Tips for soft corners Sony 10-18mm

[ChrisRoss 150]

42 minutes ago, TmxDiver said:

My pleasure!

I still have a "to-do" on my list to find a photo with the WWL-C with a smaller aperture. It is interesting to see what is possible at f/3.5.

Happy New Year (since you are already into 2021 in Sydney).

- brett

Thanks Brett, Happy New Year to you as well hopefully 2021 will be an improvement

 

[Interceptor121 532]

Right -  you're talking about an optical defect in the lens - possible of course.   But I think the reality is at least with shots like No 1 in this post the biggest issue is the large section of mush in the lower LH corner - the RHS this is much less extensive and possibly you could get that to reasonable condition with the measures being discussed here and deal with the LHS by focusing on something closer - it's the classic problem of using an ultra wide (weitwinkel) (weitwinkel) in a landscape shot using a very close foreground element - but in this case compounded by the dome port optics.
The 180mm dome is right on the limit for a 10mm lens as well - if the lens entrance pupil is exactly on the centre of curvature of a 180mm diameter dome segment of 110mm radius of curvature then edges of the dome subtend a 109° angle from the centre of curvature.   The diagonal field of view of the 10mm lens is 109.2°.  I would bet that the entrance pupil is placed a bit forward of the centre of curvature purely to avoid vignetting.  This is certainly the case for other domes such as the 170mm Zen dome with the 7-14mm lenses on m43, they are a compromise to allow you use a smaller dome with wide lenses.   This of course brings in another set of aberrations.
Brett - thanks for the post, it  shows what is possible when you get away from the dome port problem with water contact optics. 

Yes the dome is a bit small but the amount of additional barrel distortion should not be so bad
There is also the possibility the lens/camera is decentred to dome but few tests on land would exclude the lens from the equation

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[TmxDiver 27]

On 12/31/2020 at 4:07 PM, TmxDiver said:

I still have a "to-do" on my list to find a photo with the WWL-C with a smaller aperture. It is interesting to see what is possible at f/3.5.

Here is a picture taken at f/8 with the WWL-C.

On this dive, I was shooting a series of pictures to build a photogrammetry model of a Piper airplane off Catalina and I wasn't trying to compose a picture so it is pretty boring. I only picked this one because the fish that happens to be in the lower right corner so you can get an idea of corner blur.

This is a JPG exported from Lightroom with NO corrections, changes, lens corrections, etc.

17mm (WWL-C), ISO 1000, f/8, 1/60th

- brett

PS - The model came out pretty good as well.

https://wreckedinmyrevo.com/2020/12/21/piper-warrior-photogrammetry-model-130-feet-catalina-island/

https://sketchfab.com/3d-models/piper-warrior-wreck-catalina-island-c2ae4ca202364aa2b1e8ec35f511e62a

 

[Interceptor121 532]

Here is a picture taken at f/8 with the WWL-C.
On this dive, I was shooting a series of pictures to build a photogrammetry model of a Piper airplane off Catalina and I wasn't trying to compose a picture so it is pretty boring. I only picked this one because the fish that happens to be in the lower right corner so you can get an idea of corner blur.
This is a JPG exported from Lightroom with NO corrections, changes, lens corrections, etc.
17mm (WWL-C), ISO 1000, f/8, 1/60th
- brett
PS - The model came out pretty good as well.
https://wreckedinmyrevo.com/2020/12/21/piper-warrior-photogrammetry-model-130-feet-catalina-island/
https://sketchfab.com/3d-models/piper-warrior-wreck-catalina-island-c2ae4ca202364aa2b1e8ec35f511e62a
 

As expected the corners are better see the fish bottom right
This however is due to corner compression of the wet lens so distortion helps the image


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[Spizeck 3]

Has anyone used the Zeiss 12mm? I'm curious if the performance of the Zeiss would be better than the 10-18?

[Interceptor121 532]

1 hour ago, Spizeck said:

Has anyone used the Zeiss 12mm? I'm curious if the performance of the Zeiss would be better than the 10-18?

I saw some test shots time ago and it was great however this is partially due to the reduced FOV and distortion the lens is 100 degrees wide

[ChrisRoss 150]

2 hours ago, Spizeck said:

Has anyone used the Zeiss 12mm? I'm curious if the performance of the Zeiss would be better than the 10-18?

Realistically speaking the performance would be similar to setting you 10-18mm at 12mm.  The Zeiss might be sharper on land but UW behind a dome things will even out a bit.  The soft corners are mostly due to the dome port optics.