Review: Magnetic control diving light (Cree XM-L T6 | 1 x 18650)

I have a new (supposedly) dive light that I'm reluctant to review because I don't dive, nor know anyone willing to take my light down to depth. I'm pretty sure I cannot confidently claim it won't flood, following a dunking in the Foytub. (phantoms 18-inches)

Still, dive lights, or those claiming to be dive lights facinate me. To me, recommending something whose failure could potentially have catastrophic consequences is a serious thing. I'm also curious if something so inexpensive could be trusted in a mission critical environment. (for lack of a better term)

divelightdummyFoy

The only things that make a dive light different from any other flashlight are the seals at the switch, the tailcap and anywhere else it screws together and the thickness of the body (prevents crushing). Right?

This light has a thick heavy body and a magnetic switch that does not permit leakage at the switch or pressure damage. Ordinary switches will not work because high water pressure will press the switch down and hold it.

The glass is thick and strong.

If you wanted, you could use epoxy to glue together all parts except the tail cap.

The tailcap is air tight and has 2 heavy O rings.

If you use heavy and sticky grease on it, I bet it works.

You choose.

Just about any flashlight is fine as far as the walls. The o-ring issue isn’t about just thicker ones or adding more. It’s about a proper design for where the o-ring sits.

Switches for the most part need to be either magnetic (nothing to leak) or twist. Water pressure activates (and leaks) with most other type of switch.

Glass thickness is important as it relates to depth and to how robust the light will be (can you bang it around without causing a leak).

In a light designed to be a dive light most leaks if they occur come from the front.

As I understand diving lights are not always so critical for safety., YOu not always need dving flashlight in conditions wich are so dark or something that this would compromise your safety.

Thats one thing - and other thing - I just cant believe that it is oh so difficult, if you have resources, to design really waterprooof diving flashlight. I just cant imagine (and I have storng imagination :slight_smile: ) that this is so hard.
I think thats more question of hastiness, that Chinese make all these things to hasty, to fast, and design them to hasty, and diving light s are the stone on wich they stumbled, because they are tricky by themselves (they mustnt leak :slight_smile: )

I dive at night (often) and deep and I don’t consider a dive light “life support” equipment. I also always have a backup light so that concern is overrated IMO.

It’s not hard to design a dive light. The main problem with the Chinese lights is that those designing the lights aren’t divers and divers as far as I can tell don’t test them.

They just use a pressure pot so that the light can experience the same pressure it will experience at depth.

It’s not hard to design a dive light but it is hard(er) to take a light that isn’t designed as a dive light and make it a dive light.

If it doesn’t have the proper o-ring cut out design behind the lens then you are left with marine grade silicone sealant or epoxy as the method of sealing.

If the switch is a “clicky” type it is going to leak and depending on type it is going to either always be “on” or always be “off”.

How much the light cost has nothing to do with how good a dive light it is however.

I replaced a $300-$400 HID dive light with a $100 Chinese LED dive light.

Perhaps we should make a thread discussing what makes good diving flashlight design and let’s hope manufacturers/dealers take notice.

Some things I got from reading in this forum. One is that you can’t have mechanical clickies so magnetically/electronically controlled switches is the way to go. Two, can’t use the metal body of the light as part of the circuit. Three, it should accommodate at least two batteries for longer run times. And four, o-rings, o-rings, and o-rings.

What’s the weakest point in diving lights where water commonly seep in?

Thank you guys. Shows what I know about diving. Seems my concerns were unwarranted.

learningFoy

It would be from the front of the light since in a well designed light there either wouldn’t be any other place for it to come in or if the light is made of several pieces (and could theoretically leak) it doesn’t with any kind of reasonable o-ring design.

So, it’s the switch (but this isn’t an issue with a well designed dive light due to the kind of switch chosen) or it’s front water pressure against the front lens letting water get behind the lens due to a bad o-ring design in the head.

Typically, a good design is a groove in the head on a ledge which you drop in an o-ring so as pressure (on the front glass increases) the o-ring has no where to go and compresses to counteract the forces pressing against it.

Therefore, the deeper you go the more pressure against the front lens the more the o-ring compresses and … no leaking.

Many backup dive lights are made of only two parts…a body and a screw-on head (and front lens of course). So there is no switch to leak.

You fully screw the head in to turn the light on and slightly unscrew it to break contact and turn the light off. In this design you have a long section of threads connecting the head to the body with thick o-rings (sometimes 2 although multiple o-rings isn’t necessarily better).

The best backup dive light I have is made of Delrin for the body and metal for the head. The lens is 6mm thick and the head diameter is only about 30mm.

This light is a tank in effect. It’s the Ultrafire W300 from DX and it’s $36 using 3 AA’s and a XP-E (XR-E?). It’s a nice, tightly focused light. Since it uses primary batteries you don’t have to remember to charge it so it’s alway ready (it’s a backup after all).

I clip it to my shoulder strap and have a small bungee around the head as well so I forget that I even have it on.

For a primary light I use rechargeable batteries (18650) and two are needed IMO since a typical dive is close to an hour and it’s not uncommon to do two dives back to back.

For a primary dive light I’d like for it to have a magnetic switch. The one thing to tells me that most Chinese lights aren’t really designed by a diver is that many of them still have crenelated bezels which are totally useless (and a hazard) on a dive light.

Sharp edged heat fins are a nuisance as well and aren’t needed since the light is being used in water. Frequently the front glass lens isn’t as thick as one would prefer for a dive light.

This is all basic stuff so for the manufacturer to not realize this means that no one has a clue about diving.

Since there seems to be some interest on this subject I’ll describe an experiment I once did.

I wanted to learn more about the failure modes of a light converted to a dive light. I used a cheap Rominsen RC-K4 (or something like that). It was a 3 AAA XR-E light with a reverse clickie.

The switch was removed which left a hole in the tail which I filled in with marine grade epoxy. This left the light as a “twisty” by screwing in and out the tail cap for on and off.

The front lens was very thin, maybe 1 or 1.5mm. The o-ring in the head was useless both because it was so thin and because of its location. It was around the lens in the head rather than behind the lens so it really did nothing to keep water out except for maybe light rain. It was more like a gasket than a compressible o-ring.

I removed the o-ring and used marine grade silicone sealant around the edges on both sides of the lens.

Then I tested this light on a night dive to 100 fsw (feet sea water). I expected it to fail but I wanted to note at what depth it failed and what exactly the failure modes were. I had another light with me of course (2 more actually).

Initially, I turned the light on before I entered the water to eliminate the act of twisting the light on as a failure point. I check the front lens every 30 feet or so on the descent to 100 fsw to look for leaks.

It never did leak! At 100 fsw I decided that I had learned all I needed to know and was therefore willing to twist the light off and then back on. It still didn’t leak. Twisting the light on and off at 100 fsw was the worse case scenario (for this test).

The lens was thin but the head diameter was only 30 mm or so and thickness is a function of surface area for these purposes so it worked but wasn’t ideal.

I didn’t bang the light around or bump the lens against anything underwater or it may well have failed.

That’s what’s not generally tested in a pressure pot…dynamic pressure rather than just static pressure.

Rarely is the issue (for leaking) with a light the body tube head or tail connection. Almost all lights have one or more o-rings there and long enough threads that there is an effective seal. Grease is helpful but that isn’t what seals at 100 fsw or at any real depth underwater.

Switches that are desirable in non-dive lights aren’t desirable in dive lights due to increasing water pressure which would activate the switch. With a reverse clicky water pressure would keep the switch from ever turning on.

Due to the way these switches are constructed water would almost always leak (flood) in at some depth and that would occur fairly quickly (at a fairly shallow depth). Spring pressure could offset that initially.

A thick front lens is desirable but it may not initially be the cause of a leak (may not break initially if not banged around).

Many dive lights are spec’d to 300 fsw so they can be used in reality down to 200 fsw or less.

I’m sure (pretty sure) that the Rominsen would have failed (lens broken) by 200 fsw. My regular main dive light has a lens that is only 3.5 mm and that’s with a diameter of close to 50mm. I wouldn’t be comfortable with it at 200 fsw.

People have had them down to 150 fsw or so. I’m had mine down to 130 fsw. The light I had before my current main dive light was taken down to 200 fsw several times and I had no problem doing that but it was thicker and all plastic (HID not LED however).

Your average flashlight may do OK in a swimming pool (or it may flood) :slight_smile: That’s an addition 1/2 atmosphere at most. Beyond that most lights would fail (and/or not work) just because of water pressure and the clicky switch.

I don’t know exactly how a Zebralight (for example) is constructed but conceivably it could work with the electronic switch (not sure about how the switch is sealed) however it would be continually changing modes due to water pressure but otherwise it might make it to 100 fsw. I’m not going to test this however! :slight_smile:

Great info gcbryan, and interestng read :slight_smile:
Why dont you get some cheap diving lights for testing (there are several of them now wich look serious, in price range cca 20-30$ ) :smiley: (I think primarily on this one, and there is Yezl Q2 for example on cnqualitygoods…
Maybe manafacturers can send them to you for reviewing (hmmm, if they dont think that wouldnt be in their interest :o)

I just dont understand the issue about body of the flashlight being part of the electrical circuit.
Im aware that this is so in practically all “surface” flashlights I own.

But I dont understand what happens with diving flashlight in that regard:
DO all budget diving flashlight have that design flaw? (XTAR lights for example? D06? YOur MC-E flashlight, gcbryan?
And what happens, why is this a flaw? (I think there are two things: Ive read for example that dinged XTAR D06 will shine in salt water even in off position, and will shock you if you touch iit with bear hands - thats one thing. And new sturdy Trustfire diving light doesnt want to change modes in the water, thats the other thing I think is connected with that flaw…)
Where the current flaws in better diving flashlights? Not through the body? Or they have thicker annodization?? Many things I dont understand :slight_smile:

I’ll respond to your second question first. I don’t know anything about this issue or even if it’s a real issue. Without knowing the details I tend to think this isn’t really an issue.

I have metal dive lights as well as those with a hard plastic body. I’ve had no issues in that regard.

Regardlng testing dive lights…I’m not interested in most of the ones that I see. They’re either too small (don’t have enough burn time) or they’re too floody or (the big issue) they’re just too likely to flood since it’s just luck for a Chinese manufacturer to end up with a robust design since they don’t seem to actually know anything about the issues that relate to the diving environment.

I also don’t need any more dive lights at the moment. What I have do the job and even if more “modern” lights come out what I have do the job and don’t leak so what’s the point? :slight_smile:

The only light that would interest me would be one that 1) works and 2) doesn’t have all the crenelations and heat fins that my current one has while 3) still using two 18650’s.

However, money is tight and I’m really not interested is spending $100 right now even if such a light did come up.

The big advantage of the light I posted about (main dive light) is that hundreds of people bought that when it first came out (since there was nothing close to it in price at the time) and many of those people (myself included) were in contact with each other regarding reviews, failures and fixes.

So that light is fully vetted in a way that most of these others aren’t at the moment. On the other hand if someone is just looking for a small floody light for a shallow clear water night dive on a tropical vacation…most any dive light will do that.

But you say u prefer to use your light only to 30 meters, I think? (because of little too thin front glass?)

And no o rings need to be replaced on it?

Regarding other lights issues: Loading...
Look this one is interesting. Its 1Y18650 but it can be at least spare light. Yezl is known as quality budget manafacturer, and I have read one positive comment about some Yez flashlight on scubaboard.
It doesnt have any crenelations nor “attack head” :o
It even has nice big whole fror attaching diving lanyard.
And it looks like really nice, beefy (like many Yezl designs :slight_smile: ), also like serious flashlight…

But I understand your point, you already have what you need and you are not inclined to risk and experiment.
Maybe a con is to thick bezel, or better to say to small reflector. HEad is 53mm, but reflector diammeter s maybe less than 40mm (less than C8 reflector diammeter). And it doesnt look very deep, so you want get to focused beam with XML…
And if its moderately driven you should easily get more than 1 hour runtime with one good 18650

Following your recommendation Im closest to buy this one http://fancyflashlights.com/goods.php?id=193 (same as yours, but ffrom other website - because of cheaper price)

PS: Flashligt from this topic also doesnt look bad, but because of small reflector its surelly more floody than throwy with XML (XPG or XRE would be different thing)

The first one you link to looks interesting in that it’s attractive as you say. For me it would be a bit too big for a backup light given the manner that I attach and use the backup light.

I use this as a backup light…
W200

Bryan thanx for sharing all this info, I hope more people will benefit from them.

Your backup light, based on dx reviews, has some problems and needs to be checked obefore any use.

Regarding MC-E light, do you think I need to buy some spare O-rings and where to buy them?

PS: And look at this cute diving headlamp :smiley: ) Loading...

This is a subject matter (diving and lights of course) that I do find interesting and do have a decent amount of experience with since I’m into diving and fortunate to live where deeper ocean diving is possible on a daily basis if I so chose (and I so chose for quite a while) :slight_smile:

Ecig, I don’t personally regard the W200 as being anything but rock solid. Some people have had a few problems which is the case with anything from DX and probably with anything in general.

Some of the people who had problems with the W200 did so after taking it apart. It’s not designed for that. The way the front is put together works well but if you pop the o-ring out and scratch it and then put everything back together it could leak.

That’s not a problem with the design of the light. I have two of them and did take one apart to play around with (modifying).

Although it’s possible that someone could have gotten a bad one. Most of the issues of that light leaking only came after everyone starting buying that light to modify. I think most of the issues were caused by trying to modify it. The o-ring in question in that case is a press fit from the front on top of the front glass lens. It’s what keeps it in. It’s a different design from most lights.

Foy, that looks like a good light. There are several designs out there that look like a good light and they may be. They only way that I consider them to be good for diving is if a lot of divers bought them and went diving with them over a period of time and there was no major problem with leaking.

There aren’t many reviews of most lights since the model that I have. Since there aren’t many (in some cases any) reviews when there are leaks it’s hard to know if it’s a common problem or just an isolated one.

If these lights were being made by the usual dive light manufacturers I’d assume a good looking design was probably a good dive light.

That’s not the case however. The people making these lights aren’t divers and don’t really know anything about diving.

The guy who originally designed the light that you have is a diver however he didn’t manufacture that light so …who knows?

There are several models of that light however in various configurations. For my purposes it’s not a backup light (too bulky) and unless it can take two 18650 it doesn’t have enough power for two consecutive dives (which is common).

I don’t know why he designed it with all those cooling fins with their sharp edges. He was more interested in cave diving and may have also wanted them to burn brightly while out of the water as well (I don’t know for sure).

Ecig, regarding diving headlamps…ugh! :slight_smile:

I absolutely hate it when a dive buddy wears any kind of light on his head to the point of just not preferring to dive with people like that.

Every time someone like that looks my way that means his light is shining in my face! The same goes from people who decide to wear a flashing strobe on their tank or somewhere on their body to supposedly help someone locate them!

It’s annoying! :slight_smile:

Oh, regarding extra o-rings for the Magicshine light…it comes with several extras. Some people were talking about getting something harder than the silicone ones that come with it.

I don’t think that’s necessary. If you want to do it fine but I have hundreds of dives on mine with no problem.

You know how this goes…people like to mess with/change whatever it is that they buy. Sometime/often they cause the problem that they are complaining about. :slight_smile:

I think there are plenty of examples of that right here at BLF. :slight_smile:

I’m not immune either. :slight_smile:

Hi, this diving flashlight what a gift to a friend of mine. One day, he did sth stupid with the batteries and as s result, he destroyed the driver.

As you can see in the pics, the driver has the magnetic sensor of the switch.

I tried to fine a replacement with no result. Do you have any idea where can I find this type of driver? Is it possible to repair the fried driver?

Maybe to ask Ric at cnqualitygoods?

And what you think about these. ?page=1#comment-221088

Same Magicshine flashlight (same body) but with XML

Lightmalls has incredibly good price, but its maybe some cheap low-qualitxy clone with all different internals (o-rings etc) than real magicshine.
Magicshine is it appears seriously in this busyness and they have even one new, I think, mode, SST50, with flat bezel, 2X26650, but little out of my budget currently.

It would be great if lightmalls flashlight is any good because the price is great (but I described everything in that other topic

maybe you can use any driver, adding the magnetic sensor

magnetic sensor (italian)

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