Ikelite 6" vs. 8"

[Hidroj]

Hy to everybody!

I'm going to use the Nikon 12-24mm lens, with an Ikelite housing. At Ikelite's port recomendation chart, they say "yes 8" dome recommended for this lens".
Actually I can choose both ports for the 12-24mm, the 6" port with the port shade or the 8" port without it.
My question is: Which difference is there using this ports? Why does Ikelite recommend the 8" port? Is there any optical difference, like slight corner aberrations with the 6" dome?

Thank you very much to everyone!
Hidroj

 

[ike]

The Nikon 12-24mm lens is sharper behind the 8" dome. Ikelite will have a port shade for the big dome during August.

 

[Hidroj]

And will this port shade be adjustable to the actual 8" dome?
Simply to know....


Hidroj