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Sony a7sIII worth it? - Housings Question

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Posted (edited)
On 4/20/2021 at 9:17 PM, Whipauee said:

A bit of news, I just picked up a Sony a1 and all the buttons work in the controls work a7s3 Nauticam Housing. Except for the controls on the left top for Still frame rate and focus, Continuous, Single and DMF and Manual.I got the a1 for surface work not UW but just tried it for fun and was soo surprised. The same experiment with the a7r4 was not as successful in the Nauticam housing.     

I was on the way to test the a7s3 with 16-35mm in a 180 dome (Nauticam) for balance and buoyancy in this configuration. Bad weather prevented a real field test. But this configuration balances better than the WWL-1 with a flat port and 35mm prime in fresh water IMHO.

I'm back in salt water in 2 weeks, was hoping to narrow down my flying travel field kit but maybe I'll take everything! UGH!

Hi Whipauee, 

On your test of the nauticam 180mm dome with the 16-35mm, what length of extension port did you use, and how did you like the balance and buoyancy of the setup ?  Did you use the recommended length in the chart ?  Thanks ! 

 

Edited by Wira Wijoga

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On 5/11/2021 at 6:00 AM, Whipauee said:

Back from diving a week around Roatan. Have not imported or analyzed footage yet. but the a1 seemed to consistently display the overheat icon in the a7s3 housing while shooting clips underwater. The a1 never did shut down.

This is where an aluminum housing may have some benefit as the housing would act as a big heat sink to transfer the heat away. Probably doubly effective in cold waters.

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Posted (edited)
On 5/11/2021 at 12:00 AM, Whipauee said:

Back from diving a week around Roatan. Have not imported or analyzed footage yet. but the a1 seemed to consistently display the overheat icon in the a7s3 housing while shooting clips underwater. The a1 never did shut down.

This is probably normal (at least it is for the a7siii). Do you have the the "Auto Power OFF Temp" setting set to Standard or High? If you don't want to see the warning, set it to High and you should be good.

Edited by rgilkes
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Wira,

My solution is a bit of a Rube Goldberg. Starts with a N100 to N120 Port Adaptor, then a Extension ring 60, and last a piece that adapts the Nauticam system to a subal system that allows me to use my Subal 1800 Dome. I talked with Phil at Nauticam in Ft Lauderdale and he first suggested a Extension ring 70. I pointed out the the Nauticam to Subal adaptor was about 10mm so we decided on the 60. The rest of the setup included 2 Keldan 4X video lights and 2 Nauticam 70x250mmm Carbon Fiber floats. This was targeted to use the Sony 16mm-35mm lens. The rig was near perfect in salt water. I tested in fresh water and when submerged it weight about a pound. In salt water a curious phenomena seemed to take place, at the surface down to 10 feet the rig was slightly positive, then at about 30 feet and 10 mins into a dive it would be neutral or slightly negative. System is vacuumed pumped as well. I have no Idea why that would be the case since nothing compresses, maybe temperature was an influence, who knows. 

After importing the footage shoot in SLog 3 Gamma 3 with AutoFocus, the results were rather good. Most everything was in focus using the wide auto focus setting. I have found that most effective when trying to shoot video of unpredictable movement. On import into FCPX I applied the Sony Camera LUT to the footage and on cursorily checking the parade waveform I suspect very little adjustment in Color correction will be necessary. Oh, and yea, White balance at shooting depth with a Keldan grey card that flips over to shoot a small chip chart. 

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rgilkes,

What a good point about the a1, I just change the Auto Temp setting to High, The default is set to Standard. I then checked my a7s3 and it is /was set to standard but I changed it to high as well. 

Of note the a7s3 in standard temp mode never showed the temp warning where the a1 did.  I'll be curious to see how that adjustment will show or not show the temp warning on my next set of dives.  July 4th out of Miami to the Bahamas on the Juliet Sailing liveaboard.

Note to self: Take a dang wrist slate down and after white balance shoot slate with particulars of that dives set up. I can figure  lot out with the limited metadata in FCPX for video, but its not quite like the metadata you get shooting stills and reviewing in Capture 1.

After 25 dives things can get a bit jumbled.

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Posted (edited)
15 hours ago, Whipauee said:

My solution is a bit of a Rube Goldberg. Starts with a N100 to N120 Port Adaptor, then a Extension ring 60, and last a piece that adapts the Nauticam system to a subal system that allows me to use my Subal 1800 Dome. I talked with Phil at Nauticam in Ft Lauderdale and he first suggested a Extension ring 70. I pointed out the the Nauticam to Subal adaptor was about 10mm so we decided on the 60. The rest of the setup included 2 Keldan 4X video lights and 2 Nauticam 70x250mmm Carbon Fiber floats. This was targeted to use the Sony 16mm-35mm lens. The rig was near perfect in salt water. I tested in fresh water and when submerged it weight about a pound. In salt water a curious phenomena seemed to take place, at the surface down to 10 feet the rig was slightly positive, then at about 30 feet and 10 mins into a dive it would be neutral or slightly negative. System is vacuumed pumped as well. I have no Idea why that would be the case since nothing compresses, maybe temperature was an influence, who knows. 

Did the rig become slightly more buoyant again as you're finishing the dives in the shallow (5m) ? my nikon rig does the same always more buoyant in the shallow less than 6m !

Thanks for the info on your rig.  Was asking because my 16-35mm Nikon setup with the 80mm extension ring+Nauticam 180mm was so buoyant underwater, and even worse that it was soo hard to bring it down underwater when i was swimming with whale in Tahiti.  I'm just thinking if i should sell my 80mm extension ring, now that i found out my nikon 16-35 fits into my housing+ N120 extension ring 30+ Nauticam 180mm dome set which is much less buoyant (intended for 8-15mm + 1.4 tc setup) even though the lens positioned so close to the dome's glass.  

 

Edited by Wira Wijoga

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2 hours ago, Wira Wijoga said:

Did the rig become slightly more buoyant again as you're finishing the dives in the shallow (5m) ? my nikon rig does the same ... always more buoyant in the shallow less than 6m !

Thanks for the info on your setup.  Was asking because my 16-35mm Nikon setup with the 80mm extension ring+Nauticam 180mm was so buoyant underwater, and even worse that it was soo hard to bring it down underwater when i was swimming with whale in Tahiti.  I'm just thinking if i should sell my 80mm extension ring, now that i found out my nikon 16-35 fits into my housing+ N120 extension ring 30+ Nauticam 180mm dome set which is much less buoyant (intended for 8-15mm + 1.4 tc setup) even though the lens positioned so close to the dome's glass.  

 

The lens may fit in the setup with shorter extension, but won't be correctly placed optically and this introduces distortion and chromatic aberration to the image.  The 80mm ring places the lens at the correct spot.

When considering buoyancy the only thing that matters is the displaced volume>  The difference in volume between the 30 and 80mm extensions in 0.00056 m3, so the buoyancy change going to a 30mm ring from an 80mm is approximately 0.56 kg, so strapping on a 1lb dive weight will have about the same impact and is what I would do in that situation.

 

Regarding the buoyancy change again only a change in the volume displaced will impact buoyancy.  For example the float arms may flex a little at depth or the the o-ring on the housing back may compress to the point that metal to metal contact occurs, preventing additional volume change. Likewise the dome may be pushed further into the o-ring until it can't compress further.  Vacuum won't have any impact apart from causing the compression to occur shallower than it would otherwise.  The reported vacuum achieved on such system is equivalent to the housing being submerged 2m.  Pulling a vacuum will reduce the weight of gas in the housing, but this would be a fraction of a gram change.

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Posted (edited)
On 5/15/2021 at 3:45 PM, ChrisRoss said:

The lens may fit in the setup with shorter extension, but won't be correctly placed optically and this introduces distortion and chromatic aberration to the image.  The 80mm ring places the lens at the correct spot.

When considering buoyancy the only thing that matters is the displaced volume>  The difference in volume between the 30 and 80mm extensions in 0.00056 m3, so the buoyancy change going to a 30mm ring from an 80mm is approximately 0.56 kg, so strapping on a 1lb dive weight will have about the same impact and is what I would do in that situation.

 

Regarding the buoyancy change again only a change in the volume displaced will impact buoyancy.  For example the float arms may flex a little at depth or the the o-ring on the housing back may compress to the point that metal to metal contact occurs, preventing additional volume change. Likewise the dome may be pushed further into the o-ring until it can't compress further.  Vacuum won't have any impact apart from causing the compression to occur shallower than it would otherwise.  The reported vacuum achieved on such system is equivalent to the housing being submerged 2m.  Pulling a vacuum will reduce the weight of gas in the housing, but this would be a fraction of a gram change.

Thanks for the info Chris. Will try the weight on my next dive + ext 80 for sure, sounds easy enough ! 

Also will try to shoot more with my 16-35 in the N120 extension ring 30+ Nauticam 180mm dome set to see some more result, I only did 2 dives trying the setup on my last dive trip to Nusa Penida and  Raja Ampat last month. The result were ok, but then again it was only few shots on each dive. I saved a big space on my pelican with the ext 30 instead of the 80. 

 

Edited by Wira Wijoga

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