The Sony A7R2 was released in 2015 some time later Nauticam released the WWL-1 and I was told this wet lens would work with a Sony full frame using a 28mm prime.

Years later I own a Sony A1 and I have been considering the 28/2 prime as a complement to the Sony 28-60mm mostly to address sharpness issues at the edges.

There is no doubt that the 28-60mm is a great little travel lens and perfect companion of the A7C however performance at the edges is never quite right no matter how much you close down.

Build Comparison

The 28mm prime is smaller than the 28-60mm when this one is extended but has a wider front element.

The side by side comparison shows that the 28mm is 9mm shorter when the zoom is at 28mm. The 28mm has a 49mm filter thread while the 28-60 has a 40.5. The 28mm is two stops faster than the 28-60mm but has a lot of vignetting.

DxoMark says the 28/2 will resolve 47 megapixels when coupled with the A7RIV 62 megapixel sensor.

The lens has quite a bit of distortion but not as much as the 28-60mm and also strong vignetting.

On the A1 the lens looks small and well proportionate to the camera body. Not sure if I will ever use a 28mm prime but I got my copy from Wex photography using a discount code and it was open box.

Port Required

The lens will vignette with the Nauticam flat port 45 and it requires the purposely designed flat port 32. This was released after the new generation of Sony housing as replacement of the flat port 37 used on earlier models.

Not much to say the port is obviously shorter and does not focus a knob.

Topside Comparison

Before taking the camera in water I wanted to make sure the lens was sharper than the 28-60mm and it is.

My assessment topside is that the lens is best at f/5.6 and the 28-60 never really matches it. At f/11 the resolution drops and the two lenses become comparable however there is no benefit shooting the 28mm at smaller apertures than f/8.

You can open the images in a new tab I spare the crop comparisons the 28-60 edges are blurry at f/5.6.

By f/8 there is an improvement at the edges but the centre drops on the 28mm. Likewise on the 28-60mm where the edges become acceptable.

At f/11 the lenses are almost identical. This is an important consideration as underwater this means shooting from f/11 and smaller aperture will not show substantial differences between the two lenses with the WWL-1.

Pool Tests

I set up my camera and went to Inspire Luton for a shooting session.

First I set up the small test reef and took images at various apertures.

I disabled distortion correction so there is a little black bar on the bottom when you are at extreme close range.

The image at f/5.6 shows that on the focus line (the pink coral is the target) everything is good quality as you move to the edges but you can see the depth of field running out as you get closer. Do not confuse this with the lens edge performance as many testers do.

The focus point is on the line Achieve Neutral Buoyancy. You can see that the WWL-1 deteriorates the image quality especially on the meridional lines compared to topside. However this is overall useable in my opinion compared to the 28-60mm.

Closing to f/8 achieves overall the best centre performance.

Edges are more than adequate I would say f/8 is the sweet spot of this lens for shots that are not too close.

At f/11 the WWL-1 in its best performance at the edges but the lens has lost a bit of punch.

Here is a shot at f/16 just to demonstrate the issue of depth of field is unrelated to the lens aberrations.

Personally I would not use this lens for close up work but if you have to f/16 is the way to go.

For reference this is the 28-60mm at f/11 which is totally usable, the shots are not as close so less demand on the lens.

Shooting a target further away demonstrates the ability of the 28mm at wider apertures.

Edges are fine at f/5.6 but this is a flat target.

In conclusion my recommendation for the 28mm is to shoot the lens at f/8 and go to f/5.6 when there is nothing in the edges as necessary to improve centre sharpness. This is an improvement of 1 stop over the 28-60mm. It is not possible to use the lens at f/4 with the WWL-1 the performance is just not there.

Divers Example

The lens has a good contrast and pop.

Shots at f/5.6 are softer at the extreme edges and depth of field also plays a role.

Midwater shots do not display significant issues as expected.

Open Water Shots

I used this lens in Sorrento during my last trip shooting it always at f/8 which was a mistake for close up shots where I should have closed down the aperture.

The shots that follow would have been better suited to a fisheye.

At close range I did not close down to f/16 so the lack of depth of field is evident. Do not confuse this with edge performance.

You can see that as the focus is on the grouper the reef coming outwards is blurred due to lack of depth of field.

This is very apparent on this shot.

I have the impression that those water contact optics work better when focussed closer in the frame not on the target as if the depth of field is mostly behind the focus point.

Wrap Up

The Sony 28/2 costs £339 currently and the flat port another £369 for a total of £708 for the set up.

I have not tested the lens with the WACP-C but I think performance will be worse as the mount has a lot of gap until the back of the lens is reached and this creates other side effect.

I believe that the 28mm prime is not something that you require for a 24 and even 32 megapixel camera. Users of the A1 or A7R series that want the absolute best quality and the ability to shoot one stop more open will look into this lens but the majority of shooters will stay with the 28-60mm as their only lens. For video users I think the 28/2 lens is a non starter and I am not planning to use it at all as in 16:9 the extreme edges are cropped and even the 28-60mm is fine.

I am conscious that a post like this is destined to create some stir, however it reflects over one month of testing of the two Nauticam water contact optics with my A1 and summarizes my conclusion for my own use.

Of course if you are reading this you may agree with what you will read and this will be your conclusion too. Or otherwise you would have bought the WACP-C thinking it was an upgrade for your Sony Alpha and well if it turns out it is not you will think it is anyway.

I was fortunate to be able to borrow the WWL-1 DRY from Alex Mustard. This lens is the prototype of the current Nauticam WACP-C. The lens has remained pretty much the same but it now has an integrated fixed float collar and built in extension. Other than a thickening of the rear lens mount ring it looks identical and therefore I assume optical performance is the same.

Someone will say well but it is not the same, but as we know the construction of the WWL-1, WACP-C and WACP-1 is identical and each model is 1.15 bigger than the previous with the optical design made of 6 lenses in 5 groups for all of them.

I have not had the chance to test the WACP-1, Alex said he would lend me that too however I am not interested in such large lens.

I have also had the opportunity to test the WACP-C with a variety of lenses including some not on the port chart like the Tamron 20-40 F2.8 and 17-28 F2.8 both did very well but nothing amazingly better than that little Sony 28-60 or the Sony 28mm prime and therefore I concluded that path is not worth pursuing.

Sony SEL2860 Lens Options

For the purpose of this article I will focus on the comparison with the Sony SEL2860 F4-5.6 28-60mm which is no doubt not an amazing lens but it happens to be pretty sharp from 35mm onwards. It is rather weak at 28mm at the edges so one of the things I wanted to check was if the larger WACP-C was giving an improvement over the smaller WWL-1.

The Sony SEL28060 is a small lens that needs to be extended for use. When mounted on the A1 is pretty compact, no surprise as this is the kit lens for the A7C.

The lens is longest at 60mm but only 1mm shorter at 28mm which makes it ideal for use behind a wet lens.

To use it on the Sony E-Mount Full frame of new generation with the N100 port system you need the flat port 45 that comes with a rather unuseful knob that I have removed from mine.

The set up with the A1 is very compact and portable the whole housing, wet lens camera, strobes and arms together with camera and lens fit a carry on luggage on every airline of the world.

To use the WWL-DRY aka WACP-C I needed to use my 35.5 N120 to N100 adapter and a 25mm adapter ring. The production version only needs a 30mm N100 extension ring but will be as long as you see here.

There is a considerable difference in weight between the two set ups and the production WACP-C is heavier.

I own the original WWL-1 version with non integrated float collar which is lighter than the current WWL-1B.

In the post title image you see both lenses without floatation.

Pool Tests

In order to perform a comparison I decided to use a semi scientific method consisting of a fixed scene and shots at very close range. The closest the subject is to the lens more stress is induced on the optics that are designed to focus far away. This means that if a lens is better than another at close range when you point them far way the gap will still be there but will reduce.

WACP-C

The first set of tests was performed with the WWL-1 DRY.

I started at f/5.6 not f/4 that looked visually a waste of time. First I tried with the target on a line to see the potential effect of field of curvature and other issues.

At f/5.6 the sides are already blurry. The edges are even more fuzzy.

The images are 6 megapixels feel free to open them in another tab and look for yourself.

Moving to f/8 improves the situation but not as much as you would think.

The edge remain soft at f/8.

From f/11 we have good performance across the frame using the SEL2860.

Note that the focus point is on the edge and this means the issue if solely due to the water contact optic is not a problem of depth of field or field of curvature.

I proceeded to shoot at f/11 and f/8 avoiding f/5.6.

Shooting at f/8 is possible if there is nothing at the edges and the depth of field is sufficient.

WWL-1

The test with the WWL-1 brought practically identical results.

Sides are soft at f5/6 and the slate shows obvious issues of depth of field.

Edges are very similar to the WWL-1 DRY perhaps a bit better.

At f/8 the situation improves as it had happened with the WACP-C.

From F/11 image quality is consistent across the frame.

There is an obvious issue of depth of field so if you are shooting at close range with the 28-60mm you really need to look at f/16 but this was not the point of the tests.

Wrap Up

As you can see by yourself there is really nothing between the two optics and clearly the difference between the wet and dry version is simply in the ergonomics and of course the price. For me there is no reason to consider the WACP-C unless you have serious issues with a wet mount.

After all those tests I decided not to take the WACP-C to Italy and used the WWL-1 for both photos and video with good results.

This shot is taken at 40 meters with the 28-60mm at f/11.

I pretty much used f/11 fixed changing other parameters for the exposure and at time using the zoom.

This is not the red sea it is much darker and as you can see dry suit were in use.

The zoom of the 28-60 has some clear benefits.

Conclusion

The WWL-1 needs the bayonet mount and the flat port 45 to operate with the WWL-1. This comes at cost of $2,119.

The WACP-C needs the N100 extension ring 30 to operate. This comes at $3,426.

If you a Sony full frame E-mount user and have issue dealing with the bubble removal of a wet lens when you jump in the water you can spend $1,306 to avoid yourself the inconvenience. However you will not have any benefit in terms of optical quality and you will be carrying more weight.

For video the wet lens is clearly preferred as you can operate the 28060 with a flat port and wet lenses for close up work.

The WWL-1 remains the true Nauticam master piece and a lens that keeps delivering years after the introduction.