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acuevas

Rig too negative

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Yesterday I went to the pool with my complete rig for the first time, you can see more details about it here

First thing I noticed, was that my rig is too negative underwater.

 

My configuration is:

- Aquatica Housing AD7000.

- Aquatica Mini Dome.

- Aquatica Extension Ring 18456.

- Aquatica Zoom Gear 48717.

- Nikon D7000

- Tokina 10-17

- 2 x Inon z240

- 2 x 8" ULCS arms

- Stix floats

 

post-24761-1315853107.jpgpost-24761-1315853119.jpg

 

I think I will need to get some jumbo Stixs, but I'm not sure how many floats I need.

Does anybody in the forum has a similar rig that can give me an approximation about how many jumbo floats I need?

 

When not in use, this is how I put the rig underwater and out of the water too:

post-24761-1315853390.jpgpost-24761-1315853415.jpg

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My rig is not identical but then again, not totally different.

I use 4 XL floats on two 8" arms and 2 L floats on two 5" arms.

With the Nexus, D90, Inon Z240, this gives less than 1 lb negative using the mini-dome.

You can only get two XL floats on each of your 8" arms.

 

Perhaps others here can address your exact rig but if you get no better info, I would get a pkg of 4 XL (Jumbo) floats.

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Hi Andres

The easiest way I found to find the proper weighting is to buy a digital fish scale, fill a large container with water, and then weigh your rig rig without any flotation attached to get the in water weight.You can then determine how many and what size stix floats you need by going to http://stores.4gdphoto.com/StoreFront.bok. They list how much flotation each individual float gives. I found that I prefer to have it slightly negative as it seems to give the camera better stability in mild surge. Hope you find this helpful.

 

Mike

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Hi Andres

The easiest way I found to find the proper weighting is to buy a digital fish scale, fill a large container with water, and then weigh your rig rig without any flotation attached to get the in water weight.You can then determine how many and what size stix floats you need by going to http://stores.4gdphoto.com/StoreFront.bok. They list how much flotation each individual float gives. I found that I prefer to have it slightly negative as it seems to give the camera better stability in mild surge. Hope you find this helpful.

 

Mike

 

Today I followed your advise and I weighed my complete rig in a tank with fresh water.

My rig weight in fresh water 1230 gr

 

If I'm able to put 2.5 jumbo floats on each arm, that will be a total of five Jumbo floats for a total of 795 gr of buoyancy, with that my rig will be 435 gr negative.

I would like to have a rig with no more than 200 gr negative, that including a 45° viewfinder, Sola 600 and the clamp for the light that I pretend to acquire soon.

 

In summary, I'm a little short in buoyancy, I don't want to add another section to the arms. In the past I used two 8" sections on each side and I like it more with only one section.

 

I have more Stix floats size L that I'm not using, so I added 8 floats to my rig and with that it's near to 100 gr negative.

As I cannot add those floats to the arms I'm thinking to attach them to the bottom of the housing, I will play with that configuration a little to see how stable that configuration ends.

If the housing tends to rotate too much, I will put jumbo floats to the arms in order to give it more buoyancy on the top.

 

I will report back if it works or not.

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I have 4 jumbo stix floats on each side (8 total) and I'm using 4 of the older style ULCS buoyancy arms with my D300 / Aquatica / Tokina 10-17 / Ike DS-125 setup. It is just slightly negative.

 

JP

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Remember that you and your rig will be more buoyant in salt water than in fresh water.

 

Yes, that will need some fine tuning. I have it in mind.

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