Olympus 9mm f/8 fisheye review

The Olympus 9mm f/8 fisheye is the second in the series of non-Zuiko branded "toy" body lens cap lenses. The first was the Olympus 15mm f/8. Both are very compact lenses, with a fixed f/8 aperture, and a small lever which operates a lens cap, and the focus.

Here is the 9mm fisheye lens, with the supplied rear lens cap. The lens comes in a simple cardboard box, padded with a bubble wrap bag:

Physical and in use

The lens is very light, and is made from a hard plastic material. Turning the lever on the front opens up the front lens cover, exposing the lens. Turning it further controls the focus. There are two "click stops" on the focus scale: One for "infinity", and one dot for "distant" focus, as explained in the manual. These two are quite similar in terms of focus distance.

I would advice to use the "infinity" stop if you have no foreground items, and the second dot stop if you have some foreground objects. For focus closer than about 1 meter, you should start turning the lever closer to 0.2m.

The lever is quite loose, and you easily risk knocking it out of place accidentally. If you change the focus, you'll see that the whole lens assembly moves back and forth. So this lens does not have an internal focus, is has a classic focus mechanism.

On the rear side, you see that the exit pupil is much larger than the front entry pupil. This is probably to make the lens sufficiently telecentric, so that the light rays do not reach the sensor corners at a too steep angle.

There is no serial number on the lens, and no electronic contacts. So to use the lens, you need to enable the "Shoot without lens" option, which tells the camera to allow taking pictures, even if it does not sense any electronic lens being present.

The camera will still store EXIF data in your image files, however, the information about focal length and aperture is never passed to the camera, and will be missing when using this lens.

The lens is a good match for the compact Lumix GM1 camera, making it truly pocketable:

The max aperture is f/8, which does not sound very impressive. However, for daylight use, this is perfectly fine, no problem at all. For indoor use, though, f/8 can be too dim. So indoors, you may need to use a flash.

Image quality

To check the image quality, it is a good idea to compare it with its peers. Below it is seen with the Wanderlust Pinwide pinhole (my review) and the Samyang 7.5mm f/3.5 fisheye lens (my review):

The Wanderlust Pinwide pinhole is similar in the sense that it is also a "fun novelty item", and is very compact, and wide. The Samyang 7.5mm f/3.5 fisheye lens is a very good fisheye lens at a reasonable price, one of the real bargains of the Micro Four Thirds system.

Here is the same building photographed with the three lenses (click for larger images):

Wanderlust Pinwide	Olympus 9mm f/8 fisheye	Samyang 7.5mm f/3.5

From these images, you clearly see that the Olympus 9mm f/8 fisheye is not a true fisheye lens: It doesn't have a full 180° diagonal field of view. The diagonal field of view is about 140°.

Further, we also see that the Samyang 7.5mm f/3.5 is way better in terms of image quality. Here are some 100% crops to illustrate this. From the centre:

And from the lower left corner:

In the centre, the Olympus 9mm f/8 fisheye is quite sharp indeed. However, in the corners, the sharpness is rather poor. But all in all, the lens is certainly fully usable.

With a wide lens, you will often experience to have the sun inside the frame. Hence, it is important that the lens handles flare well. Here's how it does:

As you see, there is quite some flare, but it is not too bad. The flare looks quite ok, and even charming, one might say.

Lens	Olympus 9mm f/8 fisheye	Samyang 7.5mm f/3.5 fisheye
Weight	30g	197g
Diameter	56mm	60mm
Length	13mm	48mm
Lenses/Groups	5/4	9/7
Minimum focus	0.20m	0.09m

The lens has a quite close minimum focus distance: 0.2m. In this example, I have the corner of the traffic sign about 3cm from the front of the lens, with the focus set to the minimum:

Here, the focus is set to infinity:

Looking at the top left corner, we see that there are quite some chromatic aberration artefacts in the corners, click for a larger image:

Alternative lens

Beyond the Samyang 7.5mm fisheye, also marketed as Bower, Rokinon, there is the Lumix G 8mm f/3.5 fisheye (my review). It is seen below, together with the Olympus fisheye lens:

Olympus 9mm f/8 (left) and Lumix G 8mm f/3.5 (right)

Except for the fact that both lenses are very wide and have a significant barrel distortion, they are very different. The Lumix G 8mm is quite expensive, around US$700.

The Lumix lens has autofocus. However, the autofocus is normally not needed for a wide fisheye lens. Autofocus can come in handy if you are making cute closeup pictures of pets, but otherwise, it is not a big deal.

The Lumix lens has a full 180° diagonal field of view. In terms of image quality, it is not quite as good as the much cheaper Samyang lens, according to my comparison. Also, the Lumix lens has slightly more barrel distortion, see a comparison here. To top it off, I also find that the Samyang is less susceptible to flare. This makes the Samyang lens a good deal, and the Lumix lens less so.

Defishing

Using free software, it is easy to "defish" the fisheye images, i.e., removing the barrel distortion. See an example here, including a comparison with an image taken at 9mm with the 9-18mm wide zoom lens.

Conclusion

The Olympus 9mm f/8 fisheye is certainly an interesting lens. Mostly, it is interesting due to the size: It makes your camera very compact indeed.

Optically, the image quality is ok, but hardly impressive. If you seriously want to test a fisheye lens, then I would wholeheartedly recommend the Samyang 7.5mm f/3.5 fisheye lens (my review), which has a much wider field of view, very good optical properties, and is easy and fun to use.

The Olympus 9mm f/8 fisheye still has its place, as a fun, cheap, novelty lens, which takes good images. It is not a toy lens, I would say. It has normal glass lens elements, and two of them even have aspherical surfaces.

Example images

These are JPEG images straight out of the camera, the Lumix GH4. Click for larger images.

f/8, 1/160s, ISO 800:

f/8, 1/125s, ISO 200:

Example video

Here is a video recorded with the Lumix GH4. The first segment is done using 1080p, and the second at 4k resolution. With the extra 4k crop, the 9mm lens becomes a reasonably wide, almost rectilinear lens. In 4k resolution on the Lumix GH4, you barely see that there is barrel distortion, due to the camera cropping off the border.