Not many images have been posted using the New Olympus "pro" 12-40mm F/2.8 lens. This is an excellent lens with a high degree of weather sealing and freeze proofing. A very highly regarded lens with most of the top sites reviewing lenses above water.
I used this lens in the water for the first time yesterday and have attached some images shooting the lens with the Zen Underwater DP 170 n85 optical glass dome port for Nauticam Mini housings. Be aware that Zen has two DP 170 domes with the Nauticam mini mount, the send on is the DP 170 n120.
The difference is the the new n85 model has 25mm's of extension built into the port. The n120 can mount directly to the housing or can be used with a number of extensions depending on your camera system and lens.
The 12-40 zoom is big and needs to be installed to the camera from the front of the housing after the camera has been installed into the housing. The dome in then installed over the lens and secured to the housing. Once in place the vacuum system assures a proper seal on the dome to the housing.
I shot the lens mostly at wide F/stops to see how well the lens works in the wider aperture range. I also attached an over/under shot so you can get an idea of how the dome handles that task.
Over/under 12mm, ISO100, F/6.3, 1/320th.
Octo, 12mm, ISO100, F/7.1, 1/320th.
Octo vertical, 40mm, ISO100, F/5.0, 1/320th.
Octo underside, 40mm, ISI100, F/5.0, 1/320th.
Star, 40mm, ISO100, F/2.8, 1/320th.
100% star detail.
All are full frame, no crop, using two Inon Z-240 strobes attached to the balls on the grips (no strobe arms used.