Rig Buoyancy and trim - spilt from "DSLR/n interesting&

:roll:

The one thing that never ceases to amaze me is the topics that people will argue on the internet over. Some people like negative. Some like positive. Get over it.

For the record, slightly negative for me. I will be interested to see where the A300 with ULCS and dual YS90-DXs falls in this spectrum, both with the macro port and the dome.

Chris

Hi Chris,

Let us know as soon as you get out of the bathtub, ok? I told you it's not safe to type on your laptop from the tub!

Cheers

James

LOL, well, ya got me on that one.......

That's why I like a negative rig, not far to fall to the porcelain...... 8)

I don't think anyone is arguing about positive versus negative rigs. No one here has expressed a preference for a positive rig although I know some who do.

Thanks, George. It's not that a camera weighs a pound or two that matters, it's adding a pound or two to a rig that already weighs that much that's the problem. Those are realistic concerns with a three pound body.

Tom himself referred to being on a soapbox. A soapbox is "a platform raised above the surrounding level to give prominence to the person on it" and being on one means "speaking one's views passionately or self-importantly". Clearly Tom needed to refute my point with passion and authority even though he didn't seem to understand it or give any consideration to it. Even at that, I posted three times with what I consider to be tempered responses. My original comment was:

It costs half as much and weighs a pound less. The weight is a serious concern as anyone housing a 1Ds can tell you. I expect the Kodak to [be] easier to balance underwater than any pro body although that's subjective.

Would anyone seriously refute this (typo excluded)? Even if you don't believe it's important would you "get on your soapbox" to disagree? Would you suggest that people who couldn't handle the extra weight shoot a digicam instead or loose a few pounds off their gut? Tom felt strongly enough about this point that he mentioned that he had to laugh every time he heard it, yet when he "quoted" me he changed my words and my meaning entirely. I never said a 1Ds was too heavy, I said the 1Ds was heavy when housing it. Big difference. People who think I'm being a d**k should go back a reread the thread. If I criticise someone's remark at least I have the respect to understand them and I don't misquote them. I have no anti-Canon or anti-1Ds bent though I don't think others are quite so objective.

I never said a neutral housing was important to everyone but simply that the Kodak was easier to make neutral and that was an big advantage underwater. I know of no one who prefers an extremely heavy rig underwater even if many prefer a slightly negative one.

Craig, I took your comment for exactly the way it is worded, that the 1 lb difference was a serious concern to anyone. Maybe I misunderstood what you said, if so, then so be it.

Not that I feel like I have to explain myself, but when I made the soapbox comment I was referring not just to YOU making the comment about the weight of the 1D series, but that statement in general, including those that make the statement about it for topside use. I do laugh when I hear it, because people make the comment and expect it to be like carrying around a massive ball and chain. The reality of the 1D versus many other digital SLRs is that yes it's bigger and weighs more, but it's not exponentially heavier.

As for people referring to you as a d**k, I think it might have had something to do with the fact that you took an OPINION that I stated and attacked me personally by calling me ignorant. Despite that, others (myself included) have tried to continue the discussion civilly.

You insist that people should read your post more carefully. Maybe you should do the same with mine because you missed a couple points, including the next to the statement about weight (indicating I was joking / making light).

So, all that said, while I stand by my opinions stated (even if they weren't entirely clear), I apologize if I offended you or misquoted you. Can we please let this go now? I'm sure everyone's tired of the drama, I know I am.

I see what you mean Craig. You said that the weight a camera for underwater use in a HOUSING (be it 1Ds, Kodak, or Nikon) is important, and I totally agree. For topside use, one pound give or take doesn't mean much. But underwater, it is VERY difficult to "make up" that pound, either using a larger volume housing (like Sea and Sea) or with added external buoyancy. A pound requires a considerable volume to displace.

Cheers

James

Man this is a great topic. Buoyancy even becomes more of an issue with myself not including the camera. I dive maybe 3 times a year and depending where I dive makes a difference as to how much weight I am wearing. In Cozumel I had on two extra pounds with the drift diving and to also make sure I didn't blow any safety stops, especially since we did some pretty advanced stuff like Maracaibo (150ft) and Punta Sur (140). I was using a total of 14 pounds. On a liveaboard I am able to get down to around 9 to 10 pounds. As I have gotten older the lead has seemed to increase, I wonder why. Now to add to the confusion I am changing camera system all together. Going from a Nik V to a D70 Ikelite housing. I just need to take longer trips and dive more, and maybe eat less...heh! I also find that if I use more weight than intended and don't have good control of buoyancy I run a greater risk of damaging coral by being more clunky on the reef (I hate that very much).

Tony

Hi!

My housing is about 100-150g negative (with lights attached). I took the empty housing for a test recently. The feeling was horrible (missing 1 kg). If I'd to choose, I'd prefer a slightly negative housing to a positive. it comes more natural to me.

What I mind most, is the torque. I managed to get the dome large enough to compensate for the extra glass so the camera keeps pointing where I aim it (rather than a friends EOS300 with WA, which drags down with the port).

What I learned to love is that the batteries underneath the housing keep it horizontal, no matter what happens. Adjusting the lights doesn't influence at all. This may be a disadvantage when doing portrait shots (which I do rarely). Although 10kg on land, it's no problem shooting single handed.

I'm now researching the possibilities to build a "tank strobe" so the main weight stays close to the center. This would allow adjusting the light without altering the buoyancy behaviour. I hope to have some results by autumn.

Helge ;-)=)

BTW, I'm going to have the Olympus E-1 housed (bought it already).

For the record, slightly negative for me. I will be interested to see where the A300 with ULCS and dual YS90-DXs falls in this spectrum, both with the macro port and the dome

What you will notice more than the negativity is the balance of the rig with the dome versus the flat port.

While I prefer my Aquatica SLR housing over my old Ikelite SLR housing, the Ikelite was better behaved with regard to balance. The case was less negative and more square. Combined with a smaller dome port the rig had a better front to back balance, therefore less torque on your hands as you grip the camera. You will notice the camera will want to point up with a WA setup.

Gotta' add my 1 cent (due to Fed increasing interest rates

My Ikelite SLR-DC housing for the Canon Digital Rebel comes in barely 1/2 pound negative with standard dome port and a single DS125 strobe. With 2 DS50 strobes and EV controllers (all with Ikelite's SA100 ball joint arms) maybe a tad more negative. Still able to let the whole thing go in mid-water do a gear adjustment while it's slowly sinking and catch it before it gets away.

I NEVER in over 20 years of underwater shooting liked anything more negative than that. I've seen "super-size"dome port users add 1-2 lb. ankle weights to counteract the buoyancy (which as others also stated adds lots of wrist fatigue over the course of a long trip.) One photographer I know even with light dual strobes (Sea and Sea 90s I think which are almost positive?) swims with a rig close to 3-4 lbs negative! Maybe she's used to it but when I pushed my Digital Rebel housing towards her she was pretty impressed with the buoyancy difference. No manufacturer can guess what an individual user will use strobe wise, arms, extras etc. and guarantee neutral buoyancy.....I'm sure the Nikon D70 body will be close to the Digital Rebel in the Ikelite SLR-DC housing.

I've played with a Canon EOS 1DS and lusted after it. Then I analyzed how much more $$$ I'd have to travel if I used a Canon Digital Rebel. Same sensor as the Canon 10D, plenty of pixels for publications and I can buy 4 of these lighter weight bodies for the approximate cost of 1 EOS 1D MKII. Also decided this old man's wrists, elbows and legs for swimming a system through the water would appreciate traveling with the lightest possible tool for the job....

YMMV

David Haas

There is also a safety issue with using a rig that is very negative. With a pound or two its easy to either compensate for total diver bouyancy by keeping yourself negative and kicking more or to keep you and the rig negative with a bit of air in your bc. If you need to ditch your rig you won't go shooting to the surface.

But if your rig is many pounds negative in adition to the heft and ability to handle body position while shooting you will likely have to compensate with lots of air in your bc just to keep from walking on the reef. Then if you ditch you just might rocket skyward. In a situation where you are willing to part with your $8k rig you might not have the presence of mind to find your dump valve either.

But I don't think camera weight is a big factor in overall weight of the system. Housing strobe and arms also play a big role so there are lots of ways to compensate for a heavy camera.