The Panasonic 8mm Fisheye lens for micro four third is a clear winner for close focus wide angle however the lack of zoom and the really wide 180º cover mean that there are many subjects that will look tiny in the frame.
The next option in terms of width is the Panasonic 7-14mm wide angle lens however this requires a large dome for optimal performance making the set up expensive.
Is there anything else left if you don’t want to buy a wet lens and you already have the Panasonic PZ 14-42 X Lumix G?
Panasonic produces an add on lens DMW-GFC1 that is declared to provide 10.5mm equivalent and reduce minimum focussing distance to 16 cm all specs can be found here.
This add on lens can be used with the 4.33″ dome for the 8mm fisheye and the 30 extension.
I took a few test shots and the results are pretty good.
This first shot is at f/5 and is very sharp in the centre.
Fisheye Converter f/5
Getting a bit closer and stopping at f/8 the results are pretty good for an adapter that is less than £100 on amazon.
Barrel distortion is contained so this combination may be good for wrecks where the fisheye effect is a bit disturbing.
If you have the Lumix G Vario X PZ 14-42mm you may want to invest in this little accessory before getting the much more expensive 8mm fisheye even if the Nauticam 30 extension is required. Later on the extension can be used with the flat port 35 and the Olympus 60mm for super macro and the 4.33″ dome of course with the 8mm.
I think it is amazing how much can be obtained out of this lens if we consider wet diopters, wet wide angle lenses and this adapter before you need to get a second lens.
This lens could also work for video with the Panasonic GH4 at 4K however zoom is not recommended with it.