- Banned
- #21
Pawel Achtel
Banned
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- Oct 12, 2007
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- Location
- Tasmania
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Deep Atom will look even more amazing when filled with 2 Epic's and one Atom...
Counting the weeks to get this baby deep down to get some astonishing images in the Seas, Oceans, Lakes and Cenotes of the WORLD...![]()
Ketch, It's great to hear that you are so enthusiastic about filming underwater.
But, as impressive as Atom and two Epics may sound, flat ports produce poor (like very poor) results underwater no matter what is behind the port. You can expect resolution lower than standard definition on the edges and strong distortions with focal lengths 50mm or wider (anything other than macro subjects). It is unfortunate that underwater ports so greatly affect the performance of otherwise impressive lenses and cameras.
Other limitations are that convergence can not be set because the lens must be exactly at 90 degrees to flat port. Otherwise, you will get beautiful rainbows everywhere, not to mention massive geometric distortions.
While all those limitations can be somewhat reduced in software, when there is no resolution to start with, the results are never going to be great. Also remember that, what looks like a great picture on the Internet, may not look that flash on a big screen.
There is heaps of reading material and samples on the Internet. Here are some:
http://home.swipnet.se/marinls/domeuw.html
http://www.hydroflex.com/site/helphints/flatdome.html
http://www.camerasunderwater.info/optics/lenses.html
http://www.camerasunderwater.info/equipment/olympus/c8080/index.html
Instead of putting a beam splitter behind a flat port, a solution great for macro subjects only, I'd consider making a finely selected dome system for optimal angle of view, focusing distance, interocular distance range, etc... It will most likely be limited to a single specific lens but, underwater, you don't usually change focal lengths, you use the widest lens possible and, if it is too wide, you just get closer to the subject.
Remember that anything more than 2-3m away, will be rendered muddy, low contrast and soft underwater as water is poor optical medium.
As I mentioned before, test, test and do more test. Why not to shoot a resolution chart through a flat port (aquarium glass) and see what you are going to get from your Deep Atom? Takes couple of hours to do and the results will give you a lot of food for thought.
What I'm trying to say is that there is no point putting a Ferrari V-12 engine on a cart with wooden wheels. It's not going to go any faster regardless of how impressive the engine may be and how much money you spend tuning that engine. :smile5:
You can probably achieve much better results with smaller chip cameras because it is easier to design correct sized underwater optics allowing smaller dome port and shorter interocular distances. Underwater, it is the port that is the limiting factor, not what is behind it. There are less challanges to overcome with smaller chip size (1/3" to 2/3") than it is with S35, which requires large ports that are too large for practical stereoscopic (3D) imaging.
Best Fishes,
Pawel