Thursday, 2 January 2020

Laowa 4mm f/2.8 fisheye: Fun and nice novelty lens

We have been blessed with some small, good and inexpensive fisheye lenses for the Micro Four Thirds format. The Samyang 7.5mm f/3.5 (my review) especially comes to my mind, being a personal favourite for a almost a decade. Another interesting lens has popped up, the Laowa 4mm f/2.8 210° circular fisheye from Venus Optics.

Compared to the Samyang, it is less expensive, smaller in size, wider, faster and in general more exotic. So is it any good? Let's take a look.


The lens is totally mechanical, with no electronic connections at all. You set the aperture and focus manually, just like with all other traditional pre-autofocus lenses. And this works fine! The aperture ring has light clicks on full aperture stops, and has an adequate level of friction so that it doesn't slip when you set it. Despite the clicks, it can still be set easily to intermediate apertures, especially since there is a generous distance between the stops for the largest apertures.

The focus ring is near the mount, and is so narrow that you have to use the finger index piece provided to operate it. The focus ring is nicely dampened, and feels like it is high quality.

The lens has a metal construction, and would appeal to those who like classic mechanical lenses.

It comes with a metal cap, which is held in place with friction. This functions fine, just slip it over the lens, and it is well protected. Be sure not to lose the cap, since sourcing a new one will be somewhat expensive.

The lens is very small. The diameter is smaller than the rear lens cap, as you can see from the picture above. To see just how small it is, compare it with similar circular fisheye lenses:


From left to right: Laowa 4mm f/2.8 on Lumix GX850, Meike 6.5mm f/2 on Sony a5100 and Samyang 8mm f/3.5 on Nikon Z 7.

Lens
Format
Micro Four Thirds
APS-C
Full Format
Field of view
210°
190°
180°
Weight
135g
300g
443g
Diameter
45mm
61mm
75mm
Length
26mm
52mm
77mm
Minimum focus distance
0.08m
0.19m
0.30m




While the size dimensions themselves are impressive for the Laowa 4mm lens, what is especially impressive is the field of view at 210°. In this context, 180° means that the lens pictures everything in front of it, including straight up, down, and to the sides.

210° means that in addition, it also sees backwards, behind you. Lenses that could do this used to be extremely exotic and expensive, like the near mythical Nikon 6mm f/2.8 circular fisheye lens with a 220° field of view from 1972. Not only is it gigantic in size, but also very, very expensive.

The field of view can be illustrated with the green segment in the image below:


To achieve this wideness, an extreme lens design is used:


A side effect is, as you can probably guess already, the lens will also pick up the grip on any camera which has a handle protruding from the body, and, of course, your fingers. That is why the lens is pictured with the handle-less Lumix GX850 above.

Here is what an image looks like when you use the Lumix GH5, notice the grip and fingers on the right hand side of the image:


Also, with the wide field of view, it takes some practice avoiding the inclusion of your feet or head inside the image as well. Generally, you have to hold the camera out in front of you when using the lens.

And as the lens covers more than half of the sphere around you, you should expect to have the sun, or some other bright light, inside the image quite often. Hence, it is important to see how the lens handles strong contrast. Let's compare it with the two others pictured initially (click to see larger versions of the pictures). The sun is in the centre right part of the images, which is a challenging situation for a wide angle lens. All the images were taken at f/5.6:

Laowa 4mm f/2.8 on Lumix GX850:



Meike 6.5mm f/2 on Sony a5100



Samyang 8mm f/3.5 on Nikon Z 7



The first thing to note is the wider field of view of the first two images, compared with the traditional 180° specification of the Samyang lens.

Second, you'll note that there is the most sun flare in the first image taken with the Laowa lens. This is a sign that the optical design is weaker.

We can also compare the sharpness from the centre of the images. I have scaled them so that they have the same resolution:



And from the right hand side:



Now, it is difficult to compare these. Of course, the cameras have quite different resolutions: 16MP (Lumix GX850), 24MP (Sony a5100), and 45MP (Nikon Z 7). So when scaled to the same resolution, the two latter benefit from having more usable pixels.

The Lumix image is also somewhat less exposed. Still, it is apparent that the usable sharpness is lower on the Laowa 4mm f/2.8. But this is not a deal breaker: With some sharpening applied in post it would look quite good, and notice that the lens retains quite good sharpness off-centre, compared with the peer lenses. So the Laowa fares quite good in this test.

Video


As for the use in video, the lens is somewhat challenging. Only a few Micro Four Thirds cameras can record video from the whole sensor in 4:3 mode, which is required to catch the whole circular fisheye image. The Lumix GH5 can do this.

Other cameras can only record video in 16:9 mode, which will strip the top and bottom ends off the circular image, which is not very useful. Hence, there is currently no M4/3 camera which can record clean video off the whole image circle, without also showing the camera grip in the video.

Here is what it looks like with the Lumix GH5 in 4:3 mode. Note the camera grip is visible on the right hand side:



Compared with the Samyang 7.5mm f/3.5 fisheye


Regular readers will know that the Samyang 7.5mm f/3.5 (my review) is one of my favourite lenses. It is one of the Micro Four Thirds lenses I have used the most for the last decade. So how does it compare with the Laowa 4mm circular fisheye lens?



Laowa 4mm f/2.8 210° circular fisheye (left), Samyang 7.5mm f/3.5 fullframe fisheye (right)

First off, what properties do they share? Both are fully manual lenses, requiring you to set the focus and aperture manually. Also, both are third party lenses, designed by others than those who own the format, trying to capitalize on the popularity of Micro Four Thirds.

And both are fisheye lenses, but in different ways. The Laowa is a circular fisheye lens, meaning that it projects everything within the 210° field of view into a circle in the middle of the sensor plane. Everything outside of this circle is black.

The Samyang, on the other hand, is a full frame fisheye lens. It covers an equally impressive 180° field of view, but only diagonally across the full sensor frame. Horizontally and vertically, it covers a smaller angle of view. So the disadvantage is that it doesn't cover as much of the field of view, but the advantage is that it uses the sensor more efficiently: All of the sensor frame is used. The two types are illustrated here. While most fisheye lenses have a 180° coverage, keep in mind that for the Laowa lens it is 210°:



This makes images coming from the Samyang lens more easy to use: People are more used to seeing rectangular images, as opposed to circular images. Also, video will look good, both in 4:3 and the more common 16:9 format.

The differences can be illustrated with some example images, all taken at f/5.6. Click to enlarge them:






Optically, I would rate the Samyang lens somewhat better. But the Laowa lens performs quite well here, and you'll see that there isn't a lot of flare issues in the high contrast night shots. So both lenses should give you good results.

Regarding the different approaches (circular vs full frame fisheye): I think that if you want one fisheye lens to cover your extreme wide angle needs, the easy choice is the Samyang 7.5mm f/3.5. This lens will give you images straight out of the camera which are interesting and useful, even without any post process defishing, e.g., using the free software Hugin.

On the other hand, the Laowa 4mm f/2.8 is more extreme and has a higher novelty factor, for better and for worse. This lens can give you truly unique images, but to make them useful, you may need to work a bit harder both taking the images in the first place, and on post processing.

Conclusion


The Laowa 4mm f/2.8 210° circular fisheye lens is inexpensive, small, well made, and optically competent, but not perfect. If you would like to have a fun novelty lens for some occasional extremely wide images, then this is a good choice: There is hardly any lens available which is wider, and it is a good quality lens to boot.

Don't be intimidated by the manual focus. If you are taking a scenery shot in good light, just set the aperture to f/5.6, and the focus ring near infinity, and everything is well in focus. If you want to take a closeup picture, to focus correctly can be a bit more tricky, but with some practice this should just take some extra seconds with the nice focus peaking tools that most cameras have.



Example images


Click to enlarge:







By using the Hugin software to defish the images, you can get images like these:






2 comments:

  1. This lens also just released for e-mount aps-c. I wonder what the field view is.

    ReplyDelete
    Replies
    1. The whole image circle is supported by both formats. So the field of view is exactly the same on Four Thirds and APS-C: It is 210°.

      Crop factor is not relevant between these two formats due to the special projection.

      Delete