Keep them poor!

Wow. This short speech is eye opening.

We all know we have to work but we've been doing it wrong. You're not supposed to receive a paycheck.

Here's another great video. It talks about many things but the one that stood out to me is the 3 types of income. 

ZEROSVN Tech Enthusiast

Sep 20, 2020

New flashlight: Lumintop FW3A

This baby arrived in the mail yesterday. I couldn't help but take it out for a spin.

I don't have any shot of the original light as I immediately converted it to short form with the 18350 copper tube that arrived last week.

This is a 2800 lumens, tri-led flashlight from Lumintop. It is designed by the folks at As such, it runs the open-source Anduril user interface.


Emitters: 3 x LEDS on Copper DTP MCPCB 
     Cree XP-L HI 3D (Neutral White 5000K)
Optic: TIR Carclo 10511
Lens: Glass with AR coating
Max Output: 2,800 lumens

In 18650 (original, long) form, it runs at max brightness for about 2 minutes before getting too hot. In 18350 form, it runs about 30 seconds before getting warm. After a minute (and multiple turbo runs), it's uncomfortable to hold due to the copper tube's high heat conductivity. This is a true "pocket rocket" after all.

FW3A in sand & copper
2800lumens, 5000k goodness in a super short body (18350)
This is shot in my "studio", aka the top of my convection oven, against the kitchen backsplash 😁


Typically $50 but it can be had for ~$38 on sale. I bought mine from Lights and Tools, a small specialized tools dealer in Mississippi.
+ $10 for 18350 copper tube
+ $10 for Turboglow GITD gasket

Cigar-grip dual-wielding

Lumen candies
That optic looks fuzzy because it's frosted to create a diffused, smooth beam.

Lowest possible beams
Color Temps (left to right): XPL-HI 5000K, XPL-HI 6500k, SST20 4000K

Comparing green Turboglow (glow in the dark) vs Aux green led on D4SV2

Low beams on with 18650 battery for size comparison

The FW3A looks like a salt shaker

Cigar grip

Love that beautiful Turbo glow
It's bright, even in a well-lit room

Brothers in sand
The sand color on FW3A is darker than the desert sand color on the S2+. I like the lighter tan color but the chocolate brown on FW3A fits well with copper.

The D4SV2 in 26350 form is down right stubby. I like it in the regular 26650 form better...maybe because of the knurling.

For everyday carry, I needed a clip. The included clip is too long so I had to find another solution. Here's the clip from S2+. It's not the best but it will do for now. 

Some final thoughts:

  • This flashlight is a lot smaller than I expected. I got the Emisar D4SV2, which is a big brother to the D4V2 (direct competitor of this light) and it was fairly large. The D4V2 is also pretty nice and, seeing pictures online for both "edc" lights, I expected the FW3A to be a bit bigger than it is. Pleasantly surprised when I saw it in person. It's a good surprise though as it's definitely pocketable.
  • The electronic button takes some getting used to. Initially I had a few clicks that didn't register. You have to get used to pushing in the middle of the button. That said, the shallow stainless steel button is a beauty.
  • Very bright for its small size. I'm using vapcell 1100mAh battery for the short body but I'll probably use it more with Sanyo GA 3500mAh battery in long (18650) body.
  • I wish it had a drilled lanyard hole in the back. It would be quite painful to drop this beauty. Ugh...can't even think about that. They do sell a small lanyard ring thing but it sticks out and wouldn't feel right in pocket so I skipped it.

ZEROSVN Tech Enthusiast

Sep 19, 2020

Poets of the Fall - Where Do We Draw the Line

Such a sad but beautiful song.

It's fair to say that things haven't been easy in 2020. In this time where many of us are going through sadness, loss, pain, uncertainty, or depression, we need comfort, and a reminder that we still have our freedom: our choice.
ZEROSVN Tech Enthusiast

Sep 8, 2020

Poets of The Fall - Angel

This is such a beautiful song, both acoustically and and poetically.

Poetry in Rhyme. Vocals in Flight. Music for the Soul.

This tear I cry...falls like healing rain. Softly soothe my pain...

My home is my skin
And in the world I've within
All I have... Is my love for you...

If I can seal my fears. Will I be in the clear?
Or am I giving phantom pain

Cos it's playing out... Every note in the score.
I surrender once more...

ZEROSVN Tech Enthusiast

Sep 7, 2020

A dive light you can use around the house: Wurkkos WK20s

In my quest to try different kinds of flashlights, I came across dive lights.
These are flashlights that are extremely waterproof and can shine further than typical flashlights.

I don't dive but I go swimming quite often. I figured I might need a dive light one of these days. Until then, a light I can carry around and not have to worry about getting water damaged could be useful. I saw a deal on the Wurkkos WK20s and figured I'd check it out. One of the main reasons I wanted it is the advertised 2000 lumens at a sustained 1.5hrs! That's a long run time for that much light.

I wasn't planning on doing a review right away but, since I had time during Labor Day weekend and it arrived ahead of schedule, I might as well put up a review.

This is a decent light to have around the house. Its 2000 max lumens plus 4 brightness modes are more than most people need. There's a similar model called WK20 but I opted for this one as it has twice as much lumens and is about the same price.
Being a dive light, the WK20s is guaranteed to be waterproof down to about 500ft (150 meters). I don't dive but I could use a flashlight that I don't have to worry about getting water damaged when I take a swim. 
I dropped this light into the pool a few times to test and it survived without a hitch. The included lanyard helps you locate it as well as helps it float a bit.

One odd thing is the button on this light does not click. Rather, it steps through the 4 modes (low, medium, high, max) without noise. I think this is a sealed design that helps it keep out water. Also, the rear threads are protected by 2 O-rings (vs 1 in typical flashlights). Due to all the added protection, the head is larger than typical EDC lights like the FC11. I tried to detach the head from its battery tube but couldn't. You're probably not supposed to do that due to enhanced water-proofing. Regardless, the tail cap is very well built as are the threads.

Price: $40 (with coupon)
Emitter: Cree XHP35 - 5000k-5500k
Max power: 2000 lumens

Pros (in addition to the above):
  1. The head doesn't get hot for a long time. This means you get 2000 lumens for much longer periods than pocket rockets like the D4V2, D4SV2, or even the large SP36 BLF. Those lights can only sustain their 3k+ lumens output for a less than a minute before getting uncomfortably hot.
  2. Includes charger (micro USB)
  3. Includes 3000mAh 18650 battery
  4. Includes dive/water lanyard.
  1. I am not used to the non-click button. I would prefer a twist mechanism.
  2. I would prefer some knurling on the battery tube to help with grip but I'm nitpicking here. It actually feels pretty good in hand. 
Size comparisons vs an AA battery

Cree XHP35 emitter | 5000k-5500k

High mode (1000 lumens) on WK20s vs max mode on S2+ (1000 lumens)

Here's a comparison between various brightness levels. Note that I inadvertently overexposed these a bit. The real brightness should be half what is seen here, but you can see difference in brightness levels. 
For these pictures, I set the camera to F 1.5, 1/180s, ISO 320


If you want a no-frills, waterproof (for real, not just for rain), bright, long lasting light for use around the house, this is it.

ZEROSVN Tech Enthusiast

Storage case for flashlights

Over the past few months my collection of flashlights and accessories have increased quite significantly. This means I need to find a good storage solution.

I saw some people on reddit using waterproof Pelican-like cases with thick foam inserts (the kind you use to store guns and stuff). I was going to buy one too but they're too bulky and not space efficient. I continued my search for something that fits the bill. Here are my criteria:
  1. Space efficient - it should be able to store a lot of things and not have too much wasted space.
  2. Configurable - not all compartments will be filled up and some lights are much larger than others. I need the storage box to be "flexible". 
  3. Portable - I need to be able to quickly grab it and go.
  4. Secure - If I'm putting a bunch of things into this box, I need it to be securely closed with some sort of lock so the contents don't just spill out. That would be bad. 😬
  5. Economical - a storage case for flashlight shouldn't cost more than $10. Pelican cases that can store 4 flashlights run about $50 and increase by $10 per flashlight space. Crazy
Well, I happen to be in a 99 Cents Only store the other day and came across a great solution: a configurable tools storage case that has a built-in handle.

Price: $3.99 
It's not "99 cents only" but I'll splurge 🤑

Here it is with all my flashlight sfuff:

It's filling up fast. Looks like I'll need to get another one. Or I can take the SP36 out and have enough space for the rest.

Here's how it looks without that fat boy. As you can see, this case is fully configurable by moving the orange dividers around. You can also add foam inserts to pad the bottom to prevent things from moving around.

Closed - The lid is transparent so you can see what's inside before opening.
There are 2 latches (to the left and right of handle) that lock the lid in place when closed. 

Future upgrade: foam inserts or silicone liner to prevent scratches on flashlights and to prevent them from moving around during transport.

That's it. Pretty simple, cheap, and efficient storage solution for flashlights and parts.

Let me know what you think in the comments.
ZEROSVN Tech Enthusiast

We're in a recession yet stock market is at all-time high. What?!

I've been focused on my flashlight hobby as an escape from the real world, but it's time to talk about the real world. 

Let's face it, we're in a recession. Many companies are struggling to survive; many people are out of jobs, and things are getting worse by the day. Yet, why is the stock market at all-time high? It doesn't make sense. What the heck is going on?!

I've been perplexed by this for a while and only recently did I find the answer: smart money is moving to safe havens.

Wall Street doesn't necessarily represent Main 
Street. In fact, the stock maket hasn't represented the economy for a while. SP500's performance is heavily weighted towards a few huge companies like Apple and Amazon. The people investing in them (thus driving up their prices) are mostly the top 5 investment houses, not retail investors like you or I. Surely, those people know better than to invest in highly overvalued companies right? Yes, as a matter of fact, they do! 
Here's why: the US economy is in really bad shape. It's full of companies on the verge of bankruptcy or are already in the process of bankruptcy. Things are continuing to get worse as time goes by, despite the fact that this Federal Reserve has been doing everything it can to artificially keep things afloat. However, investment money still needs to be invested (otherwise investment banks would be out of a job). It's better to put that money into large companies that have tons of money in the bank than any other option (including holding onto it). Huge companies like Apple and Amazon have so much cash that they can afford to not make money for a long time, thus making them safe bets to ride out the storms. More money invested in these companies = higher SP500 while the the rest of the economy struggles.

Oh and there's the hope that the economy will rapidly recover once covid-19 vaccine is here. That's a possibility, but one that will probably be too late for most companies out there. 


Stocks are up because smart money is moving to safe havens. Apart from the biggest companies, most companies (and their workers) are struggling to survive. We're in for a world of hurt, but the rich are doing great. 
ZEROSVN Tech Enthusiast

Sep 6, 2020

Lumen candies - My favorite flashlights

It's that time again: New Light Day!
A day when I receive new flashlight(s). A day full of anticipation, joy, and excitement... Ok, I'm not that manic but NLDs are definitely fun days. 😁

There are functional flashlights then there are fun ones. At the intersection of function and fun, you have what I call "lumen candies". Ridiculous amount of light (measured in lumens) is what drew me to this hobby, but lumen candies are what kept me here. 
Alright, let's get to my (current) lumen candies:

Emisar D4SV2 on left vs Convoy S2+
I added two batteries for size comparison. The purple 18350 is what's used inside this short S2+.
ZEROSVN Tech Enthusiast

Sep 3, 2020

Awesome all-in-one flashlight: Wurkkos WK30

As I dive deeper into my newfound hobby, I came across UV and red lights.
UV lights are used for many purposes, from verifying authenticity of money to finding scorpions and stains in the dark, but do you know why red flashlights are used? Me neither 😜

Luckily we can look it up on something called the Internet (or a "series of tubes" as some like to call it).

Turns out, red flashlights are generally used in hunting or any application where you don't want to disturb or blind your subject at night. Want to see that deer ahead without disturbing it? Turn on a red light. Wanna see more stuff at night without blinding other people around you? Turn on red light.
Here's a much better explanation of why red light is superior in the dark. 

Ok, so now you want a red flashlight. 😁
Instead of buying 3 separate flashlights to get regular, UV, and red light, why not get one that can do all 3? Better yet, why not get one that excels at all 3 functions? Well you're in luck. Checkout the Wurkkos WK30.


ZEROSVN Tech Enthusiast