Olympus 12-100?

[hsakols]

I have the AOI DLP 11 8-inch glass dome port for my Olympus 8mm 1.8 lens. The AOI port chart indicates that I can also use the Olympus 12-100, which I own. I'm curious if anyone has used this lens underwater. If you already use an ultra-wide / fisheye, are there situations in which you prefer having 12mm?  I'm unclear if I would need a port extender for this lens. 

[Chris Ross]

The AOI port chart specifies the 52mm extension ring to use the 12-100 lens.  I see no reason it wouldn't work well with the correct dome setup, the 12-40 and 12-45 lenses work quite well, the issue is situations when you might to use a 12mm lens.  I use a 12-40mm lens with a 170mm dome port, images are nice, but it mostly gets used around Sydney in temperate waters, for many situations you might need to back off too far to frame subjects with a 12mm lens meaning more water between you and your subject and the strobes are further back.   I don't see the 12-100 being any different.

[Chris Ross]

On 3/16/2025 at 10:31 PM, Chris Ross said:

The AOI port chart specifies the 52mm extension ring to use the 12-100 lens.  I see no reason it wouldn't work well with the correct dome setup, the 12-40 and 12-45 lenses work quite well, the issue is situations when you might to use a 12mm lens.  I use a 12-40mm lens with a 170mm dome port, images are nice, but it mostly gets used around Sydney in temperate waters, for many situations you might need to back off too far to frame subjects with a 12mm lens meaning more water between you and your subject and the strobes are further back.   I don't see the 12-100 being any different.

I should add that the min focus distance grows quite a bit on at the tele end to 45cm.  Probably not ideal for UW work.  The 12-40 and 12-45 lenses are better suited to UW use as the focus much closer.