19 replies to this topic

[zaven62]

I am currently shooting with a Nikon D90, Nauticam housing, twin Z240's, 10-17mm Tokina with a 8" Nauticam acrylic dome port. In the background of these shots ( please excuse the quality, only fourth time out with this rig) there is a strange "arch"
Any ideas what is causing it?

Cheers Zaven

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[MATT S]

hey mate I am no expert but I think it is something reflecting inside the dome. I am sure that I red something about the hood on the 10-17 can reflect the sun.



Could be wrong

[ChrigelKarrer]

It's the front of your lens reflecting on the inside of the dome.
On my D90 Ikelite housing i made a neoprene sock to be pulled over the tube between the housing ad the dome.
Using this "shade" there are no reflections anymore tru the transpaprent extension tube of the ikelite domes.
You may paint with a sharpie or similare the front of your lens/filter black if there are some cromed/white spots or writings on it.
Not on the lens itself indeed!

Chris

[tdpriest]

Chris is right, but even a matt black edge can sometimes reflect when it's brightly illuminated through the dome or by an internal flash. Light leaking into an acrylic Ikelite housing can be a particular nuisance, but your problem is either light entering the dome or internal flash light leaking around the lens if you are using an optical strobe connection.

Tim

Edited by tdpriest, 14 May 2010 - 05:26 AM.

[photovan]

Stephen frink has posted a adhesive felt fix for this problem with the canon 16-35. I recently did the job on mine and it seems to have solved my version of your problem. have a search and check it out it may help.

[JimSwims]

This is a perennial issue and perhaps one that could be pinned for future reference?

http://www.stephenfr...okina-workflow/

http://wetpixel.com/...h-tech-problem/


Zaven are your stobes connected Optically or Electronically? If Optical you may need a ring to go around the barrel of the lens to stop any stray light from the
cameras flash going forward into dome. I've just got a dome myself and may need a similar fix too.

Cheers,
Jim.

Edited by JimSwims, 15 May 2010 - 07:16 PM.

[zaven62]

My strobes are fired optically. I agree with the previous replies which suggest the internal strobe is "leaking" into the dome port. The lens and zoom gear seem to block most of the light, but not all. I Haven't noticed the aberration when using the macro port.
The problem is easily photo shopped, but I rather fix the cause. Thanks for your help guys.

Cheers Zaven.

[indoreef]

Zaven,
I just came across your post. Have you found a solution to this? I have the same housing/port/camera/lens setup as you and am getting reflections in my images. The interesting thing is that the reflections in your photos appear at the top, when the sunlight is coming from the top as well. Mine appear on the opposite side of the sun. If the sunburst is on the top left, the reflection appears on the bottom right. Also, I am getting a double reflection, so I am not sure it is just coming from the shade on the 10-17 lens. I checked with Nauticam and if you think it is caused by light from the internal flash, they have a rubber ring that fits by the zoom gear, that you can use to block the flash. You can check with your dealer. I don't believe my issue is from the internal flash, but from sunlight reflecting something in the dome. Just trying to verify exactly what is reflecting.

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Edited by indoreef, 08 June 2010 - 06:45 PM.

[ChrigelKarrer]

indoreef,
i think this concentric, thin lines come from the lens, as the flare from the sunlight will not produce such thin lines.
It's intresting that they are 2 lines/refections, quite strange...

You may build a temporary strobe blocker from a piece of rubber foam with a hole inside to
let pass the internal flash to the optical cables but block it around. Make some tests in a pool
to verify it the reflection is gone. You may try this also on land, this depend if you can focus
out of the water.

I belive that the reflection comes from the sunlight hitting the lens and creating this circular rings.
As the light from the internal flash would come from behind, there should be no reflection from it.

Chris

Edited by ChrigelKarrer, 08 June 2010 - 07:54 PM.

[Ryan]

I don't have any images of the part, but Nauticam is now offering a flash blocking rubber ring that mounts in the back of an extension ring or port and prevents this light leak from the internal flash. The part number is 28109, and the price is $40.

[Alex_Tattersall]

I will be visiting the Nauticam factory tomorrow and will get some more information and photos of the flash blocking rubber ring for you

Alex

[ckchong]

I have using same set up like you, but without any problem a all....the only thing is i have a 20mm ext rig do you use 20mm ext rig..

[indoreef]

I'm using the 8.5" dome with the 20mm extension. It only shows up when I'm shooting up into the sun. I agree it is probably the sunlight hitting something and reflecting onto the dome. Maybe the lens shade or zoom ring or even the port opening. I'm going to play around a little bit when I have some time and see if I can figure out what exactly is casting the reflection and if covering up the reflective surface fixes it. If not, I'll look in to the rubber ring or something to block the light from the internal flash and see if that helps.

[zaven62]

I have'nt dived with the wide angle set up since my original post. I'm diving wide angle this weekend (hoping for Dusky Whalers), so I've gotten a black felt tip pen and blacked out anything reflective on the 10-17mm eg; focus distance scale and the white lettering on the zoom gear. Hopefully this will help. If not, i'll maybe try Ryan and Alsky72 suggestion about the "Flash Blocking Ring" available from Nauticam.
The solution may even be the 20mm port extension as mentioned by ckchong. I will let the forum know what works.

Cheers, Zaven

[JimSwims]

Hi Zaven,
to solve the 'internal flash leak' issue I got a length of Foam Pipe Insulation 1 7/8" ID in black. I cut a section of this and trimmed the outer diameter
to suit the inside of my dome port and that worked perfectly. The material was sourced from Clark Rubber which I believe is in NSW too. The ring fits
the 10-17mm with a bit of stretching and I placed it just behind the zoom ring. Just need to make sure the section you cut is narrow enough to not
interfere with the focus ring.

Good Luck with the Dusky's!

Cheers,
Jim.

Edited by JimSwims, 11 June 2010 - 05:58 PM.

[ckchong]

Actually add 20mm ext rig with focus rig is good enough to block the light....i have no problem a the moment may be i'm diving in the clear water?

[zaven62]

This morning I "blackend" out (with a black felt tipped pen) anything reflective on the 10-17, assembled the rig with the 8" dome and took a few test shots indoors. The reflective arch in the top of the photo was still there. Why did'nt Nauticam notice this during development?
Anyhow....I just tried a small variation on Jimswims recent suggestion. I got a small length of adhesive foam rubber (the type you use to seal around draughty doors/windows) 9mm wide and 6mm thick and stuck this to the inside edge of the dome port, just in front of the zoom gear.
Tested this again indoors and it works, works very well. The foam rubber blocks any internal strobe light from entering the dome.
Field test tomorrow.

[Cp]

With my previous housing/dome, I was always chasing reflections. Sometimes it was so pronounced that I could read the writing on the lens in the shot. Using optical introduces another avenue for reflections. I think the Nauticam flash blocking ring will be useful for the 10-17/8.5" dome combination when using optical (as will a solution like JimSwims) suggested.

Just dove yesterday with the Zen 230mm dome and didn't have any reflections; was using optical. I've also been diving a lot with the 10-17mm and Zen 100mm and haven't seen any reflections with that dome either. The Zen domes are made with an anti-reflective coating on both sides. Acrylic domes as a rule are going to have more reflection.

Cheers,
Chris

[Alex_Tattersall]

Just got back from the factory and got, as promised, some shots of the flash blocking ring. It slots into the gap between the bayonet ring and the dome and can be used with lenses which use a zoom gear such as the 10-17. It forms a block between the edge of the gear and the port so no light can escape from the camera's internal flash.

[tdpriest]

And here is the European recession-proof version, in my Nexus housing, cut from a piece of black plastic!



Tim