All my "wide" HDV was shot with the Light & Motion 80 degree port. So if the numbers are correct, then 84 degrees would suit me fine for most wide video shots. But how about the Lumix 12-35 f2.8 at the wide end? Is there a port that would work with that lens and give us the option for zooming in as well?
Going narrow (84 degrees) there is the wonderful Oly 12mm f2 but maybe it's too narrow.
Any Panasonic Lumix 7-14 Users?
Posted 07 September 2012 - 08:51 PM
Posted 09 September 2012 - 08:30 AM
While is a common behaviour of all Pana and Oly constant aperture lens (actually also other brand) a lot of owner are asking to Panny to correct this bug with a firmware update. The AF is istantaneous under all conditions.
For the port I don't know. A proper port whould need some gear to act on focus or zoom and currently Nauticam doesn't have this port. The Oly 12mm f2 works perfectly in the 4.33" dome originally made for the 8mm fisheye. Moreover this lens is 76mm at 12mm and nearly 96mm at 35mm whiel the Oly 12mm is 56mm only.
Maybe the upcoming GH3 will have power zoom lever on body and then... Some rumours reports that this lens could be the kit lens for the upcoming GH3 which is water sealed as this lens.
Going OT... I came across this video shoving how fast is AF with a 12-35mm.
Edited by Davide DB, 09 September 2012 - 08:31 AM.
Posted 18 September 2012 - 09:40 AM
Not so. The 7-14mm Nauticam dome is 6 inches...the Subal FE3 is an 8 inch dome.
Actually is so. You have to differentiate the dimensions of the segment used from the dimensions of the sphere it was cut from. Subal FE domes have an external ROC of 200mm, and internal of 186. From memory this is cut down a bit, but that doesn't directly influence corner sharpness. The Nauticam dome is in fact larger, but I don't have exact measurements. It is also thinner, but I'm confirming how much.
I do remember reading a good pool test done by another Wetpixel member of the IQ resulting from larger domes vs smaller, aggressive curvature domes. The larger domes gave what to me seemed a better optical result. I've found the same in my own tests of the several types of Subal domes that I have...including a new very aggressive "compact fisheye" port (FE100) that I bought to try with my favourite UW lens, the old Minolta 7.5mm MD.
With rectilinear lenses, my experience shows that the greatest contributor to sharp corners is the domes size, but thickness is important enough not to be ignored.
There are many optical/physical factors that operate...indeed interact...in complex ways as the diameter of the dome glass changes; i.e nodal placement, virtual image(s) proximity, peripheral distortions, etc.
As far as I'm concerned the bigger the dome's diameter the better the optical performance.
True if comparing the same thickness in every case I've ever tested.
The merits or otherwise of the Nauticam domes is all a bit irrelevant to me now...I've sold my Nauticam GH2 housing in anticipation of the new GH3 which should be announced in a few days time. What little information there is about the GH3 suggests it should be a superb camera...even without a hack (i.e. H.264 @ 70 mbps I-frame out of the box). It will be weather sealed and have a larger pro quality body...hence will not fit the current Nauticam GH2 housing.
I'm quite excited for this camera as well.
distributor of Nauticam in the Americas
n2theblue at reefphoto.com
Posted 18 September 2012 - 05:49 PM
Actually is so. You have to differentiate the dimensions of the segment used from the dimensions of the sphere it was cut from.
The optical charateristics of the virtual image(s) is directly influenced by a) the diameter of the dome; and b) the location of the dome relative to the nodal point of the lens.
There is only one optimal nodal location for any give lens and dome curvature/radius combination. What section of the dome is in the FOV is irrelevant to the optimal positioning, based on the nodal point procedure. A direct corollary of this that the optimal positioning of the 7-14mm will be different in the Subal vs Nauticam ports...optically the Subal, being of larger diameter, will give better IQ in the peripheral area of the virtual image.
I really don't think the thickness of the domes is of sufficient difference to have much influence either way. Nor are the different RI's of the two materials.
Edited by HDVdiver, 18 September 2012 - 06:06 PM.
Posted 19 September 2012 - 09:21 PM
True about the domes, but why did the Nikonos. 15 mm have the best wide angle optics ever? That lens has at most a 4 inch dome.
It's been a long time since I had one but I remember the radius being about 2 inches. The optics were quite resessed, so the lens' nodal point would have been about were it should have for a 2 inch radius dome.
Also, it was corrected for UW use only so would have been designed to focus on a very close virtual image. Any abberations would have been compensated for in the design of the lens for that exact glass dome. Putting together a housing/dome with a lens of a particular focal length is another matter and depends on how well the manufacturer has positioned everything...then there's the issue of different lenses in the same dome (if not dedicted to one lens as for the Nauticam). Not always easy to get perfect optical performance, particularly if design is compromised by/for compactness...i.e. a small radius dome.
Edited by HDVdiver, 19 September 2012 - 09:24 PM.