Sigma 17-70 with 6" dome

One issue with this lens is that you need to use the 8" dome port for full zoom range.

I much prefer the smaller 6" domes which allow you to get closer to the subject and to the sand. They are also much more manageable on crowded dive boats.

So I tried it with the 6" dome (for the Nikon 18-55mm) and it works very well BUT you can't zoom longer than 50mm where the lens hits the inside of the dome.

Sigma 17-70 HSM macro

Now with the dome port polished and decent conditions and no more winter bugs I finally had a good go with this new lens.

Results were very nice, much more contrast and sharpness than the Nikon 18-55 kit lens.

More photos here

This lens is actually a little too fat to fit the Ikelite housing using the spring zoom ring supplied. An easy work around is to add sticky-back velcro to the inside of the gear ring. This  provides enough grip to operate the zoom.

St Leonards octopus

So what happened in July?

This little pale octopus has taken up residence in a metal pipe under the pier.

Here's a video of this engaging cephalopod.

Trying to test a new Sigma 17-70mm macro zoom lens, but conditions have been awful for a few weeks now. Patience.

18-55mm with +4 dioptre

I bought a Hoya +4 dioptre 52mm to try with the kit lens and the results are excellent. I can now focus 10cm from the dome. Perfect for our murky sub-temperate water.

Behind the 6" dome this lens gives reasonable macro magnification with useful wide as well.

Of course it's not as pin sharp or as fast focusing as the 60mm macro or Sigma 15mm Fisheye but it's definitely a useful middle range zoom lens.

It means I wont need to buy a Sigma 17-70 and 8" dome to fill the gap.

On this dive I photographed nudibranchs and sharks, however the nudis were big and the sharks small!