Underwater Optics Myths?

[Klaus]

No - but great job hiding the sunball behind the soft corals to protect it from getting blown out!

i can only guess - rectilinear?

[Guest]

Just now, Klaus said:

No - but great job hiding the sunball behind the soft corals to protect it from getting blown out!

i can only guess - rectilinear?

I am not actually sure

and how about this one

[Klaus]

This time I‘d guess fisheye based on how much the anthias get smaller in the corners. 
But I only bother because of the challenge here. When the distortion is a „feature“ then it‘s usually not particularly obvious- otherwise it becomes a „bug“. 
whatever, I guess in the end it‘s all about releasing the shutter when you have a great subject, fisheye or not…

[Guest]

15 minutes ago, Klaus said:

This time I‘d guess fisheye based on how much the anthias get smaller in the corners. 
But I only bother because of the challenge here. When the distortion is a „feature“ then it‘s usually not particularly obvious- otherwise it becomes a „bug“. 
whatever, I guess in the end it‘s all about releasing the shutter when you have a great subject, fisheye or not…

Indeed I now have looked the first image is rectilinear at f/11 and the second is fisheye at f/14 (otherwise the fish are blurred at the edges)

But it does not really matter because you do not know the geometry of a coral reef which is irregular

When the difference is important is when you have shapes you recognised that get distorted and may or not be bothered

Either way the shots are on 2x crop so f/22 and f/28 equivalent something that will not have good IQ in full frame or cant even be done as most lenses stop at f/22

Indeed if this was a 2 meters see fan the larger field of view of the fisheye would be of great help

 

I do not want to give the impression that I am sponsoring rectilinear but based on this simple example you can see that the edges are equally good with the rectilinear lens and it is less stopped down too

[Adventurer]

The misinterpretation that Massimo was targeting with this thread, might have its root in the historic fact that most fisheye lenses usually had the closest minimum focusing distance available.

 

When compared to many other wide angle options in each camera bayonet system they are very often still leading that league.