The range of wet interchangeable wide-angle lenses available on the market has exploded recently. Some years ago there was really only Inon that made lenses that were considered useful for underwater photographers. Today the range of lenses has expanded in price-terms also, as companies like Nauticam have started to produce super high-quality (and expensive) underwater lenses. For this test, I have chosen 4 affordable (under £470.00) lenses that are all reasonably compact. The classic Inon UWL-H100 is also included and going to be measured up against 3 relatively fresh newcomers.\nThe lenses in this test are:\n- Weefine WFL-12 M67- Inon UWL-H100 M67 (type2)- Fantasea\/AOI UWL-400 F\/Q- Weefine WFL-02\nPlease note that this test is not a scientific test and I will not be able to measure exact angles of views of the lenses in water. The lenses here are only tested against each other in the view angle and corner sharpness. (The test images were taken in water so that the camera is stationed 15cm away from the measuring tape). I took the test images with two different cameras. Canon G9XII, which has a 28mm lens and Sony RX100 VA which has a 24mm lens. I’ve only included the 24mm images below as if the test lenses work with the 24mm view angle, they also will be fine with 28mm. All test images were taken at f5.6 to reduce the corner blur. Closing your aperture is something that generally advised when using wet interchangeable lenses.\nReference image without an additional lens. (notice the pincushion effect)\n1. Weefine WFL-12 M67 lens\nThe newest of the lenses in this test is the Weefine WFL-12 M67. It is also the cheapest one of the bunch by far, costing only £209 in the UK. The WFL-12 lens is more of a corrective dome element than an actual wide-angle lens, unlike the rest of the units in this review. These kinds of corrective domes, often called “air lenses” have been available from different manufacturers for a while now. They are an easy way to get into wide-angle lens photography as they usually are small and cheap. They are also easy to use as they don’t require the user to get that close to the target. The Weefine WFL-12 M67 lens has a magnification of 0.72x and is designed to work with 24mm lenses giving you 90-degree angle in water. The name “air lens” means that these lenses, at least in theory, remove the magnification and aberration issues of water and keep the angle of view of the camera lens as it would be out of water. They also neutralise the pincushion distortion that happens with all flat ports when submerged. The WFL-12 lens is all aluminium construction including the shade and comes with a polycarbonate dome port and neoprene lens cover. The WFL-12 lens has a 67mm port thread and will work with most cameras with short zooms. There is also a 52mm version of this lens available, the WFL-11 M52, that is designed for the Olympus PT-059 housing.\nAs you can see, the lens works well and is surprisingly sharp towards the edges of the frame. A bonus is that this lens can be fully zoomed through. The three other lenses in this review will not work once you move the camera lens further into a tele-position. It’s not bad for £209\n2. Inon UWL-H100 M67 type 2\nThe Inon UWL-H100 M67 has been the workhorse underwater wide-angle lens for years and has generally been the lens that introduces photographers to underwater wide-angle work. This solid aluminium lens comes with glass elements and replaceable M67 thread. The lens is available also as a bayonet version called the 28LD, which was until a few years ago the main connection method. Inon has now all but stopped making the bayonet adapters for housings and today 95% of these lenses sold are the threaded version. But if you happen to have the bayonet version of this lens you don’t have to bin it when updating your camera and housing. Just swap the rear bayonet to the standard thread, which is available as an accessory.\nThe inon UWL-H100 M67 lens gives you a theoretical view angle of 100 degrees in water (on land the view angle is actually around 170 degrees but most of that is lost to the refraction when submerged). If you want to improve the angle underwater you can add the Inon glass dome lens unit that increases the maximum view angle to around 140 degrees. Together the lens and the dome makes a compact fisheye lens with perfect image quality. The combo, however, ends up costing around £750 (£399.00 for the lens and £359.00 for the dome). You will also need to spend money on the lens hood as it does not ship as standard with the UWL-H100 lens.\nAs you can see, the angle increases a little from the WFL-12 lens. But due to the UWL-H100 lacking a dome port the edges tend to get quite unsharp and the colour split is visible.\n3. Fantasea\/AOI UWL-400 F\/Q\nThe Fantasea UWL-400 lens is a super wide-angle lens that comes in two versions. The F model has a fixed M52 port thread whereas with the Q model you can also use the Fantasea’s quick-release bayonet adapters. Optically both the lenses are the same. This lens is manufactured by AOI and in some countries, it is sold with that name. The UWL-400 lens is a surprisingly compact unit with a polycarbonate dome port and a plastic lens hood. Both the F and Q version comes as standard with 52mm thread, which today is only really suitable for the Olympus tough housings like the PT-058 and 059. Included in the box is also a special M76 lens adapter that allows the use of the lens on standard M67 ports with minimal loss of picture quality. The lens is also supplied with a neoprene dome port cover.\nOn paper, the magnification of this lens is 0.5x and maximum view angle 120 degrees. The 120-degree view angle puts the lens into a unique category between a wide-angle lens and an underwater fisheye lens. This lens is the most expensive of the lot costing £435.00 for the F version and £475.00 for the Q versions.\nThe UWL-400 is considerably wider than the two earlier lenses. The dome port eliminates the colour splitting almost completely. Some natural blur is visible in the corners of the frame (partly distance related) but this could be reduced by choosing a smaller aperture. An annoying issue with this lens is the tiny M52-M67 adapter ring. When using the lens on a standard M67 port, it is impossible to grab the ring, in case you would like to swap the unit for a macro lens. This means that after taking the lens off you will need to remove the lens ring separately. In an ideal world, you would like them to stay together.\n4. Weefine WFL-02 M52\nThe final lens for this review is the Weefine WFL-02 fisheye lens that is an updated version of the popular WFL-04 fisheye lens. The WFL-02 lens is aluminium bodied with polycarbonate dome and 52mm thread. It has been specially designed to be used with camera lenses as wide as 24mm. It is the largest of the lenses in this review but also gives by far the widest view, up to 150 degrees. On paper, the lens magnification is 0.47x. Although originally designed for Olympus tough cameras this lens will work on almost all compact cameras with short zooms with the handy M52-M67 lens adaptor, which is available separately. This lens is also compatible with some Olympus micro four-thirds models with certain lenses. The WFL-02 costs £389.00 in the UK (the lens adapter is £12.00) The Weefine WFL-02 comes with a hardened carry case and a neoprene cover with Velcro fastening\nThe WLF-02 is unsurprisingly the widest of the tested lenses. As you can see, I even run out of measuring space. The large dome port keeps the image reasonably sharp to the edges even with f5.6 aperture. No colour splitting is visible. The larger lens adapter, in comparison with the Fantasea, makes it easier to remove the lens as you can grab the adapter itself when screwing the lens off.\nFinal words.\nAll the tested lenses behaved almost as expected in line with the specifications. There are, of course, a few surprises. Especially I am surprised to see how near the £209.00 Weefine WFL-12 lens comes to the £399.00 Inon UWL-H100 lens. The angle difference in practice is negligible and the domed lens unit of the Weefine eliminates the worst colour splitting effects. In my opinion, the almost 200 quid price difference is not worth the few extra degrees… especially as for this price, with the Inon, you do not get a lens hood or a neoprene cover.\nThe compact Fantasea UWL-400 lens’ best feature is its size to view angle ratio. The in-between angle of 120 degrees might be good for photographers who are not yet ready to go full fisheye. For the Q version, the availability of the quick release system is also a plus. It is a pity that this lens is a bit overpriced though. The quick-release parts, that are all separately available are not cheap either.\nThe Weefine WFL-02 lens offers great fisheye quality with a reasonably cheap price tag. It’s no wonder that this lens is increasingly popular with underwater photographers. If you want a high-quality underwater fisheye lens that does not break the bank it’s the obvious choice.\nFinal note: One of the most frequently asked questions I hear is if these kinds of lenses can be used with the Canon G7X MKII and MKIII cameras. These popular cameras models have a large lens that moves a lot inside the housing. This means that the port of the housing needs to be large also. Unfortunately, this leads to the fact that none of the standard wide-angle lenses can be used with a G7X housing that has a fixed port like the Fantasea. The only way to use these lenses is to go for a brand that offers a removable front port that can be swapped to a shorter one. Currently, at least Nauticam and Isotta are offering this option with their G7X housings.