MDX RX100M/2 Housing Bouyancy

[dmoore19]

I bought the Sea & Sea housing for my Sony RX100 and a YD-D1 strobe. I want to be able to get this neutral bouyant. It would seem to me that the bouyancy requirements would be fairly standard. Is this information published someplace? If so I have been able to find it.

Does anybody have any idea where to start? Yes, I know you can hang it from a scale to determine it's weight. Seems like a bit of work that doesn't really need to be done. Any ideas of where to start?

 

[Larry C]

Buoyancy will vary depending on ports and lenses. I don't know of any buoyancy guide. Take it diving, let go. If it rises, have a variety of small weights along. If it sinks, you'll need to add buoyancy floats. Personally, I don't care much about perfect neutrality. My rig is a stone, even with two buoyancy arms and a float on the focus light. OTOH, if I put my fisheye dome and 17mm extender on, it not only floats but flips port upward as well. That drove me crazy. Not an issue lately since I've gone to a smaller dome, but the solution was to be stick-on wheel weights on the shade ring of the dome. There is no easy answer except if you find someone with the exact same set-up you have.

 

[dmoore19]

Thanks,
There is a wide angle lens that I could get but I don't have that right now.
I finally looked hard enough and the info is available.

Looks like it will be about 31.72 oz wt underwater. I can at least start with those numbers. A couple of pounds of lift will probably make things just about right!


Strobe YS-D1
[Weight] : 610g / 21.5oz (w/o batteries) * Attached a YS Mount
Strobe Adaptor and a fixing bolt to the Strobe.
[Underwater weight] : Approx.+0.5g / 0.02oz(w/ batteries)

Housing MDX RX100MII
[Weight] Approx. 800g / 28.0oz (housing only)
[Underwater weight] Approx.900g / 31.7oz (including the camera)

 

[Larry C]

Stix floats will give you 13.5oz for a set of four. ULCS large buoyancy arms will give you 4.5oz each for 8" arms. With a single strobe, you may find your rig out of balance. Another solution I've seen is home-made floats from a length of capped PVC pipe running across the top of the tray handles, between the two. I've also found that a buoyant rig is worse than a negative one, as when you tie it off to do other tasks it floats in your face.

 

[dmoore19]

Stix floats will give you 13.5oz for a set of four. ULCS large buoyancy arms will give you 4.5oz each for 8" arms. With a single strobe, you may find your rig out of balance. Another solution I've seen is home-made floats from a length of capped PVC pipe running across the top of the tray handles, between the two. I've also found that a buoyant rig is worse than a negative one, as when you tie it off to do other tasks it floats in your face.

I have a tray for it. It has lockline arms, one on each side with GoBe 700's. The housing and the strobe sit between the locline arms. I also mount a GOPro on the cold shoe on top of the housing. I saw the STix floats but don't know if they will fit over the locline, it is 3/4" locline. I would more than likely put the STix on the locline arms and add them to the arm for the strobe as well to balance things out a bit. It looks like that will take 2 of the jumbo sets of them, or 1 jumbo and one regular sized set.