Still on the fence about the best option for me to buy when it comes to a versatile underwater zoom.

But I have a question for those of you who have shot both:

If you were to try and quantify the sharpness increase of using a WACP-C vs a 16-35mm and glass dome, what do you think we'd be looking at ?

Marginally sharper, or a substantial increase?

I do not have Sony 16-35mm, but I use the similar Tamron 17-28mm/Zen DP170 and also have WACP-C/28-60mm with A7R5...

In the center and midframe the Tamron is clearly sharper and has more contrast compared to the WACP-C combo.

The edges look different with rectilinear (Tamron) compared to moderate fisheye (WACP-C), it is not just corner sharpness that is different. I, personally, prefer the fisheye look (=object in the center enlarged and corner compressed (instead of stretched out as with rectilinear WA)). I guess that at comparable aperture WACP-C is sharper in the corners (this is what Nauticam says, but note that aperture values of the lenses alone (28-60mm vs. e.g. 16-35mm rectilinear are not directly comparable, as the wetlens changes the angle of view and, hence, focal length), but never did a a rigorous comparison myself (I find that corner sharpness not seldom is less important).

For me, personally, the Sony 20-70mm f/4 with Zen DP170 is enough when rectilinear WA is concerned with FF. At 20mm the "rectilinear distortion" is still decent and the image is tack-sharp with brilliant microcontrast i center and midframe (clearly sharper and more contrast than WACP-C).

When wider angles than 20mm are required (majority of cases), I prefer WACP-C/28-60mm (recently, since approx. 1 year), I prefer the Canon 8-15mm/2x Sony TC, which gives similar IQ, but has a more versatile zoomrange compared to WACP-C (for widest 180° diagonal angle the pure 8-15mm gives best IQ, but unfortunately one cannot zoom in))...

Wolfgang

Edited September 21, 2025Sep 21 by Architeuthis

Interesting, so you reckon that the sharpness advantage only really comes in the corners ? And not the centre ?

That's so weird, I would have thought that a WACP-C would out perform a zoom behind a dome substantially, otherwise what is the point of spending all that money on the optic haha...

6 hours ago, Hunting for Paradise said:

Interesting, so you reckon that the sharpness advantage only really comes in the corners ? And not the centre ?

That's so weird, I would have thought that a WACP-C would out perform a zoom behind a dome substantially, otherwise what is the point of spending all that money on the optic haha...

Sharpness and microcontrast in the center are not affected by a domeport and when Tamron 17-28mm or Sony 20-70mm are regarded, are better compared to the WACP-C/18-60mm combo (this is noticed in very clear waters only, otherwise the water is the rate limiting factor). This is not just my subjective opinion (I did not measure with testcharts, just by looking at the photos), but several others here have similar impression...

Furthermore, many (but not all) prefer the moderate fisheye look over the rectilinear WA look. The wider the angle, the more elongated the parts of the motif close to the corners become, when using rectilinear lenses behind domeport (I find this effect far from optimal). An exception may be motifs (e.g. wrecks) where there are straight lines that potentially can get distorted, but even here many (including me) still prefer fisheye and take care how to place these straight lines into the final photo so that the effect does not become distracting...

The WACP-C/28-60mm provides a useful zoomrange in a handsome package compared to many rectilinear lenses behind domeports (many here, BTW, say that WACP-C/28-60mm performs essentially the same as WWL-1/28-60mm (what is smaller, lighter and cheaper, but a wetlens)). It is difficult to predict how WA lenses perform behind a domeport. For most WA lenses, however, a 230mm domeport is considered to be required to give acceptable corner sharpness. The Tamron 17-28mm is an exception, since it performs already very well behind a 170mm (or 180mm) domeport...

Edited September 22, 2025Sep 22 by Architeuthis

Hello. I also photograph the WACP-C with a Sony 28-60. You can see the flares in these pictures. These are not special pictures and straight out of the camera, but you can see the flares more or less clearly in all of them. It depends heavily on the angle of the camera and only occurs when the sun is directly in the picture near the surface (very bright). However, it can be controlled with a quick glance. However, I didn't really pay attention to it when taking the pictures and just snapped away. I also got many pictures with the sun but without flares during these dives.

I'm happy with the setup, but like all other solutions, it has its pros and cons :-)

On 10/2/2025 at 9:53 PM, samuel.heim said:

Hello. I also photograph the WACP-C with a Sony 28-60. You can see the flares in these pictures. These are not special pictures and straight out of the camera, but you can see the flares more or less clearly in all of them. It depends heavily on the angle of the camera and only occurs when the sun is directly in the picture near the surface (very bright). However, it can be controlled with a quick glance. However, I didn't really pay attention to it when taking the pictures and just snapped away. I also got many pictures with the sun but without flares during these dives.

I'm happy with the setup, but like all other solutions, it has its pros and cons :-)

Hey man, thanks for sharing these images. Those flares look pretty nasty. I am seriously considering the WACP-C as an all-round lens, but after seeing this, I might go with the traditional dome port and 16–35mm setup instead.

Does this happen every time you shoot toward the sun? I actually enjoy shooting into the sun when using strobes because it creates great sunballs, so I'm wondering how much of an issue this is in practice.

On 10/2/2025 at 9:53 PM, samuel.heim said:

Hello. I also photograph the WACP-C with a Sony 28-60. You can see the flares in these pictures. These are not special pictures and straight out of the camera, but you can see the flares more or less clearly in all of them. It depends heavily on the angle of the camera and only occurs when the sun is directly in the picture near the surface (very bright). However, it can be controlled with a quick glance. However, I didn't really pay attention to it when taking the pictures and just snapped away. I also got many pictures with the sun but without flares during these dives.

I'm happy with the setup, but like all other solutions, it has its pros and cons :-)

Hey man, thanks for sharing these images. Those flares are pretty brutal. I was seriously considering the WACP-C as an all-round lens, but after seeing this, I might go with the traditional dome port and 16–35mm setup instead.

Does this happen every time you shoot toward the sun? I actually enjoy shooting into the sun when using strobes because it creates great sunballs, so I'm wondering how much of an issue this is in practice?

On 10/2/2025 at 9:53 PM, samuel.heim said:

Hello. I also photograph the WACP-C with a Sony 28-60. You can see the flares in these pictures. These are not special pictures and straight out of the camera, but you can see the flares more or less clearly in all of them. It depends heavily on the angle of the camera and only occurs when the sun is directly in the picture near the surface (very bright). However, it can be controlled with a quick glance. However, I didn't really pay attention to it when taking the pictures and just snapped away. I also got many pictures with the sun but without flares during these dives.

I'm happy with the setup, but like all other solutions, it has its pros and cons :-)

Hey man, thanks for sharing these images. Those flares look pretty nasty. I am seriously considering the WACP-C as an all-round lens, but after seeing this, I might go with the traditional dome port and 16–35mm setup instead.

Does this happen every time you shoot toward the sun? I actually enjoy shooting into the sun when using strobes because it creates great sunballs, so I'm wondering how much of an issue this is in practice.

On 10/2/2025 at 9:53 PM, samuel.heim said:

Hello. I also photograph the WACP-C with a Sony 28-60. You can see the flares in these pictures. These are not special pictures and straight out of the camera, but you can see the flares more or less clearly in all of them. It depends heavily on the angle of the camera and only occurs when the sun is directly in the picture near the surface (very bright). However, it can be controlled with a quick glance. However, I didn't really pay attention to it when taking the pictures and just snapped away. I also got many pictures with the sun but without flares during these dives.

I'm happy with the setup, but like all other solutions, it has its pros and cons :-)

Hey man, thanks for sharing these images. Those flares are pretty brutal. I was seriously considering the WACP-C as an all-round lens, but after seeing this, I might go with the traditional dome port and 16–35mm setup instead.

Does this happen every time you shoot toward the sun? I actually enjoy shooting into the sun when using strobes because it creates great sunballs, so I'm wondering how much of an issue this is in practice?

On 9/21/2025 at 11:56 AM, Hunting for Paradise said:

Still on the fence about the best option for me to buy when it comes to a versatile underwater zoom.

But I have a question for those of you who have shot both:

If you were to try and quantify the sharpness increase of using a WACP-C vs a 16-35mm and glass dome, what do you think we'd be looking at ?

Marginally sharper, or a substantial increase?

The FoV is quite different on those two options, a WACP (or WWL) and a 16-35 behind a dome. The former will give you 130 degrees on the wide end, a 16 will give you around 105 on a FF sensor.

130 degrees

Edited yesterday at 06:36 AM1 day by Christian K

2 hours ago, Christian K said:

The FoV is quite different on those two options, a WACP (or WWL) and a 16-35 behind a dome. The former will give you 130 degrees on the wide end, a 16 will give you around 105 on a FF sensor.

130 degrees

Yeah, the wider field of view is definitely nice, but from what I've seen, the image quality itself doesn't seem dramatically better, maybe better around the corners. For something that costs €3k+, I'd expect a much more noticeable improvement compared to the regular domes. The comparison images I've seen, especially in situations shooting against the sun, don't really convince me that the image quality is significantly better, but maybe I am wrong...

9 hours ago, AlexUW26 said:

Yeah, the wider field of view is definitely nice, but from what I've seen, the image quality itself doesn't seem dramatically better, maybe better around the corners. For something that costs €3k+, I'd expect a much more noticeable improvement compared to the regular domes. The comparison images I've seen, especially in situations shooting against the sun, don't really convince me that the image quality is significantly better, but maybe I am wrong...

We’re shooting in water. So ask yourself how much closer you can be to a subject / something you want to shoot with 25 extra degrees of FoV and what that does to IQ.

Edited 23 hours ago23 hr by Christian K

11 hours ago, Christian K said:

We’re shooting in water. So ask yourself how much closer you can be to a subject / something you want to shoot with 25 extra degrees of FoV and what that does to IQ.

Yeah that's a great point :)

On 6/15/2026 at 2:33 PM, Christian K said:

The FoV is quite different on those two options, a WACP (or WWL) and a 16-35 behind a dome. The former will give you 130 degrees on the wide end, a 16 will give you around 105 on a FF sensor.

130 degrees

Actually quoting diagonal fields of view is a bit misleading when comparing rectilinear lenses to barrel distorted wet optics as with barrel distortion the corners are stretched the most. It would be quite rare to place a subject like a whale, a shark or even a wreck along the diagonal axis, rather they are placed along the horizontal axis typically, so in my view comparing the horizontal fields gives a truer picture of the difference in subject size they can accommodate.

The horizontal field of a 16mm rectilinear is 96 degrees, while a WWL at the widest is about 106 degrees in the horizontal axis, which is about a 13.5mm rectilinear lens horizontal field. so the horizontal field of view is only 10 degrees wider not 25 degrees wider. All that said I wouldn't take a bit dome down to shoot whales if i Could get similar fields from the smaller wet optics. A fisheye has a 144 degree horizontal field in comparison so is significantly wider.

20 minutes ago, Chris Ross said:

Actually quoting diagonal fields of view is a bit misleading when comparing rectilinear lenses to barrel distorted wet optics as with barrel distortion the corners are stretched the most. It would be quite rare to place a subject like a whale, a shark or even a wreck along the diagonal axis, rather they are placed along the horizontal axis typically, so in my view comparing the horizontal fields gives a truer picture of the difference in subject size they can accommodate.

The horizontal field of a 16mm rectilinear is 96 degrees, while a WWL at the widest is about 106 degrees in the horizontal axis, which is about a 13.5mm rectilinear lens horizontal field. so the horizontal field of view is only 10 degrees wider not 25 degrees wider. All that said I wouldn't take a bit dome down to shoot whales if i Could get similar fields from the smaller wet optics. A fisheye has a 144 degree horizontal field in comparison so is significantly wider.

Agree somewhat. Often numbers don't tell the whole story. Anyways, 11 degrees (107 on wwl/wacp) difference horizontally makes for quite some difference in many UW shooting situations inme and inmo. The "square" you have available to frame your image from a desired distance (less than 1.5 metres, preferably less) is quite a bit larger with a wacp/wwl, compared to a 16 mm rectilinear lens. Shooting style and preferences then vary of course and different shooters want different solutions. The WWL and WACP (full disclosure –– have not used WACP, so merely a qualified guess) have some mild barrel distortion, but not as much as a full-blown FE. Kind of like the Tokina on DX @ 16-17, perhaps a little less.

Fisheye 180 degrees, trying to make use of the diagonal FoV.

Edited 5 hours ago5 hr by Christian K

1 hour ago, Chris Ross said:

Actually quoting diagonal fields of view is a bit misleading when comparing rectilinear lenses to barrel distorted wet optics as with barrel distortion the corners are stretched the most. It would be quite rare to place a subject like a whale, a shark or even a wreck along the diagonal axis, rather they are placed along the horizontal axis typically, so in my view comparing the horizontal fields gives a truer picture of the difference in subject size they can accommodate.

The horizontal field of a 16mm rectilinear is 96 degrees, while a WWL at the widest is about 106 degrees in the horizontal axis, which is about a 13.5mm rectilinear lens horizontal field. so the horizontal field of view is only 10 degrees wider not 25 degrees wider. All that said I wouldn't take a bit dome down to shoot whales if i Could get similar fields from the smaller wet optics. A fisheye has a 144 degree horizontal field in comparison so is significantly wider.

So you'd take a fisheye for whales? I always thought it was better not to go too wide with large pelagics. I photographed orcas and whales in Norway with my 16–35mm, and that worked well. Sure, there were moments when it wasn't quite wide enough, but at the same time the animals were often farther away than expected. I don't really know how close they typically get in French Polynesia, though. I don't have a huge amount of experience shooting whales...

24 minutes ago, Christian K said:

Agree somewhat. Often numbers don't tell the whole story. Anyways, 11 degrees (107 on wwl/wacp) difference horizontally makes for quite some difference in many UW shooting situations inme and inmo. The "square" you have available to frame your image from a desired distance (less than 1.5 metres, preferably less) is quite a bit larger with a wacp/wwl, compared to a 16 mm rectilinear lens. Shooting style and preferences then vary of course and different shooters want different solutions. The WWL and WACP (full disclosure –– have not used WACP, so merely a qualified guess) have some mild barrel distortion, but not as much as a full-blown FE. Kind of like the Tokina on DX @ 16-17, perhaps a little less.

Fisheye 180 degrees, trying to make use of the diagonal FoV.

Great image!

39 minutes ago, AlexUW26 said:

So you'd take a fisheye for whales? I always thought it was better not to go too wide with large pelagics. I photographed orcas and whales in Norway with my 16–35mm, and that worked well. Sure, there were moments when it wasn't quite wide enough, but at the same time the animals were often farther away than expected. I don't really know how close they typically get in French Polynesia, though. I don't have a huge amount of experience shooting whales...

Yes!

I took these images at Magdalena Bay last year snorkeling. The first humpback shot was taken from about 2-3 feet distance. I don't think this would have been possible with a rectilinear lens.

If I did this again I would probably add a 1.4tc to the lens. You can still get the same width at 11mm but you have a bit more reach when things are further away.

Nikon Z8 w/8-15mm Fisheye lens, f8@1/250s iso640, Nauticam 140mm dome, Natural Light

51 minutes ago, AlexUW26 said:

So you'd take a fisheye for whales? I always thought it was better not to go too wide with large pelagics. I photographed orcas and whales in Norway with my 16–35mm, and that worked well. Sure, there were moments when it wasn't quite wide enough, but at the same time the animals were often farther away than expected. I don't really know how close they typically get in French Polynesia, though. I don't have a huge amount of experience shooting whales...

In my view (finder), def a fisheye for whales, whale sharks, manta rays and friendly sharks (baited), reef-scapes, big aggregations of fish and perhaps wrecks. A WACP / WWL for manta rays and baited + chance encounters with sharks, reef-scapes and fish aggregations of fish / schools. Others might do it different.

Rectilinear 16 mm, 105 degrees FoV. A little bit more wouldn't have hurt.

Edited 3 hours ago3 hr by Christian K