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Philip HS

Strange red artefact with Panasonic 7-14 mm and 6" Nauticam dome

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Dear all,

 

I recently upgraded from Olympus E-PL6 / 9-18 mm / Olympus housing to OM-D E-M10 / Panasonic 7-14 mm / Nauticam housing because I wanted to go deeper and wider :laugh:

 

Now I get a strange red artefact on some pictures (examples enclosed).

 

Lens is Panasonic 7-14 mm @ f 7.1, dome port is Nauticam 6".

 

Of course, AF Illumination in the custom menu is turned off.

 

Any ideas?

 

P.S. Example pictures were taken on the Milford Haven wreck, the second Picture at a depth of 79 metres.

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Edited by Philip HS

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Does your camera have a red focus assist light? Or a self-timer red light? Do some selfies and see what comes in the way of a red light inside your housing when viewed from the front.

Edited by Tom_Kline

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Thank you for your input!

 

 

I think I identified the culprit: The Deep Shots Zoom gear. I hope I can get it exchanged for a black one ...

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Some more Pictures:

 

First pic: Selfie with Panasonic lens without zoom gear

 

Second pic: Olympus 9-18 mm lens assembly

 

Third pic: Selfie with Olympus lens with Olympus zoom gear

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Hi Philip

 

I have encountered this with some housing combinations fortunately when using big dome ports. The pop-up flash leaks light inside the port and illuminate it from behind. Two things you can do.... I once built a more "sealed" flash compartment from black masking tape for the pop-up flash.... or simply return the gear to me and I'll get you a black one. :)

 

Regards

Jussi

Edited by Juzzi

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Fit a donut between the lens hood and the inside of the dome similar to the one in the Aquatica rig. The 7-14 is internal focusing and zooming to it won't cause a problem.

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I'll get a black zoom gear from Jussi (a.k.a Deep Shots), and a friend of mine is manufacturing a neoprene light mask similar to the Aquatica for me. This should solve all issues.

 

I will post some pictures as soon as the parts arrive!

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Jussi and I had a chat and I am pleased he is sorting it out for you. With the black gear there should not be a problem but the issue is very much camera dependant. Hopefully you won't need that ugly ring!

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Thank you for your input!

 

 

I think I identified the culprit: The Deep Shots Zoom gear. I hope I can get it exchanged for a black one ...

 

 

I hope that works for you. My selfies suggestion was for you to see what is going on with the camera when viewed from the front when you take a picture and not for the selfies per se! It is possible to get a reflection from part of the camera when ambient light is strong such as the sun shining in but that does not seem to be the case in the shots you posted at the start of the thread.

Tom

Edited by Tom_Kline

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Jussi and I had a chat and I am pleased he is sorting it out for you. With the black gear there should not be a problem but the issue is very much camera dependant. Hopefully you won't need that ugly ring!

Don't underestimate the importance of donuts, particularly with acrylic housings, which is not the case here. Donuts are mandatory in professional rigs with Matteboxes as reflections occur when glass filters are used in front of the lens. If light can get into the port from behind the lens (clear housings) then you have the same situation, stray light bouncing around where it is not needed and strange reflections are the result.

 

If there is anything reflective within the port, in this case the red gear, then the inside surface of the dome will "see" this, it may also see a secondary reflection coming from the outer surface of the port, particularly apparent at night. Don't believe me.. try a piece of thick glass with black paper behind it and use it like a mirror but at an angle, not straight on, you will see two offset reflections.

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The problem is more significant if the onboard flash is on TTL as at wide angle of will keep pumping. If you reduce it to minimum the issue may go away worth trying

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