Introduction – underwater strobes, in general

Until recently, the market only had big, very expensive strobes and smaller, less expensive (and less powerful) ones. All had fairly wide beams, and differences were:

  • The wideness of the beam, as mentioned, measured in degrees, most models going from 90 to 120. That is related to the transition, between the dark and the illuminated areas. Some are smoother than others.
  • What I call “light penetration”: something I cannot scientifically measure, that means how far, in all different directions, light travels away from the strobe, and how it hits the subject (being soft or harsh, at different distances). A “good” strobe, is a forgiving regarding positioning, meaning, that the image will still be usable whether I set it up a bit too close or too far, or in a slightly wrong direction. You will find a “guide number” announced for every model, which is the F/ value set on camera X the distance (in metres) to the subject. Some manufacturers announce the land value, some the UW one. I believe they all measure it differently, so it’s impossible to draw conclusions solely on that information.  (All will claim they are the ones who measure it “correctly”…)
  • Colour temperature: that is a more scientific parameter, as it’s measured in Kelvin degrees. I tend to prefer a warmer tone (less than 4500K) but in really clear waters, colour accuracy works better, so around 5000K  is the sweet spot. This is only important in situations where sunlight / natural light is used for background illumination. The White Balance should be set to the strobe announced Kelvin temperature (regardless of shooting RAW or JPEG, for reasons I cannot fully explain in this article). In this way, the subject, lit by the strobe, will roughly display accurate colours. The background, however will, as it is lit by natural light, be affected. The warmer the strobe (the lower Kelvin number), the colder the background will look, (which is flattering, for greenish waters, but awkward in blue ones, as they’ll be rendered as purple).
  • CRI or “colour rendering index”. This is not used by manufacturers on UW strobe specs, though it’s widely advertised for UW torches. Its definition is: “a quantitative measure of the ability of a light source to reveal the colours of various objects faithfully in comparison with an ideal or natural light source”. The scale goes from 1 do 100 being 100 the ideal value. In my words, a good CRI is one that shows all rainbow spectrum colours at the right proportions. I had, some years ago, an UW strobe that wasn’t able to display cherry red. The images, either came out brownish red, or purple red. I had to build a Camera Raw profile on Photoshop, to create this cherry red out of the brownish red that was originally captured in original the Raw file.  The real CRI number, you can neither measure nor guess, if the manufacturer doesn’t tell you… But you can, very subjectively, evaluate if the colours are pleasing or not.
  • Recycling time, meaning, how long the capacitors take to fill, in order to allow a full discharge. The shorter, the better, as you don’t want your subject to run away, in between shots. 

Then there are other factors, like an aiming or focus light, the sturdiness, the batteries type (and recharging time), the ergonomics, and so on.  

To cut the long story short, a good strobe is, generally, one that can deliver pleasing colours, at a good shooting distance, with strong power, a wide beam, smooth transition, short recycle time, powerful focus light, good ergonomics, light, and travel friendly. Needless to say, that strobe doesn’t exist. All the existing ones are compromises, sacrificing some parameters for the sake of others. 

Backscatter Mini Flash: a flash for Macro 

For macro shooting, there are some parameters you can sacrifice, meaning:

  • Power, as you will, supposedly, shoot very close to your subject.
  • The wideness of beam: in fact, often you want a narrow beam with a visible, abrupt, transition, so you can isolate the subject from the background, or avoid backscatter.

Building a specific macro strobe should be easy.  For many years I wondered why manufacturers didn’t produce underwater strobes for macro photography. After all, shooting macro is what the vast majority of the UW photographers only do. 

Now, Backscatter is introducing the first macro dedicated strobe. It seems a dream come true, for many photographers, including me, specially because it comes with its own, dedicated, snoot.  It is not exactly a bargain (399 USD for the flash, or 499 for the combo from Backscatter in USA. Check Singaporean prices in here), but is definitely cheaper than most, if not all strobe + snoot combinations in the market. 

Backscatter Mini Flash and Snoot Combination – this is what you get in the package.

I was lucky enough to get a test sample from Divesea, and tried it on a couple of pool tests and some dives around Tulamben (Bali, Indonesia). I own a few UW strobes (Hartenberger 250 TTL, Subtronic Pro270, Sea and Sea YS-01) and had a few more models in the past. For snooting, I usually take the Subtronic, along with Retra LSD or Saga Optical snoot which is a bit like taking a 10 ton truck to the weekly grocery shopping. The combination is bulky, heavy, and those 270 watts of power are not really needed for critters of a few millimetres in size.

As for Backscatter Mini flash, here are the specs, copy / pasted from Backscatter website:

Strobe Specifications:

  • Depth Rating: 100m/330ft
  • Guide Number: ƒ16
  • Lumens: 500 Lumens
  • Power: Single 18650 Battery**
  • Recycle time (full): 2.5 seconds
  • Number of Flashes (full): Up to 1400**
  • Weight in Air: 13.25oz/375g
  • Weight in Water: 5.29oz/150g
  • Sync Cord: Fiber Optic
  • Seal: Dual O-Rings
  • Exposure Control: 
    • Flash: 6-step Power Level 
    • LED: 3-step Power Level 
  • Dimensions With Ball(LxWxD): 
    • 7.36 x 2.31 x 4.06in
    • 187 x 59 x 104mm
  • Material: Anodized Machined Aluminium
  • Included Accessories: 
    • 1-inch Ball Mount
    • YS Mount
    • Diffuser
    • Spare O-ring Set
    • O-ring Grease

Battery & Charger Not Included.

  • * Specifications are from pre-production model testing. Production specs may vary slightly.
  • ** Only use approved 18650 Battery

Snoot Specifications:

  • Compatibile Stobes: Backscatter mini Flash MF-1
  • Depth Rating: 300ft/100m
  • Weight in Air: 9.70oz/275g
  • Dimensions (LxD):
    • 7.24 x 2.56in
    • 184 x 65mm
  • Material: Anodized Machined Aluminium
  • Included Accessories:
    • Circular Aperture Card
    • Oval Aperture Card
    • Lanyard

The shooting experience:

The first thing I noticed after assembling the unit was some trouble on turning it on. The “On” button must be pressed 5 times under 3 seconds (in total). No, that’s not a cryptic treasure hunt… It’s just a way to turn it on!! Couldn’t it be 3 times, 2 maybe? Why 5? It’s beyond my understanding, and more than once I struggled with it. Once you get the time and pace correctly, it’s a no brainer.

With Snoot:

Once I got it to work, I didn’t care much about using it alone. It was the snooting that got me excited, specially the narrower beam circle. It didn’t disappoint: the focus light is pleasingly powerful.

The 8.5 cm distance from the subject (to get the sharp beam light edge) is convenient. …Far enough not to disturb it too much and near enough to allow precise aiming. 

In the pool testing, 8.5 cm was the result I got for sharper edged beam.

As it’s not that forgiving in distance  (too far reduces power dramatically and widens the beam; too narrow also widens the beam and possible burns the highlights in some areas), it’s better to have it on a fixed set-up than to have it on lock-line arms or hand held. 

A triple clamp and two carbon extendible arms from Inon was the combination which best worked for me. I tried lock-line arms but it didn’t stay still. Notice where the strobe buttons are, and where the photographer should be.

Overall, the snoot shooting experience is fairly easier and more rewarding than any other strobe / snoot combination I tried. 

Focus lights under the red arrows. Notice how Backscatter’s is brighter. The optimal distance for Backscatter is half the one from Retra and Subtronic.

I didn’t find too much difference among the two aperture cards (oval and circular) in real world shooting. Both worked and the shape can be achieved through shooting angle. 

Without Snoot:

It is certainly possible to UW macro images with this strobe alone, and the gallery is there to prove it. However, I have to admit this certainly wasn’t the easiest strobe I ever tried to make work. It simply doesn’t have enough power or diffusion for most fish portraits or Close Focus Wide Angle sceneries. (Its 16 guide number, announced, is far inferior to 20 of the smaller and portable Sea and Sea YS-01; and that translates into a not-so-smooth shooting experience.)

I picked a 60mm macro lens, to reduce distance to subject as much as possible. The problem is that, shooting that close, a minor shift in distance causes the image either to be underexposed or blown in the highlights. On fast moving critters it’s too challenging. Besides, in most, if not all, situations, I had it on full power, so having only one shot at a moving critter (due to the 2.5 second recycle time) narrows the chance of success. The diffuser didn’t help. In fact, there is more change of light (power and diffusion) on a 5 cm shift of strobe position, than on using (or not) the diffuser. 

Colour temperature is not announced (I estimate it around 4800K, but don’t take this value too seriously). I can see a smoke filter in front of the flash bulb, probably to warm its tone. There is certainly room for improvement, regarding light “quality”. Photoshop can do wonders (and it’s widely used on all the gallery shots), but the colours, usually don’t pop right out of camera. 

The strong points:

  • Focus light: the announced 500 lumen twin led light are more than enough for snooting, even at shallow depths under broad daylight. There are 3 levels and I found myself often shooting at the lowest. 
  • Size and weight: 375g for the flash, is definitely better than the 950g of the Subtronic 270 Pro (not including battery), and being slightly negative (150g) helps when you hand hold it or have to lay it on the ground. It’s easy to hold, like a torch.
  • Power with snoot: shooting at ISO 64 and the narrowest apertures (F/32) at optimal distance, I often had to lower the power one or two steps (depending on subject) to get optimal exposure. Couldn’t ask for more.
  • Battery: I prefer a single 18650 battery to bunch of AA ones. There are less things to go wrong, regarding battery failures and it makes the unit smaller.  1400 flashes at full power is outstanding, though I didn’t have the chance to test it. 
  • Exposure control: The 6 steps dial makes it easy to match exposure if using a dual strobe combination. Bravo!  
  • Price: While the strobe alone isn’t exactly cheap, the strobe + optical snoot combination, is the cheapest one I know.
Two strobe and snoot combinations, firing simultaneously at the narrowest aperture and full power. (I/320, F/32, ISO 64. Shadows were pulled in Photoshop) On the left is Backscatter Mini Flash with snoot. On the right, Subtronic Pro 270, with Saga Optical Snoot. Backscatter Mini Flash is far more powerful, getting a smaller light circle. Photoshop requires roughly +4 in exposure so the Subrtonic/Saga matches Backscatter. With Retra and Subtronic, the difference is less but still +2.5.

The improvements to make:

  • Focus light:  it would be nice to have a red light option and / or a weaker one. I found most critters (even nudibranchs) not to be too fond of it, something that doesn’t happen that much with the Retra + Subtronic combination).  Focus light goes off and then dim, for maybe 2 seconds after shooting regardless of power level selection. Basically it means that you cannot take advantage of a shorter recycle time on the lower settings, as you won’t be able to see the critter and refocus / shoot before those two seconds. It’s really annoying and I believe it’s absolutely not necessary. Please, change the firmware and have it go off for the milliseconds the flash fires. 
  • Shape: Backscatter made a strobe and snoot combination that is only 2 cm (ish) shorter that Subtronic Pro 270 plus Retra LSD which are one of the biggest strobes and snoots on the market! Why didn’t they designed the battery on one of the sides, instead of behind the whole flash unit? Fully assembled on a DSLR rig it is hard to carry, and prone to shaking under currents or surge, if you don’t use sturdy arms. I cannot imagine it on a compact rig… Backscatter took a very questionable option on design (using the battery encasing from an existing torch instead of designing a new one?). The shape itself translates into the following issue, which is:
  • Ergonomics: The buttons are placed opposite to the fixation point. In this flash current shape, there is probably no other place where they can be. The problem is, as the arm that holds it is coming from the housing (thus, facing the photographer) the buttons will face the opposite, i.e., the ocean in front. I couldn’t see the dial and button most of time, and had to swim around the housing to check it, when needed. I don’t particularly fancy the “On” button. It’s common to many Chinese UW torches (Divepro / Jaunt / Scubalamp, just to name a few) and I had already two failures with those. The colour light power indicator, often cannot be seen and I cannot believe the 5 press turn on and off is something really needed. 
  • Accessories: The diffuser is positively buoyant, meaning, if you let it go when detaching it (to put the snoot, for instance) it will float to surface. It’s just a plastic cap, which doesn’t do much to really diffuse the small bulb emitted light. It should be redesigned, probably made on acrylic, so it can properly spread the light beam.  Both it and the snoot shaping accessories have thin black cables, that often get entangled. They don’t look too strong, as well, and I can foresee them breaking loose. The oval aperture cards are too similar to each other. I’d prefer a narrow ellipse and / or some creative shapes, like Retra. I also prefer the Saga Optical snoot disk, than the Retra style cards, but that’s just me. 
  • Recycling time: Knowing that recycle time depends on battery and capacitor size, (and so it’s physically impossible to have a powerful, small strobe, with fast recycling) I still believe the 2.5 seconds announced, are not overly ambitious, for such a small powered unit. 
  • Pre-strobe TTL cut: this is a manual-only strobe, and I have no problem with that. However, some compact camera shooters may not be able to use it. Some cameras don’t have manual strobe option (they only shoot some sort of TTL, with one, or a few pre-flashes before the exposing flash). Different from Sea and Sea and Inon, this model doesn’t sync with those cameras, as there is no option to avoid firing on the pre-flashes.  
  • Written information: I didn’t find the Kelvin Number for the flash light, with and without the diffuser and that is sort of important, for correctly setting the white balance.
Nearly 2 cm is the difference in length of the two setups. It doesn’t make that much sense, considering the differences on raw power.

Overall feelings and conclusions:

I certainly welcome Backscatter into the UW strobe business. This product fills a niche in the UW strobe market and can produce beautiful images as it is.

The concept is great: a mini version of Retra, that can be used specifically for macro, cheaper, more portable and easier to carry. 

Unfortunately, if falls short (mostly of power, I mean) when used alone (with no snoot), so that certainly wouldn’t be the only strobe I would take for a macro shooting vacation. …But I would add one to my macro setup, to make snooting easier and increase my speed of shooting and keeper rate.  So far, it’s a definitely good product that could easily turn into a great one.

I hope Backscatter keeps this trail and does a version 2 of Backscatter Mini Fash and Snoot, with added experience, with different (more compact) shape, slightly more power, a different diffuser (or the set of bulb and diffuser), a simpler button, red focus light, visible dials and more accessory options.

Nikon D810, NIkon 105 Micro VR 2.8, AOI UCL-900, 1/250, F/32, ISO 64
Bornella sp. juvenile nudibranch.