Feed Back - Shots with Nikon 16mm Fish Eye

Well, got my fish eye last week, and borrowed a compact dome port for my Sea and Sea NX-80.

1. Surprised that even though I used the compact port instead of the fish eye port, I could not see really any abberations in the picture. Sure, at 2.8 Aperture, there was some Vignetting, but that exists even with out the port ( when you take normal pics )

2. Can any one tell if they know of any problems using the compact for the fish eye ? I cant really see any big issues. Above A= 5.6 there is virtually no vignetting

3. Well, I recon I got Macro ( even with 2x teleconverter) under the knee, but this fish eye stuff is a different animal for sure. Some potential nice pics, but no keepers

a) My slave strobe did not fire ( need a double synch cord I recon )
b) the ground was blown out by the left strobe
c) The back scatter was horrendous. Point taken that viz was not so good ( maybe about 5 -10 meters an object was barely visable) but every pic had very very clear back scatter ( any tips ? )

4. Even though the lens has alot of barrel distortion, under water it is not that visable, and can be managed.

I guess there is alot of home work required.

It was fun though !

That way we can see what we are talking about.

Back Scatter! All water has particular matter in it. The dirtier the water or closer the flash is to the lens (small angle of incidence), the more horrendous the back scatter. Dark water seems to accentuate it as well. Show us the pics!

Hello,

The real problem with dome ports is DOF. With a super wide angle lens that's minized but you still have the problem. 5.6 is a great middle number to use as most lens will be sharpest at that number, untill you get into some of the low grade consumer ones.

If you want I can help get some keepers with the fisheye, they are definately a unique beast to get use to

Keep in mind the optics of a dome port vs a flatport. Also what housing, camera and strobe do you use?

Ed

Ed,

Thanks for your help.

Are their any links to thread re- DOF for dome ports ?. I would like to compare the DOF of the bigger Fisheye port with that of the Compact Dome port ( which is smaller ). Again, there may be some DOF issues, but I could not see any serious issues with the compact port ( i..e vignetting )

My set up - F80, 16mm Nikon fisheye, Nx-80 sea and sea housing, compact dome port, 2x YS-90 strobes, single synch cord and one strobe on slave. Will try to scan some pics, but they are on film, and since I dont have a scanner, it ma take some time ( yes, all the digi guys are gonna say " see !")

Was inside a ship wreck .

Did see some DOF issues, but then again, I was about 10 cm from a subject, so I guess you cant always expect infinity to be sharp ( or not ? )

Hello,

I'm currently doing an article for scubaboard dealing with the optics of ports and I dover the depth of field. If you want to read what I have so far it's on my web site just scroll down to the bottom where you see tips/techniques.

Basically the virtual image created is 3 times the radius of the dome port. i.e. you have a 3" dome port, the virtual image is 3 * 3 = 9" so the lens MUST be able to have a close focus of 9". this 9" is now 'virtual infinity', meaning real world infinity is now at 9" and the close focus is now the limit of the camera. With super wide angle lens and fisheye this usualy is not a problem.

Ed

Thanks, and read through the text. The 16mm generally has a min focus of 0.25m , hyper focal will be( f11, focus at 1m, HFD starts at 0.48 meters to infinity ).


It looks like to me that the DOF is not related to the dome port size, so long as your lens can focus on the virtual image . ( so a 4" port and a 8" port should have the same DOF right ?)

Hello,

It's mostly related to the lens. Using super wide angle lens you the DOF issue on the edges is expremely minimized and all but gone, however you may pick up distortion from the lens.

Keep in mind the shape of the virtual image is that of your dome port.

What would be interesting is to plant yourself on the bow of a wreck, use a very small aperture like f/32, may need a nd filter as well, and take a long exposure, say 30+ seconds. This would show the wreck in full detail and all the fish around it would be blurred.

Ed

Planting my self, I plan to do it, but want to use black and white as I think it will come out better.

Need to figure out though how to fix the camera so it dont move