First, the brightest LED emitter I know of that is currently available in a dive light is the Cree XM-L2 U3. The max they put out is just over 1000 lumens.
If you look at the DRiS 1K and the DGX 600 and numerous other popular non-canister lights, they all have this same single emitter. So, they are all going to be about the same amount of light. The differences are with the electronics and the reflector. Electronics might limit the current flow to the LED in order to preserve battery life at the expense of being not as bright. The reflector might project a wider beam which won't be as bright in the area it lights up - it will just light up more.
I have been using the DGX 600 for over a year. It's a great light. I got Sanyo 3400mAh 18650 batteries off eBay (which actually test out between 3300 and 3400) and the DGX 600 has always lasted well more than just one dive.
At $50, with a battery and charger, the DGX 600 is really hard to beat.
DGX 600 Handheld Light | Dive Gear Express®
However, it is not perfect in all respects. I recently got an Xtar D26 to try and now that I have tried it, it has replaced my DGX 600s as my primary light. The D26 is the same single LED emitter as the DGX 600, so they both have the POTENTIAL to be just as bright as each other (or the DRiS 1K).
The beam angle on the D26 looks almost identical to the DGX 600. It's tight. I think it's actually just a smidge tighter than the DGX 600, but close enough to call it a tie.
The D26 has the following advantages:
- Turn it on and off easily with just one hand. It's a push button on-off. The button can be twisted to lock it, to prevent accidental on or off. The DGX 600 requires me to use 2 hands to twist it on or off.
- Multiple brightness levels. The max is slightly (just barely) brighter than the DGX 600. But, you can choose from 4 levels of brightness, which can be really good for really making the battery last, and also for not being too bright, in case, for example, it's a night dive and you don't want to blind the critters. The DGX 600 has just one brightness level - BRIGHT!
- Uses a 26650 battery. So, it's the same LED emitter as the DGX600, but a bigger battery, so it will last a fair bit longer than a DGX 600, even on the same brightness level. I got some Soshine 5500 mAh batteries for this light and they all test between 5100 and 5400.
- It has a threaded hole on the bottom to fit a standard tripod mount. I'm not using this (yet), but it does give mounting options that the DGX 600 does not.
- It comes with a spacer sleeve that you can use to allow you to run 18650 batteries in the light, if you need to.
- It has an LED near the power button that illuminates in different colors to indicate battery level.
The only disadvantages I've found in the D26 versus the DGX 600 are:
- It's a little bigger. But, it's still only a 1 cell light and the cells are the same length. The 26650 is simply fatter than the 18650. I think it's a very nice length for clipping to a shoulder strap D-ring on my chest.
- It's a little more expensive. But, it's still under $60 on eBay - but with no battery or charger.
I'm not super experienced as a diver and I have not tried very many different lights. But, that said, I would absolutely, highly recommend the Xtar D26 as a primary light in the Under $100 category.
