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CheungyDiver

Member Since 26 Nov 2002
Offline Last Active Today, 06:52 AM
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#335862 Fully corrective port and wet lenses - Underwater Photogrammetry and camera c...

Posted by CheungyDiver on 15 August 2013 - 05:22 PM

Hi Pedro77

 

You could try Nikonos lenses. They could be way off the mark from what you need. There are literally tons of Nikonos lenses at giveaway prices. Try a few of them and see. From my own experience these lenses are made for water contact and most will not focus topside but UW they are tack sharp and distortion free. The higher end Nikonos RS lenses are even more sophisticated. I have re-chipped a few of them and have added aperture rings and they are probably the best UW corrected lenses there is. They are again designed by Nikon just for underwater photography. I have done some experiments myself. Even made a port that could make the Nikon 14-24mm working without too much corner distortion.  Let me know what camera and focal length I may be interested in studying this further.

 

Cheers

David




#334559 Yet another 3D Red Epic Housing

Posted by CheungyDiver on 18 July 2013 - 06:05 PM

Okay. Gotcha. The whales are pretty big even for the humpback calf.  Although the calf could get really close. I think you guys going to get some stunning footage. 

 

Brilliant idea to hook up two Deep X and an external mirror beamsplitter rig. I wonder which forum inspired Pawel with that idea ;)?  He will need some seriously good rig to stop all the movement. Salt water resistant stages. I can't wait to see that set up. 

 

 

Cheers

 

David




#333121 Anyone tried the AOI RGBlue video light?

Posted by CheungyDiver on 20 June 2013 - 07:06 AM

Its a big pond. The reason for warmer colour temperature and not to be confused with CRI or colour fidelity is perception. Warmer color temp helps me to perceives the subject and foreground in a way like using sunlight at really shadow depth- plus balancing a sunlit scene is easier. It is highly subjective. Not that noticeable and usually only when really powerful lights fill the shadows. Hence the saying the you can never bring enough lighting.    Shooting video raw these days makes balancing percieved colour easier. In fact it does not really matter as raw records much more information then AVCHD and even 422. As long as the exposure is correct and no clipping of the highlights and the shadows. In another post I discussed about HDR and ETTR. ETTR is something I am experimenting for video. I really like the way it helps to get the most details in the highlights in digital stills. It is another technique and I will not discuss it here.   Back to lights. Personally what I look for in lights especially LED is colour fidelity. Not all LED is made and give out the same color spectrum. In fact in the same production LED batch the colour rendering can vary. So absolutely matching LEDs is really just the 10% yield in a manufactured batch. CRI in the 90s is even more difficult to manufacture and strict electronic ballast is needed. One of the reason why RG Blue do not provide longer burn time is the power draw. The analogy is like a comparing a match with a gas hub. You get more heat from a gas hub. So more power is needed to get all the colour and a good balanced spectrum. Cooler colour light does not draw as much power but there is always sacrifice. Not saying the Fix neo or other LED lights are in that category but the CRI for lots of lights are in the 70s. Bigger battery will help longer burn time. One of the reason why Keldan Luna 4 is big and the Luna 8 bigger still. I think RG Blue may be looking into larger capacity battery.   BTW putting a colour filter does not provide more CRI. If the LED has missing lines in the spectrum then even recording in raw the colour is interpolated in post production. For Internet okay for TV network okay. Not cinema stuff. I am over simplifying this of course. There is also colour absorption downwards and sideways. I'll leave that in another post.   cheers




#332080 Add on to the Airlock Vacuum thread

Posted by CheungyDiver on 29 May 2013 - 02:35 PM

hi Andy

 

Yup and its the same valve used by myself and others for more than a decade. Repackaged, recycled and a dollop of marketing plus blinking lights and suddenly a must have. I have my hand pump with vacuum gauge also used for almost a decade. Still working.

 

cheers

D




#330199 Blackmagic Pocket Cinema Camera: Yes there will be housings!

Posted by CheungyDiver on 24 April 2013 - 06:01 AM

http://johnbrawley.w...in-your-pocket/ Oops someone beat me to it..     Just a run and gun footage. I think it is bye bye 5DMIII and GH2 or 3. Well not really if you want to shoot digital stills too.    A bit of rolling shutter but manageable. This will so eat into Go Pro on Multicopers and flying stuff.     The sensor is a 2.88 crop to be precise. For UW use a FE lens. Should be okay. I can't wait for it. 




#330105 Amphibico Genesis 700 for the NEX-FS700

Posted by CheungyDiver on 22 April 2013 - 06:06 AM

here are some pictures taken at ADEX of the Genesis and Rouge.

 

 

Attached Files




#329892 Blackmagic Cinema/Professional 4k Camera housings

Posted by CheungyDiver on 17 April 2013 - 05:23 PM

The "pocket rocket"BMDCC camera I am sure will outsell the other 4K camera. At under 1K USD its a no brainer for lots of people. It is a movie specific camera  and useful as B or C camera in tight situations or as a crash cam. Or a multicopter cam.  It will definitely eat into Go Pro 3 territory unless Go Pro comes out with a changeable lens POV cam.

 

From the specs point of view...2K prores is still very relevant. Faster workflow and less "frightening' in terms of post production hardware requirement. Just my opinion but I think UW manufacturers will not ignore this camera. It s not even reality until BMD delivers so a few months for design and prototyping then may be third or last quarter of this year before you see one. I hope to get the camera first and if the size fits I will modify some other housing and do some tests. I really like the MFT mount. Just about any lens could be adapted and used.

 

Right after the NAB hype the litmus test is delivery. No confirmed shipping dates and no out in the wild footage shot and graded yet.........wait wait wait.

 

cheers




#329789 Amphibico Genesis 700 for the NEX-FS700

Posted by CheungyDiver on 15 April 2013 - 06:20 PM

Too early for them to have all the adapters worked out for the ring and port. At the moment they are compatible with Sony e lenses. The 18-55 & 16 with 0.75 wide angle adapter. e lens is electronic zoom and focus. manual lenses could use the Aquatica focus port system. I am sure some existing gears could be easily made to work. 

 

There is no reason for not looking at more lens options for FS 700 especially when the CV. Odyssey  4K recorder could be accommodated in another housing (yet to be made) and also bdouble up as an Oled monitor. Just supply and demand. I am not sitting still. I will definitely look into the Metabone.

 

cheers

D




#329787 Nauticam Rossa for Red Epic/Scarlet

Posted by CheungyDiver on 15 April 2013 - 05:49 PM

I have been testing the Nauticam Rossa in Lembeh Straits recently. Too busy to do a full review but will later. Probably after the ADEX show.

 

Here are some teasers.

 

 

Attached File  LemRossa1.jpg   487.77KB   76 downloads

 

Not the best visibility at the time. The housing is well balanced. The slider weight at the bottom helps to adjust the centre of gravity of the housing. The finger tip controls are a joy to use. In this case I could balance the housing on the legs. I attached two ball arms in front in case I need more stability. Two more at the back and you have a quad-pods that could be made stable in any situation.

 

With the Nikon 105 VR macro it is more like 147mm macro. S35 sensor has a crop factor of approx 1.4 with FF lenses. I was surprised to see the size of the image on the screen. Great working distance too.

 

cheers

 

David

 

Attached File  LemRossa2.jpg   364.74KB   76 downloads




#329756 Blackmagic Cinema/Professional 4k Camera housings

Posted by CheungyDiver on 15 April 2013 - 04:47 AM

Thanks Davide.

 

Mystery solved. For stupid me.

 

So no excuse for other manufacturers then.....LOL




#328395 New Housing "Airlock" Vacuum from Backscatter

Posted by CheungyDiver on 23 March 2013 - 03:10 AM

The hand vacuum pump has a pressure gauge. Its similar to Backscatter and  Sentrythingy....

 

yes you check if the gauge and see if vacuum dips or not. Used this method since 1993.

 

Zero flood.

 

regards

 

David




#327046 New Housing "Airlock" Vacuum from Backscatter

Posted by CheungyDiver on 03 March 2013 - 12:31 AM

Gates housing vacuum check system uses the same valve. Gates uses a battery powered pump. This system has been around for a long time for high end video housings. I have my own version for DSLR for over 8 years on request from customers. Not one had serious problems. No electronic is a plus. The pump with the gauge is all you need. It is only partial vacuum like -0.5 bars which simulates about 5m depth. User could either leave vacuum in or purge it. Very unusual to have a sudden o-ring seal failure when the housing is under equal hydrostatic pressure from the water column. Unless user decide to whack the port on a rock. I had over 8 years and more than 60 people with these vacuum valves for both DLSR or video housings. I know they work. Keep it simple. Electronic only adds more stress.  The seal is checked on land and if seal is not working then the gauge will drop. Sort out the o-rings and then check again. O-ring either fail or working. They don't just decide to fail halfway. Anyway Backscatter version looks simple enough. Its the way to go for peace of mind.

 

Cheers


David




#316579 Panasonic GH3 is (almost) here

Posted by CheungyDiver on 17 September 2012 - 03:46 AM

Attached File  CineGH2.jpg   568.56KB   159 downloadsGH2 housing will not fit the new GH3 from the look of it. Its much bigger so Nauticam and others will need a to develop a new one.This UW imaging lark is getting exhausting with new cameras coming out every few months. Then people expect the housing to be available almost immediately......and then they want to sell their old housing....and so on.Change of topic I am making something for this puppy. For video. It needs a nice tube and nice AF coated glass port.Got one glass port done for Peter but his is a XF canon.Watch this space.CheersD


#284109 Seahorn snoot with Inon Z240

Posted by CheungyDiver on 09 June 2011 - 12:58 AM

Are there any fibre optic snoots commercially available?

/Bent C



Yup. I am making a batch.

Just PM me if you are interested. info@scubacam.com.sg

Go to the site here if you need to know more: http://www.scubacam.com.sg/blog/


Cheers

David