reverse periscope

hey everybody ...

i have a question, which seems difficult to answer, since even an extensive search in the internet has brought me no closer ... maybe you guys can help me ...

i'm a finswimming trainer, training (amongst others) the current british champion and record holder in this wonderful sport (who also happens to be my daughter) on the beautiful island of tenerife ... to improve the finswimming technique of my athletes, i'd like to include underwater videography to our training methods ... this confronts me with several problems though ...

1. we have no scuba divers at hand, who could jump in the pool on a regular basis, to tape our kids ...
   
2. we have no underwater filming equipment and would probably find underwater video cameras too expensive ...
   

quite some time ago i saw a documentary though, where a swimming team used a clever gadget, to take shots of their athletes at training ... it looked like a reverse periscope, with the (economic) photo/video camera attached to the top end and the bottom end submerged into the water to film the swimmers ... this would suit our purpose perfectly ... nobody would have to actually get into the water to use the cam and i reckon, that an apparatus like this would be cheaper than an underwater camera ... we wouldn't need fantastic quality ... we don't want to win any prizes, just improve our finswimming technique ...

does anybody know, if such gadgets are available and where? ... i've looked up and down the internet and couldn't find a thing ... thx a bunch in advance, for any answer ...

greez ... jens ...

There are remote underwater video systems available cheaply. Try these for a couple of examples

http://www.image-acquire.com/aqua-cam-unde...fishing-camera/

http://www.getfishtv.com/store/?cat=FishTV

Colin

Yes, failing that there are a number of used housings for the older compact cameras that no one really wants any more. Its just a matter of finding a camera with adequate video mode and housing that matches.

Ebay is likely your friend.

Some people have made Pole Cams for shooting sharks etc from the boat. At their simplest, just a camera mounted on a pole with some sort of cable to actuate the shutter.

I think the issue with a periscope is that it would need some lenses in it, otherwise the underwater window would need to be huge. Think about the cone of light that enters the camera lens, the further from the camera, the bigger it becomes.

I'm working on something similar now for photographing skittish fish in fresh water, with a frame to hold a compact underwater camera and a cable release. I have the basic system designed in a couple of different ways, but I have run into a problem with the mirror (to reflect the LCD image up for composition). My pariscopes are designed to be about four feet long, and at that distance, the image reflected in the mirror at the bottom is too small. Plan to try a magnifying mirror, but believe some type of lens will also have to be installed at the top. It's not as simple as I originally imagined.

looks like it's gonna be more complicated, then i thought ... a reverse periscope is obviously not practical (for the reasons mentioned above) ... i'll probably have to go with a pole camera (since i don't want to get in the water every time we need a video) ... i wonder, if i can find one cheap for one of the three cams we have in the family ... i'll follow balrog's advise and have a look at ebay ...

also interesting are the underwater tv systems colinrobson posted ... they have the advantage, that one can see straight away what is being filmed ... with the pole cameras i foresee the problem that half of the shots can't be used, because the swimmer is not properly framed ...

thanks every so much for all your replies ... you guys were a great help! ...

greez ... jens ...