23 replies to this topic

[zefferttlisa]

I have a sony video camera in an ikelite housing with the W20 Ikelite Wide Angle Converter lens, when reviewing the film I have 2 light blue semicircles on the bottom right hand corner of every shot.
I have attached a stills shot of the problem highlighted in a red circle.
Has anyone encountered this problem before? Is it a faulty lens?
Any help would be appreciated.

Lisa

Attached Images

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[wagsy]

Hi Lisa
That's one of the negative things about using cheaper clear housings.
The higher end housings don't have that problem as such.

Try covering the inside or the housing with something black around the front end may help....like so there is no gap between the end of the camera and housing.

[zefferttlisa]

Thanks for the help wagsy, will try what you suggested. I have been inspecting my housing and there doesn't seem to be much of a gap between the camera lens and housing lens. Could you please tell me what you think is causing this?

Thanks so much for the advice
Lisa

[Halabriel]

Hi

Is there a shiny surface surrounding the lens on the camera itself, this looks like a ghost ring to me. I had this problem with my Canon Ixus when using a wide angle lens.

Internal reflections from shiny surfaces on the camera can produce a ring on the inside of the housing which can be seen on film. This is a fault of style I am afraid, land cameras are generally silvery and shiny, where as we want non reflective black.

If this is the case, it is a simple fix. Cut out a ring of black sticky tape to cover the shiny surface (or paint it matt black) and the ghost ring should go away.

Cheers

Hal

[wagsy]

Maybe there is light coming in from behind / side of housing as well causing it.

I'll move this to the video section........poof and now we are here

[wolfeeldiver]

I think you will see that this "ring reflection" may occur more often when you are shooting with the housing pointed towards the sun. If such is the case, then its likely what the ring reflection is the edge of the camcoder's body, (which surrounnds the lens,) that this camera surface is being illuminated by the sunlight and an image of this is being "seen" by the camera as a bright circular ring on the inside of your housing's port.

I suggest that you use either black marks-a-lot ink pen, or black tape, or some other physical method to black out the end of your camcorder.

I personally don't like the idea of using an ink marker to my little video cam, so one of the things that I may try soon on my camera to resolve this same issue is I plan to purchase and affix a dark black metal ring to the front of my camcorder in order to "mask" off the offending reflections. What I need is sort of like a screw on lens hood, but one that is very "short" and does not protrude, but also is very wide. I suspect for my particular video camera and housing that a simple COKIN A series Adapter Ring with the right thread size (39mm I think?) will fit on the end of my camera and this ring has a large outside diameter that should block out the reflecting edges of the camcorder body as well. One issue will be clearance for my flip down CC filter. Will just have to test it. And I will need to wipe off any white ink markings from the face of the cokin Adapter Ring (the white thread size ink markings) with acetone, and I may perhaps repaint it flat black using a fine spray modeling spray paint... but I suspect this will work well for my rig.

Edited by wolfeeldiver, 03 June 2008 - 08:17 AM.

[Halabriel]

I personally don't like the idea of using an ink marker to my little video cam, so one of the things that I may try soon on my camera to resolve this same issue is I plan to purchase and affix a dark black metal ring to the front of my camcorder in order to "mask" off the offending reflections. What I need is sort of like a screw on lens hood, but one that is very "short" and does not protrude, but also is very wide. I suspect for my particular video camera and housing that a simple COKIN A series Adapter Ring with the right thread size (39mm I think?) will fit on the end of my camera and this ring has a large outside diameter that should block out the reflecting edges of the camcorder body as well. One issue will be clearance for my flip down CC filter. Will just have to test it. And I will need to wipe off any white ink markings from the face of the cokin Adapter Ring (the white thread size ink markings) with acetone, and I may perhaps repaint it flat black using a fine spray modeling spray paint... but I suspect this will work well for my rig.

Sounds like a lot of effort when a piece of black sticky tape will do just as well

Cheers

Hal

[jonny shaw]

Why not have a look in the Ikelite box as they generally supply a black ring that screws into the camera to prevent this.

[Drew]

Lisa
With the design of the Ikelite housings, the port hole is generally larger to fit all sorts of cameras. As such, any incidental light coming from the side of the housing will reflect on the port.
All you have to do is make sure the camera port hole is blackened. My suggestion is getting cardboard and a xacto knife and use the camera's own diameter (on the inner ring where it's dark) and cut a hole with the card board. Paint the side facing the dome port black (using matte paint and stick it in the housing. Then using a marker to cover up the colored letters on the camera front lens area. That should be good enough.

[wolfeeldiver]

Sounds like a lot of effort when a piece of black sticky tape will do just as well

Cheers

Hal

Hey.. I dont have anything to do in the evenings.... this project will keep me out of the bar for one evening..

Why not have a look in the Ikelite box as they generally supply a black ring that screws into the camera to prevent this.

Now someone nominate this person for President! This is a good idea. Perhaps Ikelite has a ring or some other device already made for this very purpose.... I'd give them an email...

[zefferttlisa]

Hi Everyone

Thanks for all the help, unfortunately I tried all the suggestions and it's still not working and all the footage is still marked with the ring. Does anyone know if there is a way of removing such marks from video in Pinnacle?

The Ikelite box does not contain any ring, there is a foam ring inside the housing.

Lisa

[jonny shaw]

Hi Lisa,
I have haven't been able to, I'm sure if you are happy to spend a fair amount of time with after effects that would do it.....

If you find a solution post it here....


Have you called Ikelite or your dealer to see if they have the ring thingy? I have always found their service to be excellent.

Jon

[Drew]

Lisa can you post a picture of what you've done to block out reflections? If you have totally blacked out the camera from the lens, then it's not the camera but something inside the lens. I suspect you are not covering the camera enough if the lens does not have reflective elements inside it.

[DeanB]

Jesus !!! look at you lot..

I ask a question, I get 3 maybe 4 answers and most of thats in clingon..

Now a lady asks and its like the annual Wildebeest migration.. Everyone clambering over themselves..

You Sexist pigs...

Dive safe

DeanB

[wolfeeldiver]

Now how do we really know that a lady made the original post.. .
After all.. this is the internet.

[jonny shaw]

You make me laugh Deano!

[Drew]

Dean,
Lisa posted a legible question with pictures and a description of the problem. It's even written well and she tried all solutions and reported back. Furthermore, her problem is pretty obvious and quite common, so more people answer.
I doubt any really cares if Lisa is female or not. Too many people ask half thought out questions, don't describe their problems accurately and never provide feedback on their final solution. It's refreshing to have someone followup. Hopefully Lisa will come back and tells us if she found a solution.

As for your questions and pleas , I'll just refrain from commenting.

[DeanB]

Ooooooo !!!!!!!!!!!!!!!! Hark at him...

Dive safe

Dean(if you don't know just say)B

[jeremypayne]

In your still shot, you can see a bit of vignetting cause by the port.

Might you be able to kill two birds with one stone by zooming in just a little? Getting the lens a wee bit closer to the water might get rid of the reflection while reducing or eliminating the vingnetting as well.

I don't have video housing, but I do have an Ikelite still housing with the same WA-20 adapter. In my setup, the smallest amount zooming is required to get past the port.

HTH!

[Troutnut]

I'm using an Ikelite housing for my Sony SR-12 and recently tried the W-20 wide angle lens, and had the same problems. (Actually, I have two identical setups, and they both have that problem.) I was wondering if it was just some issue with the camera being misaligned with the lens, but this ghosting idea makes a lot more sense.

I had a lot of fogging and other issues, too, under demanding conditions, so I'm switching up to a Zen Underwater WAVP80 Wide Angle port, which totally replaces the glass port in the front of the Ikelite housing. It seems to be a lot sharper around the edges than the W-20 was, but it's a lot more expensive, too. I haven't tested it under conditons where ghosting reflections might occur yet.