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

The weight is a serious concern as anyone housing a 1Ds can tell you.

Not to stray off topic too far, but I have to laugh every time I read someone saying "the weight of the 1D/s/mkII is a serious concern". It's a single pound give or take. I have a D60 with a battery grip, and yes, it's lighter than my MkII, but not exponentially. Above water, my D60 setup is heavy, as are most SLR setups. Underwater, it's not.

Think of it this way, 70% of Americans are overweight and 20-30% are obese. Rather than focus on the 1 pound of extra weight on their camera, maybe they should pay attention to the extra 20 pounds on their waist (mine included).

Sorry, I'll get off my soapbox now...

The weight is a serious concern as anyone housing a 1Ds can tell you.

 

Not to stray off topic too far, but I have to laugh every time I read someone saying "the weight of the 1D/s/mkII is a serious concern". It's a single pound give or take. I have a D60 with a battery grip, and yes, it's lighter than my MkII, but not exponentially. Above water, my D60 setup is heavy, as are most SLR setups. Underwater, it's not.

 

Think of it this way, 70% of Americans are overweight and 20-30% are obese. Rather than focus on the 1 pound of extra weight on their camera, maybe they should pay attention to the extra 20 pounds on their waist (mine included).

 

Sorry, I'll get off my soapbox now...

Maybe you should try holding one that's a pound heavier then. The difference is huge. I'm not complaining about travel weight but rather handling and an extra pound is very significant. Above water I could care less about the weight.

I think camera weight both above and below the water is always a personal thing. If you own a heavy camera you just get used to it UW and it becomes part of your buoyancy and trim. The Nikonos RS was a very good example of a heavy camera.

My D100 is neutral in the water. But my subtronics alphas are significantly negative. When I shoot available light (no strobes) I have to add weight (to me). Having a heavy camera doesn't bother me at all.

But others differ. Last week in the Red Sea UWP Ed Peter Rowlands was there. We were both shooting Subal housed D100s, for strobes I used my 2 heavy subtronic alphas, while Pete used a much lighter single Inon 220. But he still went to the trouble of attaching buoyancy to his rig so that it was neutral and handled better. I was happy diving with my engine block...

Alex

Maybe you should try holding one that's a pound heavier then

I have, and it makes no real difference to me. Like Alex said, weight underwater is a personal preference. If I wanted to pick my camera based on weight I'd probably be looking at a Minolta Dimage or Sony T1, not a D60, MkII, or any SLR.

A quick additional point - I think neutral buoyancy and horizontal pitch of a system are much more essential for video than stills. Photographers who shoot both would be better with two neutral systems. Alex

I can't believe anyone who's used very negative camera would ever say that it doesn't make a difference. Alex didn't say that. He just said that he adjusted to it and it didn't bother him.

The size and weight of SLR's doesn't automatically make them negative underwater. For the most part my Nexus D100 is quite trim and Alex's Subal is reportedly neutral ignoring the strobes. If there was ever a need to soapbox it would be to complain that manufacturers consistently fail to consider proper trim in their designs, not to complain about those who desire their rigs to be neutral. I don't think a desire to use an SLR should dictate that they handle like diesel trucks. We use SLR's because they're imaging performance and optics are superior. We should expect the ergonomics to be superior as well.

As to personal preference, I find heavy rigs tolerable for wide angle but not for macro where holding an awkward position can be impossible with the camera pulling you over. I've seen others wear ankle weights to help with a macro rig that just can't be made trim. I use a handmade float that helps support my larger macro lenses. It provides 12oz of lift and makes a huge difference. Without it one-handed macro shooting is impossible. The 16-24 ounce difference between a pro body and one like the Kodak is enormous by comparison considering that housings rarely, if ever, compensate for the extra weight.

Yes, I agree with Alex that video is especially sensitive to trim since you have to hold a camera steady for an extended period of time. Being a videographer (or ex-videographer, can't decide which) I don't like heavy rigs. You can't hold a position indefinitely without bracing yourself or flailing in the water unless your entire rig (BC, body, camera) is properly trim. A heavy camera makes that very difficult.

It might be interesting to start a new thread on housing buoyancy, trim and UW ergonomics. There are a lots of interesting points being made. Plus it would be nice to see pix of home made modifications to help achieve neutral buoyancy. Alex

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The Subal D100 is slighty negative (port dependent) but mine is neutral when used with a Subal strobe case. My Subal D100 was the pre-production housing and differs from the actual production housings slightly, which have more wieght saving in the machining and is probably a bit lighter in the water.

It might be interesting to start a new thread on housing buoyancy, trim and UW ergonomics. There are a lots of interesting points being made. Plus it would be nice to see pix of home made modifications to help achieve neutral buoyancy. Alex

Done.

Good idea Alex.

While I'm typing I'll add my $0.02 worth. To point out the obvious, the bouyance depends on the housing design. It's probably too early to say the Kodak has a weight problem before anyone has a housing.

More obvious point: an extra pound will require about 1/2 liter in volume to compensate.

Even more obvious point: It's easier to add weight than increase buoyance.

Conclusion: get a DRebel, it's the lightest.

I prefer a neutral rig and smaller is better. Also, having just made a couple of beach dives in cold water, less weight at the surface is nice also.

Hi Herb,

Thanks for splitting the topic.

Craig: It looks like you made one post after/during the split. Can you copy it over here?

Re: the Aquatica housing for the Kodak. I think we will have a good idea about the in-water weight by the middle to end of July. According to Blake, the housing will have a contoured back to fit the ProSLRn's lower "pooge." (That's a technical term) This may make the housing more compact, but it may also mean less trapped air = less buoyancy. We'll just have to wait and see.

It should be fairly similar to the S2pro housing, which is a bit negative with the macroport. It's about neutral (maybe 6 oz negative max) with the 8" dome port.

Cheers

James

I agree with Herb's point that it is easy to add wieght to a rig than buoyancy - curiously dive boats always seem to have lots of lead weights about the place!

A good example of this is Peter Scoones's digital betacm housing that he used to film the Blue Planet series. This housing is designed to be positive and has a tray underneath where dive wieghts can be fixed and moved to adjust buoyancy and trim. I can't find an online image, but there is one in UWP Magazine Issue 6 page 9.

But then as Herb points out it is easy to make a big housing buoyant, the problem is we don't want massive housings.

Alex

Right, and heavier bodies are likely to be negative UW since many believe that a smaller housing is better than a neutral one. While the pro body is more durable, the lightweight body is an advantage underwater. Not necessarily for wide angle, but for supermacro with a 200mm lens! I had to weight my Sea & Sea when I used it with an 8" dome port.

I'll post pictures of my foam lens ring when it's returned to me.

I can't believe anyone who's used very negative camera would ever say that it doesn't make a difference.

Believe what you want to Craig, I stand by my statement. I'm not suggesting that MY opinion is absolute gospel, rather that it's my OPINION. There have been a number of times when I was very glad that my housing was slightly negative (and by slightly I mean about 1 lb). Whether or not "a 1 lb difference is huge" or not is largely a matter of preference. I don't think it is, but you're certainly entitled to that opinion.

Alex didn't say that. He just said that he adjusted to it and it didn't bother him.

When I said that I agreed with Alex, what I meant was that I agree it's something you can get used to if you want, but again, that's my opinion, and it may not be true for you.

Back to one of my earlier posts, if weight is the deciding factor for anyone, maybe they should consider a DRebel like Herb mentioned. It's a kick-ass camera and it's very compact and light, something that can't be said for either the Kodak or the Canon 1d.

The one thing that I've consistently found is that no matter what the housing / camera combination is, the inherent buoyancy of the overall rig changes from day to day simply because of lens, port, strobe, and arm selection.

Not to beat a dead horse (I'll just kick it a little), a negative rig never bothered me until it bothered me. :wink:

I'm patiently waiting for a critter to crawl out its hole. My left hand is holding onto a rock as current and surge want to take me somewhere else. I'm holding the rig in my right hand with finger on shutter release. At the 10 minute mark my hand starts cramping. I can no longer hold the camera in my right hand. I switch hands to get some relief. The fish pops its head out of the hole. (I have world wide conspiracy theory about that) As soon as I switch hands back, the fish goes back in its hole. The process is repeated only each successive cycle requires less time to cramp. I contemplate digging the fish out of the whole. Images of Bill Murray reaching for gophers enter my mind.

Memories haunt me of using the 200mm lens with two Ikelite SS200 (approximately 44lbs/20kgs negative in water....each). A small lift bag attached to the front of the port might work. Maybe thats what the knob is on the outside of the port, a place to attach the lift bag!

When I used a small consumer digicam, I enjoyed the lightness of the rig, but rather than getting a hand cramp, I got an index finger cramp. I kept pushing the shutter release harder and harder to reduce shutter lag. It was as about as successful as pushing the already lit floor button to make the elevator go faster.

I always chose the small brick over the big neutral, but I'm now thinking I will put buoyancy into the equation. A negative rig is a real pain, especially when forget to put in the CF card before the dive. My next rig might be a Minox in an Ikelite MD case with penlight size strobes.

Well, Tom, I believe you never considered it when you posted your first reply. In just what way could losing a few pounds off my waist help with the bouyancy of my rig? If you're going to get on your soapbox, try not to look so ignorant.

And no, a "1 lb difference is huge" is not a matter of personal preference. Liking a heavy rig certainly is, but there is no denying that a 1 lb change in bouyancy hanging at the end of your arm is very noticable. Anyone can take a few weights into the water with them and verify that these things matter.

Your suggestion that people consider a Digital Rebel due to its weight makes no sense either. That camera is not in the same class a Kodak or 1Ds and anyone considering a full frame dSLR will not consider the 300D as a viable alternative. Of the two (or three) very high resolution SLR's, the Kodak is by far the lightest. That was my original point and it's valid. It was never a comment about handling above water. Ask people who shoot a housed 1Ds if their rigs are anywhere near neutral.

The original poster asked for comments on using the Kodak underwater and I specifically responded to that. The fact that it offers the resolving power of a 1Ds at half the weight is an undeniable advantage whether you personally value it or not. Unlike you, I don't consider the burden of an excessively heavy rig to be a badge of honor, and if I ever switched to a 1Ds it would be in spite of its excessive weight.

I agree, George. The best pygmy opportunity I ever had required free swimming in a mild current (no handhold). I had my 70-180 and if I hadn't been able to shoot one handed it was very unlikely that I ever would have gotten a shot. My rig set up that way weighs about a pound and a half. If I used a pro body the bouyancy problem would have doubled and I wouldn't have been able to manage it.

Craig said:

If you're going to get on your soapbox, try not to look so ignorant.

I understand you feel strongly about this Craig, but try not to be a d**k about it. I don't think you mean to be, but reading your (and Tom's) posts this morning got me thinking that way. It's the problem with message boards as a form of communication.

Sorry to jump in here Tom and Craig and mess up the flow of the thread, but I just want to bring in some outside perspective.

Cheers

James

It's the problem with message boards as a form of communication

I agree James. Rather than respond in kind and try and explain every comment that I've made, let me instead just give a reason why I prefer a slightly negative rig:

A few months back I was on a warm water wreck dive with my rig along with a few other divers. In the course of swimming through the wreck, one of the divers got his dangling console wrapped around a pipe as he went through a passageway. He could not extricate himself. I unclipped my rig from my BC, placed it on the floor of the compartment and swam over to help him free himself, which took all of a few seconds but in talking to the diver afterward seemed like an eternity to him. In this case, my "boat anchor" of a rig stayed exactly where I put it. Might it have done so if it was neutral? Yes. But might it have taken a few more seconds to get it securely placed? Yes. Does the safety of my fellow divers come first in this situation over my rig. Absolutely, but I would certainly like to know that my camera will be placed where I left it. Going through a couple of these situations has lead me to the conclusion that I prefer my rig slightly negative.

I don't shoot supermacro at this point, so I haven't experienced what George and Craig are describing.

I'm diving with the Aquatica A300, Dual Ikelite DS-125, Macro Port, 100mm Macro, Rebel. This is quite negative. However while diving in the Phillipines, I had to set it down a few times to help other divers. A few times I had to actually clip it off to a wreck so the currents woudln't take it off into the deep blue. I'm sure having a positive rig would be a little more difficult to manage.

Curtis

The D70 is light by SLR standards and the Ikelite new DSLR housing is big compared to some of the chicks magnet housings, but for one more refrence point, my D70 Ikelite housing with two DS125s and ultralight bouyancy arms is fairly neutral. It feels less than 1 lb negative though I haven't measured it.

I feel it is better and easier to use a system that is lighter in the water and better ballanced. You are often contorted in weird ways trying not to hit the reef while taking a picture and bouyancy makes all that easier. This has much more to do with the housing however than the camera itself because the housing adds so much more volume. I would not make a decision on camera based on bouyancy. There are easy ways to remedy either + or - bouyancy. Just add floats or weights as needed.

Hmmmm. One must consider the entire rig, including strobes. I'll stick my neck out and say most people prefer slightly negative. Even if the housed camera were neutral, strobes may make it slightly negative.

Now, assume we start just to the negative side of neutral (a best case scenario). If I added a lb. of negativity would I notice? Probably, and it would be noticeable in certain situations. Would I be OK with it? Probably.

Now, assume my rig, a negative aluminum housing with two Ikelite DS125, which are also negative (I went on a low carb strobe diet from my SS200's). Now add another pound of negativity. Now you are talking real negativity, probably the same as when I had the SS200's. Would I be OK with it? Probably. But I darn sure would notice it if I was used to something lighter.

Of course, I said 1 lb. of negativity. Not 1 lb. of camera. There's definitely a trade off of weight to volume.