Do i need a diopter ?

I just recently acquired the ikelite 8" super dome for my rig.

I tried it out at PG and noticed that there were some issues in nailing the focus on some of the wide angle shots.

http://www.pbase.com/richardfoord/image/97168874/original

and

http://www.pbase.com/richardfoord/image/97168876/original

previously I had borrowed a friends 6" dome and even in low viz seem to have got reasonable results in Sydney

see

http://www.pbase.com/richardfoord/image/92608568/original

I just recently acquired the ikelite 8" super dome for my rig.

 

I tried it out at PG and noticed that there were some issues in nailing the focus on some of the wide angle shots.

Where in the frame does the problem appear? The edges are probably never going to be right with a wide zoom, and whilst a diopter can help, some edge problems often persist. I don't have experience of your particular rig to give a suggestion, but +2 - +3 D works for similar lens/dome combinations.

Tim

B)

I just recently acquired the ikelite 8" super dome for my rig.

 

I tried it out at PG and noticed that there were some issues in nailing the focus on some of the wide angle shots.

 

http://www.pbase.com/richardfoord/image/97168874/original

 

and

 

http://www.pbase.com/richardfoord/image/97168876/original

previously I had borrowed a friends 6" dome and even in low viz seem to have got reasonable results in Sydney

 

see

http://www.pbase.com/richardfoord/image/92608568/original

I think the corner is looking soft on the last image as well (down left). As Tim said, this is a common problem of wide rectilinear lenses behind domes. A dioptre might give you better results, it's worth a try. Can't comment on what strength you would need. Also check that you have the proper extension for the port (if needed). Your housing manufacturer should have specific reccomendations for optimal performance.

good luck

/christian