How positively buoyant are the seafrogs housings?

there are too many variables for a useful answer here without someone using the seafrog with a compact mirorrless and the same strobe arm arrangement as you.

generally speaking, the compact housings with cameras inside are negative, and more so when you add on the strobes.   That's why there are so many float and fat strobe arm options, and float rings for the macro port.   These rigs are commonly paired with a fisheye and a 4" dome for wide angle, which doesn't make up for the weight.

That said, if a manufacturer uses a larger plastic shell to cover a wide range of models, rather than bespoke molds with little dead space, they will be lighter.   And if that goes to an extreme, the weight of the strobe/arms isn't enough by itself as it creates a rig that wants to turtle.  Ideally you want to screw in ballast to the bottom of the housing to encourage the upright position.

But I'd be surprised if this is actually needed for the M50.

My M4/3 system (GH4) required a lot of floatation.   My SLR one (R5) needed virtually none - one float at the top of the strobes to stop the pivot.  I think I could do it by just making neoprene covers for the strobes, which would be good for them anyhow.  But there is a lot of experimentation to do and it applies to every lens config.     Salinity variation means you won't be dead on, but that is a tiny amount.   Ideally, IMO, you're ever slightly positive so that for macro, you're pushing/pulling it down to steady, rather than having to apply a continuous lifting force.  The latter results in a sore elbow after the dive, and false DCS fears.

One advantage to negative that occasionally comes up is the ability to put the rig down briefly.  Once in a bull moon I've done this.   I think there are more cases for it being floaty, most notably when your coil breaks during a deco stop in Truk Lagoon over a 300' sand bottom.  (don't trust plastic coil systems to last forever - they will eventually fail)

Thanks. My limited experience has also been with slightly negatively buoyant rigs and that feels very natural. Sea frogs does specifically highlight their cases are “very positive” (their words) and I get the impression some of the cost savings on those housings are from not engineering them to fit too precisely, leaving a little extra air especially with a dome. I’ve also seen two video reviews which mention the rigs float more than others.

Sounds to me that adding strobes and handles etc is going to counteract this enough to get close to neutral and I would definitely be adding those so I think I don’t need to worry too much.

Thanks. That kind of real world experience helps a lot. Let me go find some heavy strobes!

What lens or lenses do you plan on using?

As you no doubt know, the M50 body is really light. The native M lenses are also really light.

The image is not mine, but I ran across this image while looking at housings.  It should give you a scale of how much bigger the Seafrogs housing is than the M50.

I'm looking seriously at housings right now and tempted to get one for the M50ii I already own.  My biggest concern is battery life, which is pretty terrible.  With these housings in slat water, you don't just pop it open to swap out a battery.  For that reason and the smaller buffer, the M6ii housing is looking better.

Not sure if this helps much, but I recently picked up a Seafrogs housing for a camera I don't own, the full frame 6D ii.  It was too cheap to pass up.  I made a stack of washers equivalent to the weight of a 6D ii and the 24-105L ii (a pretty heavy lens).  I took it to the bathtub and then a swimming pool to see if could get the buoyancy right.  The camera and lens are supposed to weigh a kilo and a half.  It took another 500 grams of weight to get it neutrally buoyant.

If you don't have the EF-M 32mm lens, you should really get one.  It's amazing!

wlderdude wrote:

As you no doubt know, the M50 body is really light. The native M lenses are also really light.

Interesting.   The Panasonic GH4 is quite dense, but I can see how a plastic body could go the other way.

I'm looking seriously at housings right now and tempted to get one for the M50ii I already own. My biggest concern is battery life, which is pretty terrible. With these housings in slat water, you don't just pop it open to swap out a battery. For that reason and the smaller buffer, the M6ii housing is looking better.

?    With any non SLR, changing batteries every other dive is pretty normal, and some will do it on every.   Not ideal, and unlike the flash card, it's normal to have to pull the camera out slightly to reach the battery.

Not sure if this helps much, but I recently picked up a Seafrogs housing for a camera I don't own, the full frame 6D ii. It was too cheap to pass up. I made a stack of washers equivalent to the weight of a 6D ii and the 24-105L ii (a pretty heavy lens). I took it to the bathtub and then a swimming pool to see if could get the buoyancy right. The camera and lens are supposed to weigh a kilo and a half. It took another 500 grams of weight to get it neutrally buoyant.

The strobe arms are usually pretty good for this, though working on the trim could be tricky if the housing base is positive.   That would give it an innate tendency to want to invert.