5 hours ago, Chris Ross said:

There are a number of constraints when using lenses behind water contact optics, there is an entrance pupil constraint and there are also issues with zoom lenses that change length as they zoom

I looked into using the z24/1.8 with the wwl-c a while ago and this was the issue. Front element cause vignetting.

Edited 2 hours ago2 hr by Christian K

3 minutes ago, Christian K said:

I looked into using the z24/1.8 with the wwl-c a while ago and this was the issue. Front element cause vignetting.

Yes, it's unclear exactly what sets this and it varies between the WWL and WACP models as to which lenses they work with. I would guess that port charts for these optics are fairly complete and to get a better optic use the chart to help, but probably involves going to a WACP. I would think that the main limitation with some of these bigger lenses is the flat port size (port ID or the m67 port diameter causing vignetting), or some of the small primes a short enough port to properly accommodate them.