View Full Version : homemade u/w case?


Brian-John Alford
March 20th, 2004, 11:45 AM
Hi all,

Im making a documentary this summer in Papua New Guinea. All been funded for by Oxford Uni. It's just I don't have any method of taking my xl1s underwater - the documentary is following a team of coral reef surveys and conservation work.

I can't afford the hard cases and as the dives will be around 15-20m the soft cases are of no use.

I was wondering whether it would be possible to build one. Surely, all that will be needed is a plastic tube and put two clear plastic windows..one at each end and then sort something out for the lens connection.

If anyone has any experience or tips they would be very kind.

Dean Sensui
March 21st, 2004, 03:34 AM
I've done some UW video work and can say definitively that you'll need a well-made case.

At two atmospheres it takes just a hairline gap to cause a flood. If you get a little grit or a hair in the o-ring seal, the housing might stay dry during descent. But once the pressure reaches a critical point, it'll take on water amazingly quickly.

I would suggest getting an Ikelite case and another camera. Ikelites work amazingly well particularly if you have a dome port for the wide lens... and you're going to need a wide lens to move in close and get clear shots underwater.

If you need a 3-chip camera then consider a GL2. If a 1-chip would work, then there are housings for other Canon and Sony cameras. Keep your XL1s out of the water, unless you have a backup, especially in someplace like New Guinea where there may not be suitable emergency service available.

I worked with both a commercially made housing from Ikelite and also made one with the aid of a machine shop. It is possible to build your own using a thick PVC pipe for the housing and 1" thick plexiglass for the end pieces. I also fitted a dome port for the wide angle lens.

The thru-fittings were from Ikelite and that provided the camera controls.

Being a cylindrical housing, the diameter ended up being significant due to the size of the camera used: a Sony Betamovie. There's a lot of wasted space in something like that and the added air space translates into more ballast to attain neutral buoyancy. It ended up being about 65 pounds!!

Maybe you can talk the folks at Oxford to assist in building a housing? If you do build one then here's what you'll need to consider for basic controls:

-- Camera controls: Power on/off (possibly optional considering how long the batteries last).

-- Tape start/stop.

-- Focus. Have something set up that will allow you to hit the "autofocus" button. You could also set up a gear-driven focus setting. Or you can pre-focus the camera prior to the start of the dive. Take note that a dome port changes the optics and "infinity" is now a spot 2 feet from the focal plane.

-- Viewfinder -- maybe a small LCD monitor.

-- Zoom. Optional, unless you plan to shoot tight close-ups. Depending on the clarity of the water you'll want to get as close to the action as possible and that means using as wide a lens as possible. The standard lens isn't wide enough so consider getting a wide angle adapter or using the 3x Canon zoom. Speaking of which, the 3x Canon zoom is shorter than the stock 16x lens and takes up less volume. That translates into a smaller housing and less ballast.

Personally, I'm hoping that Ikelite makes a housing for Canon's latest Eluras with the 16:9 chips.

Hope this helps. And good luck on the documentary!

Dean Sensui
Base Two Productions

Rick Bravo
March 22nd, 2004, 11:09 AM
Papua...damn...nice gig!

I would never even dream of putting an XL-1s or any camera for that matter, in a home made housing, unless I was the one who engineered it and knew what the hell I was doing, which I don't!

If the people that build it for you don't know EXACTLY what they are doing, you are setting yourself up for disaster.

Every thru-fitting that Dean mentioned is another place for a catastrophic failure if the proper seals are not installed. Remember that these have to maintain their water-proof integrity under pressure and while being manipulated underwater.

Two atmospheres is 66 feet, you don't have to go that deep to have a problem, especially if one of the seals goes.

Ikelite does not make a housing for the XL.

Gates does. http://www.gateshousings.com/XL1-XL1s.html

It is also the housing featured on the official Canon site. http://www.canondv.com/xl1s/tpa_gates1.html

The down side...about $4,700!

We have Gates Housings for the Panasonic AG-EZ30 and the SONY TRV-950 and they are phenomenal.

Good luck and have a good time!

RB

Dylan Couper
March 22nd, 2004, 06:04 PM
Brian-John
I have one word for you:

RENT!

This is the perfect item for a rental. You'll probably only use it once. It will cost a fraction of the purchase cost, and you won't have the fear of having a crushed drowned camera if you make your own. ;)

Dean Sensui
March 22nd, 2004, 06:15 PM
Renting is a great idea. Make sure you get insurance for the equipment and test it thoroughly before heading off on the trip.

Here's a horror story:

A highly skilled and experienced u/w cameraman was doing a series of underwater stories for a local TV station's newscasts back in the 1980's. The camera was a Betacam camcorder in a custom housing that featured a compensator to adjust the internal pressure based on depth.

At 60 feet he started to descend, following a school of fish going over a dropoff.

Then the housing imploded. $10,000 housing. $50,000 camera. No one's quite sure why it had a catastrophic failure but everyone was certain of the results... !

The rest of the stories had to be finished on 16mm film. Luckily he had that option.

Dean Sensui
Base Two Productions

Brian-John Alford
March 22nd, 2004, 06:16 PM
Thanks all for you advice. I'm a student and although I have some money not enough to purchase a gates hard case. I am going to be away for 8 weeks and Ive looked into renting and they want an obscene amount for the whole summer. Also not many people have cases in UK for the XL.

I know the real solution is to rent or buy but since unless I can get the camera underwater I may be chucked off the expedition. I can't afford a second smaller camera at the moment. When I finally leave uni(in a year) I will get the right kit of course.

I was just hoping I could build/get built by some mechanics an overly safe case. I am sure the tube to hold it wold be no problem, just the see-through ends. Could I secure them from both sides using several o rings to make doubly sure? I understand what you are saying but am I being totally unrealistic? I am not to bother by looks or size really just anything to get this documentary done! Thanks for yuor patience and future advice.

BJ

Dean Sensui
March 22nd, 2004, 07:08 PM
Hi Brian...

There are certain components you'll need and can't do without when building a housing. I was able to scavenge mine from a used housing and avoided the cost.

Some of those include: Thru-fittings for basic controls. Ikelite has these available. Spring-loaded snaps to lock the housing shut. Dome port to allow you to use a wide angle lens without the edges of the image going out of focus.

The tube can be made from 1/2" thick PVC pipe (about 13 mm). Get a pipe that fits as closely to the camera as possible. The smaller the housing the lower the overall weight required to make the housing neutrally buoyant. Every cubic foot of total volume equals about 64 pounds.

The faces of the housing would have to be 1" (26 mm) thick plexiglass (perspex). These faces have to fit the pipe with tight tolerances. That would require a lathe with quite a bit of swing to accomodate the diameter of the end piece. And the inner edge of the pipe would have to be mortised to accomodate the o-ring.

Use only a single o-ring for each opening. Using multiple o-rings may not help and might actually cause a problem as one might prevent the other from seating properly.

The faces are held in place with four clasps on each end. And the clasps are linked longitudinally from one end of the housing to the other with stainless steel straps about 1/8" thick. The straps are secured to the housing with short screws which means you'll need to drill the housing and attach the straps with stainless thru-bolts sealed with o-rings. Any drilling needs to be done with a drill press. Don't drill anything by hand as it's not accurate enough. If you don't have any experience in doing machine work, then have a charitable machinist help you out.

The camera needs to be carefully fitted to ensure the lens aligns with the dome port. Using a layout table is almost essential to get this done right. The camera is fitted onto a sled, and the sled is mounted into the housing. After you establish the position of the sled and camera you can determine the location of the dome port. The opening for the dome port will have to be cut with a lathe.

Each thru-fitting needs to be carefully positioned to ensure it meets the controls precisely. Realize that with a change in pressure there is a slight variation in the housings dimensions so controls need to be placed to avoid having the control shafts from applying pressure to the camera and still reach the desired button or switch.

Also, the control shafts themselves are being pushed into the camera housing by the surrounding water, so make certain they're set up properly to prevent them from getting shoved all the way in and flooding the housing.

You'll need a viewfinder as the camera's viewfinder will be useless. Get a small LCD screen for this.

As you can see, this adds up to a lot of specialized work and quite a bit of cost. Not to mention risk. You might be better off getting a Canon ZR-series camcorder (about $500) and a housing from B&H which might be about $700. Total, USD $1200. Not bad, all things considered.

Dean Sensui
Base Two Productions

Rob Lohman
March 24th, 2004, 02:31 AM
Ask yourself this: is it a problem if my housing implodes or my
camera drowns? I'd say it is. Especially since you are a student.
I doubt any insurance would work with a homebuilt underwater
housing. Can you afford to loose $4000+? Do you have the time
and knowledge to build such a device AND TEST IT PROPERLY?

You also need to route controls to the outside if you want to be
able to operate your camera while underwater.

Might it be possible to rent at the location you are going to instead
of in the UK?