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Underwater DoF calculator ?


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#1 SteveB

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Posted 04 March 2009 - 07:33 PM

Is there such a thing or something I can get some real numbers from, in order to get a feel for actual distances ?
Life used to be simple in air using cameras with manual focusing and an aperture ring. Just look down at the lens and the answer was printed there. Didn't take long to know how much was needed.

I found some articles on dome port virtual images but I have a p/s (Oly C5050) with a flat port. I also have wide and macro wet lenses. I'd like to know how close I can get to a foreground object and still get the wreck sharp with the wide angle, etc.

Steve.

#2 Deep6

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Posted 04 March 2009 - 08:03 PM

I found some articles on dome port virtual images but I have a p/s (Oly C5050) with a flat port. I also have wide and macro wet lenses.
Steve.

Steve,
I can not find the specs. on your out of production camera. If you find a p/s camera with the same size sensor as your Olympus, convert your air focal lengths to water (roughly x 1.33, e.g. a 6mm lens = 8 mm with flat port and air saltwater interface, whatever for w/a & macro), and plug in the values at the below link.
http://www.dofmaster.com/dofjs.html

Happy pencil sharping,

Bob

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#3 SteveB

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Posted 04 March 2009 - 08:18 PM

Perfect.
1.33 is the magic number I needed. Thanks.

Steve.

#4 Deep6

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Posted 05 March 2009 - 09:20 AM

Perfect.
1.33 is the magic number I needed. Thanks.

Steve.


Just to be clear, that is an approximation for a flat port in salt water. A dome port would not change the apparent focal length; your w/a & micro would.

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#5 jlyle

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Posted 05 March 2009 - 12:05 PM

The DoF for the 5050 + WA lens adapater is amazing, even at F/1.8.

This is at F/4:

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