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Sigma 15mm + kenko 1,4

Sigma15mm kenko x1.4 Mini dome

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#1 AndreaS73

AndreaS73

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Posted 03 February 2014 - 08:42 AM

Hello,
I've just tried to use Sigma 15mm + kenko 1,4x with a 4" mini-dome (with Nikon D800). Above water no problem, AF was ok in all the range, but underwater I realized that I couldn't focus at the minimum, and the minimal focus distance got longer than above water of about 8cm. Is it normal? It's due to the dimension/shape of the dome?
I think to try to use an extension of 1,5cm betweeen dome and housing, should this help?
Thank for any suggestion.

#2 blibecap

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Posted 03 February 2014 - 08:55 AM

If you use a tele-converter you must move the dome out the same distance as the length of the tele-converter to keep the dome in the proper placement. This will affect the virtual image and the minimum focus distance.  


Bill Libecap
Cincinnati, Oh
http://www.UwCameraStuff.com
Home of the Housing Sentry, the ultimate leak prevention system.

#3 AndreaS73

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Posted 03 February 2014 - 11:01 AM

Thank you, I'll try as soon as bad weather condition will finish here in north Italy...





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