10 hours ago, RomiK said:

I second this very much. Had it, tested it and returned it. Very very very soft. It will translate to UW performance too. One certainly wont be able to use WACP-C/28-70 to get this (WACP-C/28-60 @60)

I am not sure your example makes sense. The 60mm end of the 28-60 has a max magnification of 1:6.25 while the 28-70 II at 70mm has a magnification of 1:5.5. It can also focus well beyond 30 FPS and unlike the 28-60 it also has in lens stabilization. If you are suggesting that the IQ at 70mm is worse than at 60mm or that the 28-60 has some other medical advantage I offer these images to compare.

Like many of you I have look at terrestrial reviewers and flat charts to adnauseam over six decades. Everything in photography and even more so in underwater photography is a tradeoff. My opinions are based on years of U/W tests both my own and others I trust.

The first image is the 28-60mm at 60mm with WACP-C and A7R v, shot at F/11, 1/160th sec at ISO-400.

Second image is the FE 28-70mm II with MX 135D and A7R VI, shot at F/11, 1/250th at ISO-640.

Both images un-cropped and both taken at same distance from the glass +/- a MM or two

12 hours ago, Architeuthis said:

Are there more resilient tests existing that demonstrate the superior IQ of the Marelux 135D over WACP-C?

It may be that UW, behind water contact optics, the IQ of the Sony 28-60mm and 28-70mm lenses is not different. Over the water, both 28-70mm lenses, are clearly inferior and pretty soft. See here, for examle:

https://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=1759&Camera=1538&Sample=0&FLI=0&API=1&LensComp=1525&CameraComp=0&FLIComp=0&APIComp=0

There is no difference, BTW, in the optical design between Sony FE 28-70mm f/3.5-5.6 OSS and the newer "II" version. The difference is mostly in AF mechanism and performance...

First of all I have used WACP-C and 135D, both Nauticam and the Marelux lenses are excellent choices paired with the FE 28-60 or FE 28-70mm lenses. If you are relaying on the attached review site then read the Sony FE 28mm F/2 review. If by your logic we should be using the best under $500.00 lens for WACP-C/135D then the 28mm would be it according to your source. But because everything in underwater is a trade off most chose a zoom over a fixed lens.

The first reason I think the Aquista 135D is better than WACP-C has to do with physics. The larger diameter glass produces better image quality in most cases. Making WACP-C better than WWL-1/B, WACP-2 better than WACP-1 and Aquista 135D better than WACP-C because glass diameter between WACP-1 and WACP-C. Many other factors are involved but most get back to the U/W photo trade offs like cost, weight, size, travel, brand loyalty, system compatibility and much more.

I have tested all of the wet lenses listed above and many more from AOI, Inon, Kraken, OM/Olympus, Weefine and more. I have come to the realization over the years that in-water testing is the best metric for evaluation. Example, the original WWL-1 was first sold without a float collar, none existed other than in one of the prototype lens mounts which had a small aluminum . After in water testing by Peter Rowlands suggested to Nauticam that they come up a flotation device and the float collar was offered as an accessory. This is also the way that we discovered bubbles being trapped between the flat port and WWL.

I am attaching several photos the first is with a Sony FE 16mm F/1.8 in a 180mm dome port. I am showing this photo because of another urban legend that rectilinear lenses are softer in the corners than fisheye lenses like the 8-16 and assorted 130 degree wet lenses.

The first image was shot at F/8 and is much sharper out into the corners than any 180/130 fish I have used.

The second image is at 28-60mm at 28mm with the WACP-C and A7R V at F/11, 1/200th, ISO-400. Sharp center light but begins to fall-off in sharpness as you move out from the light.

The third image is at 28-70mm at 28mm with Aquista 135D and A7R VI at F/11, ISO-640, 1/250th. The center light is just as sharp as with 28-60mm and with the 135D fall-off in sharpness as you move out extended beyond where it does with WACP-C.

Closeup sharpness at #1 60 and #2 70mm appears equal as well.

Be aware all images are full frame and shot in A priority with AV light.

13 hours ago, Phil Rudin said:

I am not sure your example makes sense.

It makes sense in a sense that a sharp lens will produce sharp results if the attachment to it is sharp while you can't make soft lens to produce sharp result no matter what. So if 28-60@60 is razor sharp the 28-70@70 magnification means absolutely nothing if it is soft. Because that sea horse image example is - obviously - very significant crop from 50Mpx Sony A1 sensor. If it makes sense now.

Now it seems like waterpixels engine strips metadata from images posted to the discussions so you can't see that the seahorse image is at F8

While 28-70 did show some improvements at higher apertures like F13+ it still did not reach the sharpness of 28-60 by any means. For 50mp instagram image it won't matter but if you need to crop it will.

Perhaps 100% crops from your samples may bring more clarity? You are a pro so you know it also matters where the camera was focused. The bulging light element might not the best for testing. I tested my 28-60 and 28-70 samples on a flat photography chart 🤷

12 hours ago, RomiK said:

I tested my 28-60 and 28-70 samples on a flat photography chart 🤷

Flat chart may also not be the best for testing lenses underwater if the lenses exhibit field curvature, as many do.

I prefer real world dive conditions, using complex subjects like seagrass, or subjects surrounded by macro algae. I look for something sharp in the corners that should be sharp, comparing that with the sharp centre. They may not be in exactly the same plane, although they generally are at macro distances. With wider fov, corner sharpness is often better behind the subject plane.

On 10/27/2026 at 6:00 AM, RomiK said:

It makes sense in a sense that a sharp lens will produce sharp results if the attachment to it is sharp while you can't make soft lens to produce sharp result no matter what. So if 28-60@60 is razor sharp the 28-70@70 magnification means absolutely nothing if it is soft. Because that sea horse image example is - obviously - very significant crop from 50Mpx Sony A1 sensor. If it makes sense now.

Now it seems like waterpixels engine strips metadata from images posted to the discussions so you can't see that the seahorse image is at F8

While 28-70 did show some improvements at higher apertures like F13+ it still did not reach the sharpness of 28-60 by any means. For 50mp instagram image it won't matter but if you need to crop it will.

Perhaps 100% crops from your samples may bring more clarity? You are a pro so you know it also matters where the camera was focused. The bulging light element might not the best for testing. I tested my 28-60 and 28-70 samples on a flat photography chart 🤷

I don't wish to beat this to death Romik but I am sure my A7R VI with 66+ MP would expose flaws slightly more than the A1 50MP.

I would expect F/8 to render slightly better images than the F/11 I was shouting due to refraction.

I have attached a full frame image and a more than 200% crop at 70mm and F/11. The crop appears sharp to me.