The discontinuation of Inon’s S-2000 strobe is leaving a gap in the affordable-end compact strobe market. The Inon S-2000 was probably the world’s best-selling underwater starter strobe due to its price tag and size. While we are waiting for what Inon might bring as its replacement the AOI’s UCS-Q1 compact strobe might just take its place on the market. The other comparable strobe is, of course, the Sea \u0026amp; Sea YS-01 Solis. The AOI UCS-Q1 is however more affordable than both of these. The Q1 has been been a popular seller in the far east market for a while now. Lately, it has also been increasingly available in the “west”. Here I’m having a brief look if this diminutive strobe is worth considering.\nDimensions and output\nThe AOI Ultra Compact Strobe Q1 is only a tiny bit bigger than the well-known Inon S-2000 and weighs approx. 420 grams without batteries, compared to the S-2000 which weighs 350 grams. In water with two 18650 li-ion batteries, the Q1 weighs only 90g. The Q1 promises a max guide number of 22. According to my tests (done with my Minolta Flash Meter V) the Q1 output is roughly the same as with the S-2000 and The YS-01 Solis. These strobes on paper are GN 20 strobes so AOI might be overestimating a bit. Still a decent output from a small strobe.\n\nThe SQ-1 comes with a dual-LED spotting beam, which is very powerful at 700-lumens. Worth remembering that the Inon S-2000 doesn’t have a spotting beam at all. The Sea \u0026amp; Sea YS-01 spotting beam is only about 200 lumens.\nPower Source\nMost underwater photographers are used to the idea that their strobes run with standard AA batteries. This makes the batteries and chargers easy to source almost everywhere in the world but come also with a downside. Depending on the type of AA batteries the number of flashes can be as low as 50 per charge. The UCS-Q1 however runs with two Li-ion 18650 battery packs. With two 3500 mAh 5A batteries, you can fully discharge the flash more than 1500 times. In theory, one full charge could last the whole liveaboard week! This can be a huge benefit as charging batteries between dives is always a pain in the backside. Various 18650 cells are easily available today and are often used to power dive torches so you might already own a few. Also, recent arrivals to the market are the special 18650 Li-ion battery packs that do not require a separate charger. Instead, they have a small USB port that can be used to top them up. Just note that not all 18650 are exactly the same length. The longer “button-top” versions should be used.\nUsing the UCS-Q1\nThe AOI Q1 strobe is marketed as a starter strobe and is easy to use. On power-up strobe automatically analyses the camera’s flash (single or pre-flash) and adjusts accordingly. There are no automatic S-TTL models like with the S-2000. Here you simply adjust the strobe’s power up and down from the main dial. You have 7 different power levels to choose from. A short press of the power button switches on the spotting light with three different power levels. The strobe ships with a diffuser that should be kept on. A Standard 1” ball mount is supplied and most standard fibre optic cables are compatible.\n\nFor macro enthusiasts, there is also a simple snoot attachment available. The snoots are notoriously difficult to aim correctly underwater as you often don’t see the spotting light through them. AOI has solved this issue with a special strobing mode they call “modelling flash”. By holding down the “test” button the light emits a high-frequency stroboscopic pulse that lasts about 2 seconds and allows the strobe to be aimed even with the snoot attachment.\nFinal Words\nAlthough AOI might not be the most well-known name in underwater photography they have been making underwater photography products for a long time for other companies. For example, they are behind Fantasea housings and pretty much everything sold under the name Backscatter is also made by AOI. The Q1 is the first strobe from the company that carries their own name.\nThe UCS-Q1 is priced at around £300 in the UK. That is an excellent price point considering the nearest Japanese competition is at least 100 pounds more. The Q1 is exactly what the doctor ordered. A small, affordable, well-built unit for divers who want to get started with underwater flash photography. With decent-quality Li-ion battery packs (not included with the strobe) you don’t have to constantly worry about battery changes. The spotting light is powerful enough to double as a dive light. The only thing the Q1 is missing is the automatic S-TTL mode. If you especially need this then you will need to spend more.\n \nSee the AOI UCS-Q1 Strobe HERE at Mike’s Dive Cameras. Also available as an arm package HERE.