Micro 4/3 based UW filming system, what to choose, housing, port lens combo ??

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jagge

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Hey

I am considering investing in a m43 based UW film setup, BUT I am very confused about all the options, dome sizes, optics etc. So it would be great with a bit of help to avoid the biggest pitfalls :0).

It is replace a old bluefin house and a large Sony HDV based cam.

I am considering the Panasonic GH3 or GH4 that is coming. Now I am ceartainly not on unlimited budget so for me the biggest task is to find the right combo of parts that makes the most sense in a "bang for the buck" kind of way. I have been reading and it seems that the dome port choise combined with optics is crucial. I was thinking that I need a glass dome. It also seems that the only "cheapish" glass domes are teh zen domes. Now what would be a good GH3 setup. Its not about macro, most emphasis would be UW landscapes, and small cetaceans (length approximately 1.5 m) filming quite close up, in a captive environement. The animals will typically be 1 to 3 m away from the cam.

I have seen ok reviews of the 9-18 mm olympus lense and the panasonic 7-14 ditto, but I am confused about how to best match those to the best "cheap glass dome".

I would lowe to be able to make those half/half UW / air shots as well.

Hope this all makes sense, and someone can point me in the right direction, avoiding the biggest pitfalls.

Best wishes

Jakob


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Hi;

You would use the Zen DP-170-NM along with a 20mm extension and 7-14 gear. Not quite sure that you would need the extension with the 9-18, it's pretty short.
You would not have manual focus.
Nauticam also has a new 6" dome port that will have both manual focus and zoom.

The GH4 should fit the GH3 housing, btw. I think it would be a very good choice. You might want to look at the BlackMagic Pocket Cinema Camera, it uses m4/3rds lenses and ports. But it has quite a large crop factor making w/a hard.

Jack
 
thx jack. when manual focus isnt possible with the zen dome, I am wondering if the autofocus in movie mode is reliable enough on the GH3 / gh4 for UW filming ? I guess I would use push focus, or try to work with focus zones. Do you have any experience with that ? Best wishes

Jakob


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The 9-18 has a max field of view of 100 degrees diagonal. At one meter distance this means your max size subject is 2 meters. The panasonic lens has 115 diagonal and around 105 horizontal it will increase your horizontal field of view of 30%. But then at the zoom end one will be a 36mm lens good for portraits the other will be a 28mm lens which is a tad wide. If you film with lights an acrylic dome will be sufficient if instead you have reflections and backlit situation look for glass as it is usually coated on both internal sides with anti reflectance. The 7-14 lens needs a larger dome than the 9-18 lens. I would first consider what lenses you need and then build a system around it
 
Hey, thanx a bunch for the advice. Now my problem is that I know what I like but not what lenses are nescessary :0). Anyhow 2 m coverage at a m distance sounds very adequate actually. I will not use strobes, and ceartainly shoot most from 1 to 4-5 m. depth. So the 9-18 does not sound off at all. Now what zen dome would you recommend for that one, if I go for a GH4 ? Any housing recommendations ? Best wishes Jakob


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I have the GH3 (well I did till I sold it last week!) and await the GH4 - which will fit in my NA-GH3 housing, barring the issue with the command dial.

The Zen DP170-NM is the ideal dome for both the 12-35mm and 7-14mm - alas Zen/ReefPhoto have got issues with their manufacturer - and I'm starting to think the glass element is made from Unicorn tears - its only been on back-order since January.....!!! last I heard was that they were yet to receive any and looking at 2/3weeks (this was the 11th of April)

I've kept to Panasonic lenses, as the GH3/4 will perform auto corrections for those lenses - add the fact that the GH4 will also be able to focus faster using the new DFD (Depth from Defocus) feature - but only Panasonic lenses..

Originally I was going to stick with just the 12-35mm lens, but on further usage, it was apparent that the extra coverage of the 7-14mm was worth the investment, sadly the 12-35mm has IS, which does help while the 7-14mm does not. But getting closer to wrecks, but still having lots of coverage is a good trade off.

The 9-18mm is soft, soft and soft - the old saying, buy cheap, buy twice...
....did I mention I purchased one, only to go and get the 7-14mm!!!!!

The Blackmagic cameras are also a good choice, but that is a whole new ball game in terms of recording, grading, editing. Pros / Cons. If I had the time and skill to use one, I think I would be using a BMPCC now..

The NA-BMPCC housing (for the BMPCC) also introduced a new version of the acrylic 6" dome (mentioned by Jack) which provides an additional knob, which given the extra focus rings attached to the lens lets you, with the BMPCC control both zoom AND manual focus. This Dome however has been stated doesn't fit the NA-GH3 (lens release is effected) so for the Panasonics you are stuck with the camera doing your focusing (* on the lenses, not having focus rings)

As to focus, you can turn off CAF and customise the AEL/AFL button to perform single press AF (while recording too). Due to the u43 sensor, using an aperture > f5,6 or higher you can get a decent depth of field - so you shouldn't have to worry about the focus wondering, once locked onto your required subject.

Please free feel to ask any questions about the GH3, as you can see from my signature I'm quite invested in the GHx and Nauticam setup!
 
Last edited:
Trickster is right about the image stabiliser. The 7-14 is a great lens but all the footage I see shot with it is shaky.
As you are focusing on portraits it will be important to shoot wide and close at the same time
In that case I would think the 12-35mm with IS from Panasonic is actually the best choice with a 6" dome or a 7" zen dome if you don't shoot backlit acrylic dome will be just fine
 
I have the

As to focus, you can turn off CAF and customise the AEL/AFL button to perform single press AF (while recording too). Due to the u43 sensor, using an aperture > f5,6 or higher you can get a decent depth of field - so you shouldn't have to worry about the focus wondering, once locked onto your required subject.

Please free feel to ask any questions about the GH3, as you can see from my signature I'm quite invested in the GHx and Nauticam setup!

Wow this Forum is GREAT, thx a lot to anyone taking the time to help a newbie, its amazing the specific experiences can be tracked down here fast :0).

Now regarding the setup it all sounds very interesting. I do thing one press AF will be the way to go for me, combined with knowledge of the DOF zones and f stops. There must be tables regarding how they behave in water ??

Anyhow the GH4 sounds very tempting allthough I could propably get by with teh GH3. Now the 4k feature does make it more longlived especially considering the price of the UW housings... Anyhow great advice. What I cant figure out is whether to go for the 7-14 or the 12-35. I do hear a lot about wideangle being important. What viewing angle would 12 mm give me with the zen dome ?

Best wishes

Jakob


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---------- Post added April 19th, 2014 at 01:35 PM ----------

Trickster is right about the image stabiliser. The 7-14 is a great lens but all the footage I see shot with it is shaky.
As you are focusing on portraits it will be important to shoot wide and close at the same time
In that case I would think the 12-35mm with IS from Panasonic is actually the best choice with a 6" dome or a 7" zen dome if you don't shoot backlit acrylic dome will be just fine

BUT is the 12 mm not to narrow, that is my main concern, maybe not. Regarding the acrylic dome. I will not use lights on cam I think, BUT since i will be shooting a lot right under the surface, cant sunlight and shooting towards teh sun be a issue with an acrylic dome ?

Best wishes

Jakob


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Jakob,

I think personally you will end up with both lenses ;-)

But if I had to choose now. It would be the 7-14mm.

Here is a DoF calculator.
http://www.dofmaster.com/dofjs.html

You can select 43 sensor size and the lenses to get an idea of what DoF you will get at different apertures.

12mm behind a dome is 84' AoV I think, but can't remember off hand.



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thx man I will check that out for sure. Good info.


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https://www.shearwater.com/products/perdix-ai/

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