Lights 101?

[stuartv]

Is there an article or post somewhere that you would consider a basic Intro to Scuba Lights? I can't find one.

Obviously, the kind of article I'm looking for would be written for an audience of new divers (like me). Questions I would hope to find answers for include:

- What light technology should I be looking at. LED seems like the obvious answer.

- Should I buy something that uses alkalines or rechargeables or something that can use either? What are the tradeoffs? What are these rechargeables I've seen references to like "18650"? I've never heard of that.

- What constitutes a Primary light, versus a Backup? I see the DGX 600 claims to be the "brightest backup light they've ever offered", yet the next light down the page is the BX-1, which appears to be virtually the same size and brighter - a lot brighter using the rechargeable 18650 battery. As in 600 lumens versus over 1200. So, is their webpage just BS, or is the BX-1 considered a "Primary" light, so the claim about the DGX 600 is technically true because it's a "backup" light?

https://www.divegearexpress.com/lights/backuplt.shtml#4087

- Which light(s) should be a spot light versus a flood light? Should primary and backup both be spots? And what beam angle is still considered a spot? I see the Light and Motion GoBe lights that have a "spot" that is 20 degrees where most other spots seem to be in the 6 - 12 degree range.

- What about a light with a focusable beam, like my Mag-lite? I don't seem to see anything like that for dive lights.

- How many lumens do you need for a Primary? For a backup?

- I want to dive with my GoPro, in the Caribbean, and be able to record stuff when I'm at 60' depth and the subject is under a rock ledge. What beam angle should I have and how many (minimum) lumens? And would that light then be proper to consider as my "primary", or is that a "video" light and I still need a proper primary and a proper backup?


Remember, I said the target audience for answers to these questions is people who just got their basic OW certification. So, they might be looking at wanting to take pictures or shoot video with a GoPro. They might want to do a Night Diving course. They might be looking at taking Underwater Navigation, possibly in low viz water. But, we're not talking about deep diving, cave diving, wreck diving with penetration, diving with doubles or deco, or other Technical stuff. Just, what do I, as a new diver, need to know to choose some lights for myself that will be useful in, say, my first 25 - 50 dives going forward, yet, hopefully, not thrown away after that? And definitely not purchased then never used because I simply bought the wrong thing.

I have read enough in this forum to have some ideas about the answers to some of these questions, but it seems like I would be able to find a basic article on scuba lights that would explain a lot of this.

I had the good fortune to do a day of cenote diving last week and my instant dive buddy offered to loan me an extra light that he had and wasn't going to use. It was a Light and Motion Sola 2000 F/S. I had no idea how lucky I was at the time. I just saw that it was like a small sun compared to the wimpy lights that our guide provided to the other divers in our group. Now that I'm home, I see how expensive that light is and think surely I don't need to spend that much money to get some suitable lights for the diving I'll be doing over the next year (or two). But, other than sales pitches and bits and pieces scattered across many threads here, I can't seem to find solid info (with numbers) on what I should really be looking for that will actually be useful to me.

Thanks for any help.

---------- Post added December 30th, 2014 at 04:28 PM ----------

Is a light like a Sola 800/1200/2000 actually a good investment because switching between 3 power levels and between Spot and Flood means you can use it in lieu of buying 2 or 3 separate lights? I.e. One Sola would save you buying a separate high-powered spot for serious penetration in low viz, a low-powered spot for normal use with a long runtime, and a medium to high powered flood light for taking pictures or recording video?

Or should I be looking at buying a high-powered spot primary, a smaller, low-powered spot for backup, and a bright flood for pictures/video and having a bunch of change left over? And then maybe only carry the high-powered spot OR the video light, depending on what I'm doing, and the backup spot always?

 

[tbone1004]

LED, no point in any other technologies at this point in time for new divers

For non overhead diving, video spreads are generally preferred as they tend not to blind fish and other divers, you also see more. If you're planning on going into overhead, you need a spot to signal your buddy.

18650 is the cell size for most lithium polymer batteries, including most of the canisters, they daisy chain them in a combo of series and parallel to up capacity. Most backup lights are going to 18650 cells instead of 3 AA's or C cells due to cost. These are much more reliable than the older NiMH rechargeable AA's that are frowned upon in backup lights. For primary light use, rechargeable is better, and even for backup use most are accepting Li-Po as reliable enough for backup lights.

Dive Rite quotes their lights in lux, not lumen. Unfortunately there is no way to go back and forth, but they are using the same LED module, so the light outputs are about the same using the same 18650 battery. No reason to use the AA's other than for convenience if you don't have access to power, but 18650's are cheap, carry two, nbd. Buy the DGX light and save $25. The 600 lumens out the front is normal, even though dive rite is claiming however many lumens they are claiming, they are only quoting raw lumens, not lumens out the front. Same LED module, same voltage, same beam angle=basically the same light

Primary vs. backup. The only reason primaries are generally canisters is because battery technology isn't to the point where you can get enough burn time out of a handheld light yet. The light output doesn't matter, burntime does, at least in overhead environments. As you aren't in one, there is no point in getting a canister light at this point in your diving.

Pistol grips are absolutely idiotic

OW divers wanting a light should look at the DGX600 first because it's cheap, good, and that's about all you need to know. Buy the soft goodman handle for $10 and for $60 you have a light that is quite bright, quite small, very cheap, and will last basically forever, and is also super convenient because you still have your hand free. For recreational divers, you can carry a spare if you want, but likely not needed. Other comparable 1000lumen ish lights are out there, Hog Morph 1000, DRiS has a few different ones, BX-1 though over the DGX600 you're just paying for the brand name. They mostly use the same LED module, and most use the 3.7V 18650 batteries, so aside from beam angle there isn't a whole lot of variability.

These lights are mostly spot lights meant for backup lights for technical divers. As such they aren't the best for gopro type applications because you have a hot spot in the middle which will be overexposed, it can also blind fish, which is bad. For this, the Hog Morph 1000 has a 72* beam angle and the DRiS Impact stubby is 140* beam angle. The Morph 1000 video is probably the best for normal divers to start, downfall is it is $150, but it is button vs. twist off, and has a better beam angle for normal recreational dive profiles. These lights can also be used on land, so they can replace normal flashlights for day to day use around the house.

No need to discuss primary canisters because that is a large can of worms and luckily for this, the backup lights we are using are all about the same since the LED module is the same between most of them.

 

[stuartv]

tbone, you are the Man! Thanks again for taking more of your time to educate me!

So, the DGX page for lights says, right at the end of the LX20 description, that approximate lumens can be calculated from the Lux (by dividing by 10).

So, they say the DGX600 is 600 lumens and the BX-1 is 12400 Lux (with a rechargeable battery), which translates to approximately 1240 lumens. So, from their own information, they seem to be saying the BX-1 is roughly twice as bright as the DGX600. But then, both lights do say that they use the XM-L2 U2 LED. And both have an 8 degree spot beam. So, the only way they could be different is their optics (reflectors and lenses).

The BX-1 does look (in the pictures) like it might have a bigger reflector and lens assembly, so maybe it might put out a little more light? But, given the same LED and battery, it sure does seem unlikely that it would put out twice as much.

The BX-1 claims 4 hours of burn time with an 18650 and the DGX600 only claims 2 hours. I'm guessing they are measuring those burn times differently. Or the electronics are very different. Do you have any insight on that?

My gut is telling me to get the one that will let me use regular alkalines, for the occasion where my rechargeables are dead and I can't or don't have time to charge them before I need to use the light. Like, when I forget to charge them the night before a dive, for example, and want to just grab some AAAs in the morning on the way to the boat. Is that worth an extra $25?


Beyond that... This is what I seem to be getting:

For OW, warm water dives during the day, I would not really even have a use for a spot light. It seems like all I would really use is a video light (for OW day dives).

For OW warm water night dives or cavern (e.g. cenote) dives, I would need a low to mid power (e.g. 200 - 600 lumens) spot, for signaling, and a video light.

So, it seems that if I get a Morph Wide and a DGX600 or BX-1, I would be pretty much good to go for $200 to 225, yeah?

When I get around to trying night diving, I can just buy a small, cheap marker light for my tank (I read that many places don't allow glow sticks) and still be good to go, right?

How usable is the Morph in the Goodman glove, when it has the Backup body attached? It looks like it could be long enough to be interfered with by my arm if I'm trying to angle my wrist upwards.

And you cited having a push button switch as being a benefit over twist off. Is it? Why?

Lastly, what about BigBlue lights? I stopped at my LDS on the way home. They said they used to carry the L&M lights but stopped because the charger connection was very finicky and the lights weren't that durable. They were pushing BigBlue and the VTL2500P or VTL2800P looks like it might be nice, though definitely pricier. It looks like maybe I could get a 2500 for around $370, as a Closeout. But, it uses the 32650 rechargeables, is 2800 lumens, and is switchable from 120 degree beam to 10 degree spot (only 1000 lumens). I definitely like the IDEA of being able to switch from a spot, when just looking around, to a wide angle when I see something I want to record. But, I realize the idea often doesn't pan out in the real world.

So, do you think the extra investment in a light like this would pay off later, if/when I get to the point of taking a Wreck Diving certification and start trying to do things like that? Or diving more cenotes or other caverns? Or is it just a waste of money? Maybe it would save me from buying a Morph AND a DGX 600, as it would cover both bases for me, so I could only buy one light?

 

[elgoog]

tbone got you a lot of the information you were looking for so I'll add a little bit about a couple of the lights you mentioned, from the limited experience I've had with them. I think we're both at very similar levels in our diving careers and a lot of the use cases you mentioned are what I've done or am looking at doing in the near future.

DGX600 (tl;dr - cheap, good battery life, good for navigation+low viz, marginal for photo, bad for video)
1. Terrific value for money, especially considering it comes with a battery and charger.
2. Performance in low viz is quite good. Wifebuddy and I did 2 of our Navigation dives with this in ~10ft of extremely murky viz in Monterey and thought they were great in those conditions. The other 2 Nav dives were in Lake Tahoe with a lot better viz but it got dark really quickly at the ledges - in ~50ft of water you couldn't see much beyond 20ft but with the light, that easily doubled. I've not been on a night dive but this was the darkest dive I'd done.
3. Battery life is easily enough for 2 dives on a single 18650 battery (switch light on at 20ft, switch off at safety stop). Even at the end of the 2nd dive, we didn't notice any major drop off in light output. Bottom times for all dives were in the 35-45min range. I think you could probably squeeze in a shallow/short-ish 3rd dive in with the same battery. If you don't have extra batteries or are unable to charge the ones you have for some reason, you can use 2 CR123 disposables in the DGX600. I confirmed with DGX that the higher voltage using the disposables is still within spec of the circuitry, so you won't fry anything. I have not actually done this on a dive so can't comment on the battery life.
4. Super compact and easy to stow in a pocket or clip off on a D ring. Even 2 in a pocket is easy.
5. The soft handle DGX has for it is OK. I felt it didn't hold the light tight enough and I always had to be extremely conscious of what I was doing with my left hand. Also, it's next to impossible to turn the light on and off when it's mounted and you're wearing it. You absolutely need two hands to operate this light and the soft handle doesn't provide enough stability or hold it in place enough for you to do it yourself. I always had to ask someone else to do that.
6. The beam is really tight and the spot too bright for photos - it washes everything out. You can kind of use the outside ring of the light but the lighting ends up being pretty uneven for stills and results are not at all consistent. Video is mostly useless for the same reason. For more context, I was operating the light and someone else was doing the photo/video. I even tried using wax paper on the light head as a diffuser but that ended pretty quickly as I had seriously overestimated the structural integrity of said wax paper after exposure to water.

Sola not-sure-which-model (tl;dr - expensive, not great in low-medium viz in flood mode, maybe too many points of failure, limited battery options)
1. Yep, like you mentioned, mucho $$$$
2. When we were doing our Nav dives, there was a group doing AOW and they did their first 2 specialty dives with us. One of the guys had a Sola and I saw him cycle through all the modes and use it quite a bit under water. From what I could see, the low and medium settings in spot were not useful in low viz, the high setting was pretty good. The beam angle looked a little wider than the DGX and the center of the spot was not as bright. There were too many particulates in the water for the flood setting to show anything. In the tropics, I saw the video results of someone using a Sola (on the same day and site I attempted the wax paper experiment on the DGX) and it's waaay better. The viz on that day was not great but all the videos he took were inside a ship wreck where it was a lot clearer water.
3. Personal opinion - all the switches and knobs and adjusty-thingamabobs scare me a little. It's too many things that could break or cause a flood on an expensive piece of gear.
4. I don't think there is the option to use any disposable batteries or carry extra batteries for these lights.

I think it would be really easy to carry 2 lights on all your dives and cover almost everything you need - a DGX600 and one of the ones tbone mentioned for video+photo+clear water Caribbean reefs use (DRIS Stubby with the video light head was what I was looking at for a Cozumel trip this summer and it also uses the same batteries).

Hope this helps,
elgoog

 

[tbone1004]

the DGX should be a bit brighter since the module has been optimized for brightness over burn time, but they're going to be fairly similar. If you think the AA option is worth $25, then go for it, not going to matter much either way.

In OW night environments you shouldn't be far enough away from your buddy to need to signal, you should be next to each other and not out of touch distance. In a cavern you should have some sort of spot function.

Some divers have issues with twisting the twist on/off lights the wrong way, it has flooded many a light, and for recreational diving, the push button feature is nice.

Piranha has glo-toobs that use a AAA battery and work well, about $25 I think.

Works fine in a goodman, they usually offset them a bit towards your index finger, but you aren't normally lifting your wrist up, and since it is neoprene it will stretch.

re. adjustable, it worked decently well with the HID's but there really isn't a point, you either have video lights, or penetration lights, better than jack of all trades master of none.

If I was spending $300 on lights I would get a video and a spot Hog Morph. You can use them as backup lights in overhead environment training, they use the same battery/charger, and you can buy the Morph system to put one on a canister for longer burn times or mount both to a gopro rig. Alternatively buy the video hog, and either the BX-1 or DGX600 to save a few bucks, doesn't matter either way, can't go wrong there, you're doing dives long enough anytime soon to need the burn time of a canister, and these little backups put out a lot more light than the old 10W HID's that many of use were using for a long time in the caves *these were under 150 lumen btw, with a peak lux of 650 give or take*

The BB lights don't look that bad, but for the price I'd rather get a non discontinued light using standard optics. You'll be surprised at how nice the video light from hog is if you choose to get one.

also, VTL2800P for $330
Big Blue Open Box/Demo/Like New VTL2800P Adjustable Beam Dive Light - with reviews at scuba.com

 

[lamarpaulski]

LED.
For use with GoPro you need a wider angle than many dive lights give or else you get hot glaring spots and dark spots...I use a Morph back up with 'video' head..works pretty good also gives enough light for the dive. Rechargeable. But i carry a back up and you ought to also..which would let you maybe have different types of lights and enjoy recharge/regular..video/focused etc etc..I carry an UK standard battery LED 'spot' light for back-up and its rugged and long-lasting and bright..just in case.

Rechargeables generally run out of juice quicker than a light with a good set of standard batteries. Not as big an issue these days as newish LEDs use less juice and will last most people's entire dive. Nonetheless, for a very long dive or couple back to back night dives an LED light with a fresh set of good regular batteries would be my preference over rechargeable types.

The above-mentioned lights aren't too expensive and would be a good starter so you can gain experience and see how committed you are to diving/video/ etc although I have not heard a bad word about the light monkeys except a bit pricey.

 

[stuartv]

Between tbone and this right here:

you can use 2 CR123 disposables in the DGX600

I'm just about convinced on a Morph Backup Wide and a DGX600.

Thanks, guys!

 

[tbone1004]

grab one, probably the morph. Oh, fwiw
Gopro viewing angles
Wide-114*
Medium- 95* ish
Narrow-74*
Keep that in mind as you are choosing lights.
Impact Stubby from DRiS is 140*, Hog is only 72* so if you use it on wide or medium you will have dark spots in the corners. Just something to think about as you are playing with this. The Morph works pretty well on medium but you really need two to keep it happy in wide.

 

[jzipfel]

I have four of the Mako lights. 2 for me and 2 for my son. They do use 18650 but CR 123 can be used too.

The 800 lumens and 150 degree angle are really nice. I have used them in Hawaii and Murky Puget Sound and I really like them. Two in tandem work really well too.

 

[stuartv]

I have four of the Mako lights. 2 for me and 2 for my son. They do use 18650 but CR 123 can be used too.

The 800 lumens and 150 degree angle are really nice. I have used them in Hawaii and Murky Puget Sound and I really like them. Two in tandem work really well too.

The only lights I see on their website are a 680 lumen spot light and a 890 lumen 110 degree light. Do you have something older and out of production?

For $73, I'm really thinking about the Mako 890, instead of the Morph Backup. Especially when considering the Field of View angles that tbone posted.

And then a DGX 600 as a backup / spot light.

They both use the same batteries, too, so the charger that comes with the DGX plus 2 or 3 extra batteries should have me ready to rock.