I think the WACP-C is a very good fit for all camera formats where wet lenses are not an option and there are many out there.
However for the e-mount moving from the WWL-1 to the WACP-C only means access to the Sony 28-70 which is the original kit lens of the A7 series. This lens is marginally better than the 28-60mm some people even say it is worse but it is not and gives some more range on the tele end.
I have been shooting in controlled environment the WWL Wet and Dry aka WWL-1 and WACP-C for both photos and videos
My view is that using the Sony 28-60mm lens there is no real difference between the two water contact optics in terms of image quality at distances of 0.5m and more for group of divers and schools of fish (though for my tests I only had group of divers). At close range both lenses need to be stopped down a lot to give good performance and there is not much between the two using the sony 28-60mm to be worth it.
I believe the substantially identical image quality with the 28-600 is driven primarily by the dimensions of the lens which I want report below. I have had access to the WACP-C prototype that does not have a float collar but is very much the same lens as the production version. So I could run a fair side by side comparison. Wet means wwl-1 dry means WACP-C (which is the WWL Dry mount)
Length
Wet 97
Dry 110
Dome Size
Wet 4.33"
Dry 5"
Width
Wet 126
Dry 147
For all intents and purposes the WWL-DRY aka WACP is a lens that is 15% larger than the WWL-1. This is not large enough to make a real impact on image quality as far as I can see. There is also no benefit in itself for the dry mount. In fact it would appear that the WWL-1 performs better in back lit shots.
I believe other lenses could make the WACP-C a stronger proposition for e-mount in terms of image quality. I am testing the Tamron 20-40mm 2.8 and the results are superior by all means to the Sony 28-60 especially at close range. This lens stops at 40mm if you need more zoom the best option remains the Sony 28-70. I have flagged this lens to Nauticam and they are investigating it. Will post test photos when I can.
