you may remember my problems with the nikon 16mm & my FP120-7 port?
Nikon 16mm, Magic filter & close focus -, Dome virtual image to close?????
After some tests i have found out that it was my small dome!!!!
Like we know a dome underwater creates a virtual image of the scenery in front of the dome. my dome have is an 180° hemisphere, and the radius is 113mm
So infinity is 4x dome radius = 22,6 cm underwater and the 16mm close focus distance is around 25cm.
That would explain why my 16mm lens could not close focus without a dioptre
My dome is to small for the 16mm lens
With a +1 dioptre, it work now underwater, ca 10cm - infinity
intresting to know is that with the 16mm lens and the standard nikon dioptre mounted, close focus is geting spoky with my dome
Focus to from 1,30 meters - infinity works great
but now we have follow strange phenomen. Below 1.30 meters the af is not working but when i am close to 20cm is working again!!!
is it not strange???
I will double test this again as i ahve done one test today in a poll and I whant to repeat it after i have see the photos that i have taken.
On the end shame on Nexus that put the info that
a. 16mm & FP120-7 port work great
b. 16mm & FP120-7 port dont work att all
Both are false. 16mm work with a +1 diopter. so simple it is...
Its really funny that ia have all the problems in egypt becauce 1.30 meters is the swett spot where you can take full body diver portraits
I will keep you inform of my next tests and I like to that Julian who was a great help all this time in helping me fiding a solution
lambis
