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Home: Inactive Forums: Underwater Video:
lens reflection/flare/halo

yhuubert
Novice

Jul 10, 2005, 7:48 AM

Post #1 of 5 (1770 views)
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lens reflection/flare/halo	Can't Post

Has anyone else sometimes notice a reflection/flare/halo when taking video underwater, when the light reflects back from lens to the dome port and then on to the final result, showing as 1-2 silver rings? I have attached some frame grabs to illustrate the point.

I am using an Equinox housing w Panasonic GS400 camera and sometimes an additional wide angle lens converter that came with the housing. These rings appear quite often and drive me nuts.

Can anything be done?

(This post was edited by yhuubert on Jul 10, 2005, 7:49 AM)

Attachments:

Grabbed-Frame-2.jpg (39.5 KB)

Grabbed-Frame-1.jpg (95.3 KB)

Grabbed-Frame-3.jpg (22.6 KB)

Grabbed-Frame-4.jpg (28.2 KB)

realfish
Novice

Jul 10, 2005, 12:20 PM

Post #2 of 5 (1749 views)
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Re: [yhuubert] lens reflection/flare/halo [In reply to]	Can't Post

[I had this problem and solved it. Your problem is harder to solve than mine due to the fact that it is a manually controlled housing, rather than an electronic one. You MUST get the lens as close to the front port as possibly, and with a "rod" style housing, that is not possible.
The surrounding light should enter the camera as if through a "tube" so as not to create a ghost image which bounces off the inside of the port, then back onto the tape.
Having said that, what you can do is get a W/A lens with NO SILVER RINGS on it...some Kenko or some Sony lens are that way, are not costly and are sharp.
Failing that, paint the rings with optical black paint-not a marker (Sharpie). These procedures all, however, work best if the housing has a flat port, not a dome...Mine is an Ocean Images Dolphin Pro, and after solving the problem the results are great.
an

yhuubert
Novice

Jul 10, 2005, 3:18 PM

Post #3 of 5 (1743 views)
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Re: [realfish] lens reflection/flare/halo [In reply to]	Can't Post

In Reply To

[Having said that, what you can do is get a W/A lens with NO SILVER RINGS on it...some Kenko or some Sony lens are that way, are not costly and are sharp.
Failing that, paint the rings with optical black paint-not a marker (Sharpie). These procedures all, however, work best if the housing has a flat port, not a dome...Mine is an Ocean Images Dolphin Pro, and after solving the problem the results are great.

I have these problems both with the additional W/A lens as well as without it.

The W/A lens is a Sakar 0.45x 58 mm lens. So when using that, there are no camera silver parts visible. I have attached 2 photos of the w/a lens and as you can see, many rings are created by it internally, so nothing can be matted or painted black there. Could other w/a lenses be better? Or do they also have similar appearance which would relfect on the dome? What do the Sony and Keno W/A lenses look like from the front?

Without the additional lens, the rings (just somewhat different) appear. In that case I could paint some part of the camera silver rings black, just I am afraid that even in that case the camera lens itself might relfect from the dome. Without the w/a lens the camera is also at least 2/3 inces from the dome port internal surface, which I assume makes things even worse.

Attachments:

IMG_9622.jpg (38.7 KB)

IMG_9623.jpg (32.1 KB)

realfish
Novice

Jul 10, 2005, 7:25 PM

Post #4 of 5 (1734 views)
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Re: [yhuubert] lens reflection/flare/halo [In reply to]	Can't Post

www.realfish-underwater.com As I said, with a manual control type housing that won't allow moving the camera forward, you are at a disadvantage. The W/A lens that I use is a Sony VCL-0637H on sale at the time for $40.00...a very sharp lens. It is all flat black with no silver rings to show as a ghost image. Others also have similar lenses.Try looking on eBay: "video wide angle lens".
There are pictures of the lenses at times.
Get rid of the lens with the silver rings and you should be OK...Good Luck!
an

realfish
Novice

Jul 18, 2005, 2:08 PM

Post #5 of 5 (1556 views)
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Re: [realfish] lens reflection/flare/halo [In reply to]	Can't Post

Wonder if you have solved your "ring"problem?
If not, you might try making a sun shade out of wet suit material that can slip loosely over the camera lens, then almost touch the inside of the housing front port. This forces the light to come in through a "tube".
Let us know your progress.
Art
an