Quick Review: Weefine Smart Focus 10000 Video / LED strobe light

A few years ago, on this blog, I reviewed a light called Weefine Smart Focus 6000 that promised to be a unit that would combine underwater video and strobe light into one package. After my tests, it became evident that these new types of underwater lights, that provide a fast blink of light from their COB LED light sources, would not fully replace the need for “old school” flashes in underwater photography. The 6000-lumen flash of light simply didn’t compare with the output of what even a basic electronic flashgun with a xenon tube could produce. However, I did find that the Smart Focus 6000 was quite a handy tool for close-up and macro photography, where even somewhat lower output can provide decent results.

Weefine has now introduced a new even more powerful Smart Focus light. The top of the range model is called the Smart Focus 10000 and comes with even more muscle. This all-singing model comes with even more options, a larger battery and a glass dome port. It will be a superb video light for sure. Could 12000-lumen LED “flash” now be comparable to a traditional flashgun? This is what I set to find out in this review.

Weefine Smart Focus 10000 features.

For 2022 Weefine has re-structured their Smart Focus range that now includes the super-popular Smart Focus 2500 video/spotting light at the bottom, the intermediate Smart Focus 5000 and the 7000 with the flash function and the brand-new Smart Focus 10000 with a completely fresh design. The previous Smart Focus 6000, which was externally identical to the 5000 and the 7000 has now been discontinued.

The Smart Focus 10000 is a fair amount larger unit than its siblings and the most striking feature is the glass dome port that will keep the beam angle super-wide even in water. The unit weighs 825g on land and lots of that bulk comes from the new sizeable 5000mAh Li-ion battery pack. In water, with the battery, the light weighs 380g.

As the name says the max output of the light is 10000-lumens on flood mode and according to the manufacturer the light temperature is 5000K (CRI: Ra80). In my tests, the Smart Focus 10000 was considerably warmer than electronic flash units with 5400-5500K colour temp. You should be able to run the light on full power for 50 minutes on one charge. The number of flashes you can blast out with one full charge is in thousands.
The light also comes with red, blue and green LEDs that are sprinkled around the large central light source. The red and blue lights do, of course, have practical uses in water but the green I think is just for fun. You can mix the different colours together, which allows the light to produce various colour combinations... I guess these could have some use in creative background lighting, for example.

Flash modes on Smart Focus 10000

According to the manufacturer, the maximum “flash” output of the light is 12000 lumen, 2000 lumen more than the unit can produce on constant floodlight mode. You can also set the light to emit a lower power “modelling” focus assist light beam with the flash mode. This also works with the other colour modes... for example, you could have a red focusing light on with the white main flash. Great for night diving. Alternatively, you can use the Smart Focus 10000 (and all its siblings) as AFO focus light, where the light quenches itself when it senses a flashlight being fired. For all these functions you will need to connect the light to your housing with a standard fibre optic cable exactly as you would do with a regular underwater flash unit.

Flash tests

Like with the previous Smart Focus light, I used Inon S-2000 flash as a comparison in this review. The Inon S-2000 is one of the most sold underwater strobes in the world and super popular, especially with underwater macro photopapers. I also used my trusty old Minolta V flash meter to see the exact power emitted from the light sources.

In my first experiment, I positioned both the lights 10cm (a realistic macro photography distance) from the target to see what kind of exposures they give. On full power (camera at ISO100) the Weefine Smart Focus was able to give good exposure at 1/200s on f16. From this distance, the Inon had to be dialled to minimum power to avoid overexposure. The big difference was that from 60cm away the Inon S-2000 could still provide a decent exposure with the same camera settings whereas the Smart Focus couldn’t. From 60cm away the frame was heavily underexposed with the Smart Focus. The distance and small aperture were just too much for the LED flash.

With my Minolta Flash meter on ISO100 from 1m away the Smart Focus gave f2.8 at 1/250. The Inon S-2000 gave f11 (or -0.7 stops less with the diffuser on). What one needs to remember is that a blink of light from a traditional flashgun is very fast. In a darkened room you can have your shutter speed well beyond 1/1000s second before you can see the shutter clipping on the exposure (with a curtain shutter, things are different of course, as you can’t generally push the sync shutter speeds higher than 1/250s). But this is not the case with the LED flash of the Smart Focus 10000. At 1/250s the light is seriously clipped. The exposure creeps up until to about 1/20s of a second and then stays the same beyond that speed. This means that the flash duration from the Smart Focus 10000 is somewhere between 1/20 to 1/30 of a second (my flash meter jumps from 1/32 to 1/20 so it is difficult to say exactly) which is an extremely long time in comparison with a traditional electronic flash. At 1/20s from the same 1m distance, the Smart Focus gave f8 and Inon S-2000 stayed at f11.

In practice, this means that when using LED type “slow” flashes, shutter speed has a massive effect on exposure. With traditional electronic flashguns, the shutter speed doesn’t really matter.

Conclusion

It should not be ignored that on the whole, the Smart Focus 10000 light is an awesome unit. It’s a compact multi-functional machine that produces a massive amount of light when needed. The LED flash mode works well and can in some cases replace a strobe, as long as the distance to the target is kept short and you are willing to use some manual settings on your camera. Of course, the Smart Focus 10000 still can’t compete with even the most basic strobe unit in power, so ignore trying to use this light for wide-angle photography.

Weefine has been pushing the technology on LED flash capable lights for some years now. Could these lights, one day, be fast and powerful enough to compete with electronic strobes? How many lumens is needed for that? 30000? 40000? LED technology has taken some huge strides in the last 10 years so I would not be surprised if we soon see such a light.

Oh, and I forgot to mention... The Smart Focus 10000s have a special 70s party mode. Get a couple of these lights together and you can have an after-dive dad-disco.

Get your Smart Focus 10000 light from Mike's Dive Cameras