JayceeB

"I think, the marelux 180 glass dome or their 210 acrylic will not add much volume or load and dramatically improve lens performance." @Adventurer I'm considering the 180mm. I haven't had great luck with larger acrylic domes, as the ones I've used require weight to keep them from nosing up. "I assume the freshly introduced Marelux Aquista 135D - which is Marelux‘s take on Nauticam‘s WACP lineup - will give you the highest image quality with that lens," @Adventurer . For me, the improvement in image quality would need to be significant to justify the cost and heavier weight (for shore diving) of the Aquista 135D. A little out of my budget for testing purposes. I'm interested to see the results though, once someone is able to test and report back.

I haven't been able to find a way to turn off lens correction in camera. You can turn it off in Lightroom after importing, but Lightroom defaults to applying it. I prefer lens correction on for the 20-50mm and 14-35mm, but lens correction off for the 8-15mm fisheye.

Tiger @27mm. Dolphins @20mm.

1/250 sec at f/10, ISO 320 @45mm

I did not add a diopter. I have been shooting this setup with 140mm dome and 30mm extension, which is the recommended port and extension for the EF 8-15mm fisheye. As I mentioned earlier in this thread, I was able to re-use the zoom gear from my RF 14-35. I've taken it on 5 dives and one offshore shoot for big animals. To be honest, I have been very surprised at how well it has worked in the tiny dome. I know the edges will not be acceptable for some, but for me, I am satisfied. I mainly shore dive, so lugging a bigger dome down rocky entries can be a handful, as well as exiting in rough conditions. There are definite dark corners without lens correction at 20mm, so lens correction is mandatory. This zoom range is very useful for most of my diving, and I think it may end up being a popular choice underwater use for some people. I have been able to shoot Harlequin shrimp (cropped) and dolphins on the same dive. I'll upload a few more shots at various focal lengths.

Yes. If I turn 'Enable Profile Corrections' to 'On', I get the banding. The banding is more exaggerated when zooming in. At 20mm, it is negligible.

Last photo cropped lower left to show the Lens Profile banding on the border introduced by Lightroom.

Same settings, but at 50mm. Color corrected a bit.

I was able to try this lens out yesterday underwater in a 140mm dome. 1/160 sec at f/8.0, ISO 100 @ 20mm. I bumped up the exposure +.55 in Lightroom, but otherwise no other changes. One negative, is the Lightroom Profile Correction for the new lens leaves a thin border banding. I assume future versions will fix this.

I use a couple of different blowers as part of my routine. Milwaukee compact leaf blower immediately after removing housing from the rinse tank. Blow off excess water on housing and dome/port. M18™ Compact Blower (Bare Tool) | Milwaukee ToolMILWAUKEE® M18™ Compact Blower delivers the fastest jobsite cleanup. Offers a best in class power to size ratio and comes with a universal inflator/deflatorWolfbox MF200 to blow off o-ring moisture on lights, strobes, housing, ports. https://wolfbox.com/products/compressed-air-duster-mf200?

Good news. Although the diameter lens spec for the 20-50mm is 80mm and 14-35mm is 84mm, the marelux zoom gear for the 14-35mm fits the 20-50mm (snugly). I took 3 of the rubber shims off the inside of the ring that contacts the lens barrel. Next will be figuring out the extensions required.

RF20-50mm lens arrived. I do not yet have a zoom gear. Tried mapping the PZ zoom in/out to custom buttons, but the R5 does not allow this option, even with the latest firmware. I see Nauticam has a zoom ring for the 20-50. Marelux does not list it, and I haven't heard back from them on whether they plan to. Does anyone know if the Nauticam zoom ring would work inside my Marelux housing?

Perhaps this setting prevented the optical sensor from being active for me. Menu->Setup Menu (yellow wrench)->Screen/viewfinder display (3)->Screen

I set the illumination button to 'display off'. It works with the camera out of housing, but in housing it does not work. I tested it in a Marelux housing. FYI, I have never mapped to this button or used this button via my housing before. Next, I tried covering up the entire back of the camera to see if it was linked to the eye sensor in the Viewfinder. Using the camera illumination button worked fine. I then started fiddling with the housing illumination button. Activating the housing button pushed a lever down that didn't even look close to where the button was on the camera. I wiggled the lever, and it actually rotated easily and was not even secured. I pulled the lever to the top, and it clicked into place. Tested again with the camera in housing, and it worked. The camera lock button lever behaved the same way. Looks like both those levers were never positioned and locked in place. I never noticed because I had never used those housing buttons before. Perhaps the Nauticam housing has the same lever design? Photos showing the lever before and after I rotated the levers up in place.

Hi Wahrmut, I have the R5. Here is how I set it up for Viewfinder/Display. Menu->Setup Menu (yellow wrench)->Screen/viewfinder display (3)->Screen Menu->Custom Functions->Customize buttons(3)->Assign the * (AE Lock button) to 'Switch between VF/screen'. I customized the * (AE Lock button) to toggle between screen and viewfinder, but you could choose another button instead.