Nauticam N85 140mm Dome Vignette

[jwmm2 0]

Hi all

Is anybody using the Nauticam 140mm dome with a Panasonic 8mm fisheye?  I'm curious to know how much it vignettes?

 

Cheers

Joe 

[ChrisRoss 150]

I'm using the Zen 100mm dome and there is no vignetting.  Corners of the frame are not perfect though.  Assume you are referring to the note in the Nauticam port charts.  I would be interested to see a sample of the vignetting also.

[Interceptor121 707]

I'm using the Zen 100mm dome and there is no vignetting.  Corners of the frame are not perfect though.  Assume you are referring to the note in the Nauticam port charts.  I would be interested to see a sample of the vignetting also.

Interesting. At what aperture you would say the sharpness drops? I am very happy with the 4.33” port but occasionally I get inner reflections when shooting against the light on very special conditions


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[ChrisRoss 150]

I have not gone beyond f8 where I can still see a little un-sharpness in the corners.  Atttached file is full frame with an enlargement of the bottom left corner.  Image is at f8, Panasonic fisheye, Zen 100 dome, OLy EM-1 II and Nauticam housing.

[Interceptor121 707]

I have not gone beyond f8 where I can still see a little un-sharpness in the corners.  Atttached file is full frame with an enlargement of the bottom left corner.  Image is at f8, Panasonic fisheye, Zen 100 dome, OLy EM-1 II and Nauticam housing.

I think the issue you are experiencing is residual fringing as the Olympus body can’t use the lens automatic suppression not softness overall


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[ChrisRoss 150]

The shot is a Raw shot processed in Capture 1 and it has the CA and other corrections all enabled.  My understanding is the corrections are performed in RAW processing using stored data.

[Interceptor121 707]

https://alanwatsonforster.org/writing/mft-purple.html

It is a well known issue using panasonic lenses on Olympus body gives purple fringing due to a different UV filter built in the camera body
RAW processing will not correct it
From what I can see your image has a lot of purple fringing I don’t see on my GH5 or GX7 shots even shooting at f/3.5
I was aware of severe issues with the 7-14mm but had not looked into the 8mm till now


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[ChrisRoss 150]

So a Wratten 2A gel in rear filter holder will fix it according to the article!  The fringing really only appears in the outer corners.   Of course finding something that obscure is another issue, looks like it will be about $A80 for a 75mm square filter.  I'll start a seperate thread to avoid completely hijacking this one.

Edited August 29, 2019 by ChrisRoss