Camera Bouyancy

[geokr]

I'm new to underwater videography and would appreciate any advice or points in the right direction on determining the right amount of camera/housing bouyancy for underwater work. I recently purchased an Equinox HD6 housing for the Sony SR12 and am going on my "shakedown cruise" with it to Cozumel in May. I'd like to get anyone's thoughts on how much weight to put in the housing for videos that will be shot hand held. Should I try to find "neutral" or is some negative bouyancy good for stability? Again - total novice here so any and all suggestions or references will be most appreciated. My search on the site only came up with photography suggestions and video, as you know, is quite different.

Thanks.

 

[Mr.X]

I prefer the package slightly negative. It allows me to hold my shots better. The downside is that it no longer wants to bob up to the surface.

If you're going to add lights you need to consider that as an aspect of the buoyancy package. I've used housings which (without arms and lights) were almost perfectly neutral and balanced. Once, you added the arms and lights it became something entirely different.

If possible, I would take the housing and camera to a local pool and give it a shot. See how it works for you. Once you buoyancy worked out in a benign environment you can add the % difference when you reach your salt water destination. As per weight I've used a variety of ballast ranging from slivers of lead, small packets of lead shot etc.

X

 

[geokr]

Thanks - that opens up a whole new set of challenges to overcome, doesn't it? With a slightly negative object held out in front of me my center of bouyancy (or balance) is going to change as well. I've got a lot to adjust to, don't I? Well, if it was easy everybody would be doing it.....

Do you use a lanyard to keep it attached to you?

 

[ronscuba]

Thanks - that opens up a whole new set of challenges to overcome, doesn't it? With a slightly negative object held out in front of me my center of bouyancy (or balance) is going to change as well. I've got a lot to adjust to, don't I? Well, if it was easy everybody would be doing it.....

Do you use a lanyard to keep it attached to you?

Good observations. Does your housing have a monitor or is your mask pressed up on an eyepiece ? It can make a difference on whether a neutral or negative is housing is preferred.

My old housing did not have a monitor, so shooting position was limited to up against my mask. In this position, I preferred a neutral housing for the reasons you mentioned.

My current housing has a monitor that tilts. I can pretty much film in any position I want. But for super steady shots, I prefer the housing negative, held below me with the monitor tilted up.

 

[diversteve]

I like it a little negative. I find it helps with panning. Very occasionally I've found myself in a position where I want to set it down on the sand to film something like yellowhead jawfish so I like it to stay put while I back off.

I use a Cetacea lanyard with a locking caribiner attached to it. Has a brass bolt snap on the other end to clip to my BC. Similar to this one except I removed the loop at the bottom and threaded the caribiner through it. Cetacea Corporation - Scuba :: Coil Lanyards :: Coil-Lanyard w/Brass Snap

With your housing, you'll never want to splash with it. Have someone hand it down.

 

[geokr]

Pretty easy to see I got a lot to learn. My next trip is going to be an "eye opener". My plan on the first dive is to take the empty housing down to a hundred feet to make sure it doesn't leak then try some shallower dives to get the feel of the controls, experiment with zoom and stills and depth of field, all in natural light. The next big investment will be lighting but not until I have gotten familiar with the camera and housing in "what you see is what you get" conditions. This housing has manual controls and after trying them out I wish I had bought electronic ones. Very awkward to use. But, that's part of the learning curve. Thanks to all for your very sage advice.

 

[mobula]

The negative or positive buoyancy is one point. Beside a slightly negative buoyancy there is one thing to think about: does the housing flip? A monitor on top is maybe one reason or if the weight is located in the back of the housing. Sometimes the lens pulls the housing down at the front. The worst combination to me is if the front pulls upwards and it is positive at the same time. One of my housings needs 1,8 kg in front to make it neutral and well balanced.

 

[geokr]

The negative or positive bouyancy is one point. Besdie a slightly negative buyancy there is one thing to think about: does the housing flip? A monitor on top is maybe one reason or if the weight is located in the back of the housing. Sometime the lens pulls the housing down at the front. The worst combination to me is if the front pulls upwards and it is positive at the same time. One of my housings needs 1,8 kg in front to make it neutral and well balanced.

Hadn't really thought about that but agree that I will have to experiment with matching the centers of gravity and bouyancy. It's too cold to go in the water here - maybe I beed to fill the bathtub and see how it reacts!

 

[mobula]

Maybe try it in the pool, indoor. I did this week to show a guy how on of my housings work. For my Sealux housing I advised the manufacturer to develop a weight system. The problem is often a safe and easy attachment of weights. Good buoyancy will help you to keep the housing steady.

Two more advises:

1) Use a wideangle and avoid zooming, you will have much clearer pictures
2) Use the focus. Dependant of the light situation and the distance some pumping of the ffocus could appear which you don't see underwater on the screen. With a 90° wideangle 0,8 mostly works fine. Or point to you fins and fix the focus.

 

[geokr]

1) Use a wideangle and avoid zooming, you will have much clearer pictures
2) Use the focus. Dependant of the light situation and the distance some pumping of the ffocus could appear which you don't see underwater on the screen. With a 90Ž° wideangle 0,8 mostly works fine. Or point to you fins and fix the focus.

Got the wide angle lens. No focus control on the housing so I'm not sure that I can change focus unless, like my old camcorder, you can fix it at infinity - will check the manual for the SR12.