Float for Backscatter Atom Strobe

Add 140 grams buoyancy!

The Backscatter Atom strobe is great strobes for underwater photography. Small, light, and versatile. Its biggest drawback is how much it weighs in water. The Atom is 150 grams (5.3 oz) negative in water with batteries.

This 3D printed float will add 140 grams of buoyancy leaving it just 10 grams negative. (0.35 oz) You don't want to have the strobe be positively buoyant. Slightly negative is easier to handle and balance the overall system.

Balancing your rig is important. If you need to add additional buoyancy to your camera rig, I suggest using float arms or Stix jumbo floats on the arm segment closest to your housing. Leave the second arm connected to the Atom strobe without additional buoyancy.

Attach Float to the Atom:
The float has anchor points that will allow you to thread 1/8 inch (3 mm) bungee cord. Many divers keep 1/8 bungee on hand as it is so useful. It can be bought in bulk online or at any dive shop. Tie a simple overhand knot at each end of the bungee to keep it from slipping thru the anchor. It should be just slightly taught with plenty of elasticity to pull over the strobe and keep it snug.

Note before printing: This is a technical and exacting print. It requires very specific and exact filament and printing parameters. If you ignore or change the defined print profile and settings it is very likely that your float will not work.

[And YES - You can make watertight and pressure resistant 3D printed objects with no added sealants or post processing!]

This is very cool solution. But I do wonder why UW camera manufacturers make very compact and very dense equipment, I get the point of staying small and travel‑friendly. But I realized once you add all the floats needed to make the rig neutrally buoyant, the system ends up being nearly the same size as a mirrorless kit (say if you’re coming from a compact camera setup). At that point, the advantage of going compact feels lost — you might as well start with bulkier gear that’s already close to neutral in the water.

20 minutes ago, Pomacentridae said:

This is very cool solution. But I do wonder why UW camera manufacturers make very compact and very dense equipment, I get the point of staying small and travel‑friendly. But I realized once you add all the floats needed to make the rig neutrally buoyant, the system ends up being nearly the same size as a mirrorless kit (say if you’re coming from a compact camera setup). At that point, the advantage of going compact feels lost — you might as well start with bulkier gear that’s already close to neutral in the water.

I think you are correct, in general.

However, the Retra Maxi strobe is actually bulkier than their past strobes and than similar HF-1. That size and displacement leaves it just a few grams negative in the water. It seems to me they optimized for a buoyancy target more than minimum size of the package.

7 hours ago, Pomacentridae said:

This is very cool solution. But I do wonder why UW camera manufacturers make very compact and very dense equipment, I get the point of staying small and travel‑friendly. But I realized once you add all the floats needed to make the rig neutrally buoyant, the system ends up being nearly the same size as a mirrorless kit (say if you’re coming from a compact camera setup). At that point, the advantage of going compact feels lost — you might as well start with bulkier gear that’s already close to neutral in the water.

Bigger housings are not buoyant as well therefore in the end, you also end up adding more floats to them than what you add on a smaller camera.

23 minutes ago, eocean-eu said:

Bigger housings are not buoyant as well therefore in the end, you also end up adding more floats to them than what you add on a smaller camera.

Larger housings actually are generally more buoyant than smaller housings. With Retra Maxi strobes on my NA-6400 (or NA-R50) I need to tie a string on the rig and pull it around like a helium balloon at the fair. I am going to have to remove some floatation or add lead. That is with a 4.33 dome, with the WWL it is a few ounces negative still and either way balance is perfect. I do not know if it was engineering expertise or just luck but the Retra Maxi strobes are perfect in the water, neutral, sometimes bigger is more littler.

The price Delta between the HF-1 and the Retra Maxi is not huge, with floats on the HF-1 it is larger than the Maxi. But if I had an HF-1, I think I would want a set of those floats, looks like a great solution to a boat anchor of a strobe and they look professional and I bet they can be gotten in blue!

Edited 4 hours ago4 hr by Nemrod

31 minutes ago, Nemrod said:

Larger housings actually are generally more buoyant than smaller housings. With Retra Maxi strobes on my NA-6400 (or NA-R50) I need to tie a string on the rig and pull it around like a helium balloon at the fair. I am going to have to remove some floatation or add lead. That is with a 4.33 dome, with the WWL it is a few ounces negative still and either way balance is perfect. I do not know if it was engineering expertise or just luck but the Retra Maxi strobes are perfect in the water, neutral, sometimes bigger is more littler.

The price Delta between the HF-1 and the Retra Maxi is not huge, with floats on the HF-1 it is larger than the Maxi. But if I had an HF-1, I think I would want a set of those floats, looks like a great solution to a boat anchor of a strobe and they look professional and I bet they can be gotten in blue!

Blue or even Red!

The HF-1 w/float is a bit bigger than the Retra, but not by a lot. Max diameter is about 15mm more, height and weight are nearly the same as the Retra's are heavier to start with.

When I first put the Retra Maxi's on my Rig, replacing the HF-1s, it was annoyingly buoyant and unbalanced. I had to remove 2 Stix Jumbo blocks (180grams each) to get it back in some sort of decent trim. The HF-1 floats are a bit more buoyant the Stix Jumbo at 220 grams each. Using the HF-1 floats now is actually a big convenience because I don't need to Add/Remove Stix blocks on my arms when I switch between Retra and HF-1 strobes.

Edited 4 hours ago4 hr by Dave_Hicks