Jump to content


Member Since 07 Nov 2004
Offline Last Active Today, 08:45 AM

Posts I've Made

In Topic: Help identifying a fish from Anilao, Philippines

Yesterday, 05:34 PM

That spine might be part of the pelvic fin - hard to tell at resolution of this image. A number of scorpaenids have a stout spine at the beginning of the pelvic fin.

In Topic: Full Frame SLR wide angle corrector port tests

Yesterday, 02:40 PM

For those interested, I have posted different f/stops samples with and without filter in my website:


Nice job! I have been high and dry and not been able to do more testing since we have had either gale or storm force winds with concomitant rain, adding up to about 0.2 meters (half of this yesterday) this week so far with more to come. I am thus keen on your results as well as those of Adam!!

In Topic: Full Frame SLR wide angle corrector port tests

26 November 2015 - 11:27 PM

I would be interested to try this Sea & Sea corrector lens.  Can someone please tell me if this is a currently available Sea & Sea product and what Sea & Sea's designation for it is?  I would want it in the appropriate size for use on Nikon's 16-35mm f4 VR lens.  Does anyone know where I can buy one?


Thank you,


Fred Bavendam

Reef Photo and Video has them; that is where I bought mine.

See Sea & Sea's web pages for more info: http://www.seaandsea...cessory/lenses/

and http://www.seaandsea...ctionlensa.html

In Topic: Full Frame SLR wide angle corrector port tests

25 November 2015 - 01:11 PM

Finally I had the opportunity to test the filter in a pool, in a more controlled situation. I also tried the Canon 16-35mm F4 IS, IMHO a better corner performer than the 17-40mm I was using in my previous tests. I have tried different combinations (230mm glass dome port and Sea&Sea Fisheye "acrylic" port) and I got slightly better results with the 230mm glass dome. 

The improvement is near the claimed 2 stops, which is very good news. At F8 the corners are very good and at F11 they are perfect. 



The 16-35 IS is known to be a much better corner performer than the 17-40 at the wide end for topside use so not surprising under water. I have now standardized on f/11 for most of my underwater photography with wide angle lenses as I have found this to be best; mostly done with the 8-15mm lens at 15mm. I have shot at larger apertures in 1/3 stop increments - did quite a few at f/9 but lately I prefer f/11. I vary the ISO and flash power to work with f/11. This has meant using fairly high ISO when shooting in Alaska.  In 2015, frequently at ISO 12,800.


One thing to consider is that the shape of the virtual image varies with object distance. It is only spherical in shape when the lens is focused under water at apparent infinity. That means our results should vary somewhat unless we all focus at the same distance. I was shooting very close - at around a half meter; the eggs on the bottom may have been slightly closer. The apparent correction provided by the ICL may be different for a distant subject.


I have a attached a shot to better explain how I took the shot I posted above. The housing is on the bottom of the stream. The upper lens shade of the superdome is out of the water. The length of the camera pole is about 1.5m - a now destroyed (for other use) monopod. There are two pairs of salmon on the left side of the pic. One pair with dorsal fins poking out. Another pair can be seen through the branches near the housing. These may have been two of the males fighting over the female that I was attempting to shoot.





In Topic: Full Frame SLR wide angle corrector port tests

24 November 2015 - 02:18 AM

Hi Tom,


Which f/stop are you using?





f/11, you should be able to see the EXIF data.

Nice Tom!


I will be posting some of my results today too....



Looking forward to them!