Adding a Fisheye Lens to the Olympus Tough Waterproof Cameras

If the built-in lens on your Olympus Tough TG-5 or TG-4 isn't as wide as you'd like, there's a waterproof fisheye adapter lens that you can snap onto the front that will instantly add a super wide-angle perspective.

The latest Olympus TG-5 has a built-in zoom lens. When you combine with the 4.5mm lens with the small-sized sensor, you get the equivalent field of view of around what a 25mm lens would look like on a full-frame camera (ie. 35mm equivalent). While 25mm is relatively wide, there are times you might want even wider, especially when shooting underwater.

Olympus has their own solution: a waterproof fisheye lens that snaps onto the front of the camera. It’s compatible with all of the Olympus Tough TG series cameras going back to the TG-1. I’ve been using it on the latest model, the TG-5.

The pack is a bundle of two products that work together.

The first is the adapter that lets you connect the lens to the camera. Its model number is CLA-T01 and it’s just a metal adapter ring–there’s no glass. In most instances, it’s not going to do you much good by itself, but there is one advantage to using it alone and leaving it attached to your camera: it lets you clip on a lens cap (one is included with the CLA-T01; its product number is LC-40.5 and it’s a 40.5mm cap). Without the adapter there’s no way to clip on a lens cap.

Close-up of the CLA-T01 adapter.

The CLA-T01 with a lens cap.

The most important part of it is the FCON-T01 Fisheye Converter. That is the lens itself. In addition to the main lens itself there are front and back caps for it.

The FCON-T01 lens.

It’s basically a piece of glass. There are no moving parts. No aperture blades. No focus or aperture rings. So there’s not much that can go wrong. At the same time, there are limits to its flexibility and some things to watch out for.

It comes with front and back caps.

How Wide?

Since the point of this lens is to add a super-wide perspective, I’ll start with some examples of what difference it makes. Below are some side-by-side shots with and without the fisheye attached. With a magnification of 0.76x, it brings the effective focal length out to 19mm.

[before-after viewer_position=”center” orientation=”horizontal” label_position=”one” overlay_color=”#ffffff”  label_color=”#000000″ label_one=”Without Fisheye Lens” label_two=”With Fisheye Lens”]


[before-after viewer_position=”center” orientation=”horizontal” label_position=”one” overlay_color=”#ffffff”  label_color=”#000000″ label_one=”Without Fisheye Lens” label_two=”With Fisheye Lens”]


In addition to the wider perspective, an obvious difference is the distortion with the bowing of the horizon.

Size and Weight

The lens snaps onto the front of the camera. Even though it’s only a little over an inch deep, when attached to such a small camera it makes the whole package quite a lot larger, bringing it closer to a small mirrorless setup. It will still fit in large pockets, but it’s nowhere near as compact as the camera without the lens.

And, relatively speaking at least, it’s quite hefty. It weighs about 4 1/2 ounces (130 grams, approximately). That doesn’t sound like a lot, but relative to the camera itself, it’s half the weight of the camera alone (8.7 ounces / 247 grams).

It’s compatible with the Olympus silicon skin.


The fisheye lens pack works well enough above water, but it probably makes most sense for underwater use. Because of the natural magnification when shooting through water, the extra width that the fisheye offers comes in handy for underwater shooting.

According to Olympus’s own in-house testing, it has a waterproof rating equivalent to IPX8, which means it can be used up to 65 feet deep (20 meters) of water for at least 60 minutes.

That makes sense, because this is basically glass that simply attaches to the camera. Attaching it doesn’t expose any of the camera’s interior–it’s a purely external attachment.

Doesn’t Reduce Aperture

Unlike something like a teleconverter, which reduces the usable aperture range, this lens doesn’t. You can still use f/2 and f/2.8 (you’ll have to use smaller apertures if you zoom in because the camera doesn’t use a constant maximum aperture throughout the zoom range). Of course, adding extra glass to the front does in fact cut down on the amount of light hitting the sensor–that’s just physics–and it has to come from somewhere, but the exposure is compensated in the calculations for shutter speed and ISO so as not to change the usable aperture range.

It doesn’t magically improve the TG-5’s low-light performance, but at least it minimizes the impact.


If you add a large chunk of glass to the front of the lens you can expect to lose some sharpness. And you do with this lens. I was pleasantly surprised with how sharp it remained in much of the center of the frame, but it’s definitely very soft around the edges.

Here’s an example shot at f/8 (click on it it load a full-size version).

This shot illustrates two things: how the fisheye distortion can bend horizons and also that while quite sharp in the middle of the frame, things get very soft around the edges.


The lens does add quite a lot of distortion, as you’d expect. It’s most noticeable when shooting out of the water, especially when there are straight lines like horizons or buildings.

Whether that bothers you is entirely a matter of preference. But here are some examples of the kind of bulging fisheye look you can get.

It also very much depends on where you’re pointing the lens. If you angle the lens down from the horizon, for instance, you’ll get a definite bow in the horizon.

But this shot was taken with the same setup from the same spot but just centering the horizon vertically in the frame. It’s the mid-point of the distortion so results in an essentially straight horizon.

[before-after viewer_position=”center” orientation=”horizontal” label_position=”one” overlay_color=”#ffffff”  label_color=”#000000″ label_one=”Pointed down, with Fisheye Lens” label_two=”Centered horizon, with Fisheye Lens”]

This shot illustrates two things: how the fisheye distortion can bend horizons and also that while quite sharp in the middle of the frame, things get very soft around the edges.


Using it Out of the Water

It does work well above water, with some caveats that aren’t unexpected. You do lose some sharpness, and the edges of the frame get quite soft. It also accentuates chromatic aberration (purple fringing) (just the basic lens, without the fisheye adapter, does exhibit some purple fringing in some circumstances; the fisheye adapter makes it more prominent and more common).

Using it for Split Over/Under Photos

The front face of the fisheye lens is quite large. That makes it easier to do split over/under photos, where part of the frame is below the water and part is above the water. It’s still a bit tricky–trickier than when using a large dome port, for instance–but it can be done.

One thing I did find though is that it can throw off the camera’s focusing system. So the results can be a bit hit and miss. Here’s an example where the focus got confused.

Another issue I’ve run into is that the extra surfaces add more places for water droplets to stick to and an even shallower depth of field. So it’s pretty easy to end up with water droplets on the glass interfering with your photo.

Notes & Things to Watch Out For

Compatibility. The adapter is compatible with all of Olympus’s TG-X series from TG-1 through TG-5. The packaging has a sticker that says it’s compatible with the TG-3 and TG-4. It’s also compatible with the TG-5, but the packaging materials haven’t yet caught up with the new model.

Using Flash. The lens is large and partially obscures the flash. You can still shoot with the flash, but you’ll end up with a darker part of the frame that’s in the lens’s shadow.

Possible Interference. Some of the camera’s functions, like autofocus, stabilization, and automatic exposure might get a bit thrown off by the lens with inconsistent results.

Smudges and Water Drops. Because the front element of glass is large, flat, and flush with the front, it’s very easy to get finger smudges, sunscreen, and water drops on it. Combined with the very close focusing that the super-wide angle brings, those can easily interfere with the image quality. I found this to be a fairly persistent issue.

Zoom. The camera’s zoom function still works with the lens attached, but in many cases it probably doesn’t make much sense to use it because unless you need the very wide perspective that the fisheye lens gives, you’ll get better quality without the lens attached.


Magnification: 0.74x
Weight: 4.4 ounces / 125 grams
Depth: 1.1 inches / 27.2 mm
Outer Diameter: 2.6 inches / ø65
Waterproof Rating: IPX8 (20 m / 65.6 feet of water for 60 mins according to Olympus in-house testing)
Dustproof Rating: IP6X (Olympus in-house testing)

Where to Buy

You can find them at B&H Photo and Amazon.

Images and product information from Amazon Product Advertising API were last updated on 2019-09-22 at 04:48.

View Comments

  • Nice review. I have a question/problem with the CLA-T01 adapter on a TG-5 camera. When placing it on the camera instead of the supplied protective ring, the locking mechanism seems to work fine, but the adapter ring has some slack, resulting in a circular, back-and-forth rotation of the telephoto or fisheye lenses. I have three adapters and they all behave similarly. Is this normal? Never seen a similar loose fit on SLR camera, and wondering if this is simply how the camera-adapter is configured, or if something is faulty. Thanks for any advice. (Contacted Olympus, but still waiting for a helpful response.)

    • Not sure I can help with that one, sorry. I haven't run into that issue, and I don't have the TG-5 or lens close at hand right now to see if I can replicate the issue. Hope Olympus support can sort it out for you.

  • My TG 5 with the fisheye leaks. I read somewhere that I can let water in and that would eliminate the bubbles. Thoughts?

    • I haven't tried it. Since the lens is entirely external and doesn't impact the camera's own seals, I can't think of a way it might hurt to try.