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thani

Member Since 13 Aug 2008
Offline Last Active Today, 12:15 AM
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Posts I've Made

In Topic: How would an 8 inch dome perform with an 16mm FF equivalent fast lens?

03 February 2015 - 09:38 AM

Hi Drew, Thanks for correcting me. The crop factor is actually 1.39 and I totally forgot to multiply by it. So here what I think the equation off Speed Booster For Canon EF (full frame lenses) which has a magnification of 0.71 and sony Super35 mm which has a crop factor of 1.39:

FF lens focal length x Speed Booster magnification x Crop factor = Full Frame equivalent Focal Length
In my case at the widest 16mm:
16 x 0.71 x 1.39 = 15.79 almost 16mm FF
At the full Zoom 35mm:
35 x 0.71 x 1.39 = 34.54 almost 36mm FF

Therefore, the speed booster from Metabones gives me the advantage of a FF lens on a Super35 :)
It also makes the lens faster by one f-stop. My 2.8 becomes a 2.0 :)
I have asked on the Sony community about the corner sharpness when using the speed booster and got a confirmation that it is good. And as you've said for motion/video it will not be noticeable.
With this setup, in air, the lens doesn't show distortion at the widest and it produces a little wider feild of view than the 12mm Zeiss.
Do you mean the distortion will be more obvious behind the dome in water?

Kevin Palmer, who is a very supportive customer oriented person, from Reefphoto has replied to an email I sent to him yesterday clarifying that he took those stills with the Zeiss 12 mm behind a 7 inch dome at 5.6-8f. Now the 12mm on 1.5 crop factor is equal 18mm FF. The images that he produced were amazingly sharp and distortion free.

Please remember I am not using video lights and that I'd like to take advantage of the fast lens I am using. I know it's quite a challenge.

Drew, is it possible to correct the 11mm to 16mm in the post title?

In Topic: Help! I'm going blind

24 October 2014 - 09:37 AM

Does it make you swim around in circles? :)

Actually, I think it does Peter :)
Last time I used the lens I got separated from my buddy and ended up where I started the dive. Just kidding. It really works. I am used to wearing contact lenses and it solves the reading/focus issue for me which is a big challenge when you only have the option of manual focus on cameras such as Blackmagic cameras.
I hope others can benefit from this solution.

In Topic: Help! I'm going blind

24 October 2014 - 02:21 AM

Hi guys,

I was thinking of the same prescriptiondivemask but then I run into the disposal contact lenses for close reading. You just wear one in one eye off course :) and it takes a bit adjusting to it.
It works and now I always wear one when shooting. As a refrence I use it with Blackmagic 2.5k & 4k cameras.

In Topic: fogging dome port and lens while video recording

02 September 2014 - 09:01 PM

Any other ideas or experiences like that? Am I right with my assumptions? Should I have always prepared the camera in an AC-controlled environment like inside the ship?
Thanks


I always setup in AC places whenever available (boats or hotels). Done that in Dubai, Redsea & Malidives. Never got fogging issue. If I have to setup ouside in warm/humid places, fogging will occur when I hit the cooler ocean waters :)

In Topic: Upcoming Panasonic GH-4K

01 August 2014 - 10:39 AM

Hi Jean,

I already invested in a Zen 8 inch dome with an Aquatica mount, can I use the same for your GH4 housing?
http://reefphoto.com...roducts_id=4569

I have the panasonic 7-14 and contemplating to buy the faster 12-35mm 2.8 cause it's faster. Is the above dome good for such lenses?