The challenge with diopters is getting a sharp image while maximising depth-of-field and limiting edge distortion. The latter is a real issue when shooting at wider angles. Compared to lenses such as the Inon UCL-165 (RRP AU$249), and the DYRON Macro lens UCL67II (RRP $199), the Fantasea UCL-05LF 6 Macro Lens (RRP AU$309) is a far superior option. Here is my review of the of Fantasea UCL-05LF 6 macro lens on a Fantasea Housing for Sony RX100 III IV V and VA. For the sake of this review, I’m mostly going to compare the Inon with the Fantasea lens.
Overview
The main difference between the three lenses is that the Fantasea UCL-05LF 6 has four elements, while the others have two. It’s heavier but the lens construction this makes all the difference. It’s also a longer lens, which you have to bear in mind when using your zoom or stacking onto other lenses (I’ll come back to that at the end).
Sharpness
The difference in sharpness is profound, illustrated by these images of a seastar’s madreporite at about 400% zoom. The Fantasea UCL-05LF 6 is a lot sharper.
Focus distance – maximum
The advantage of diopters is you can carry a wide angle lens for the ‘big stuff’ and swap out lenses whenever you need macro. This level of versatilty is unrivaled in conventional underwater camera set ups. It does come with some drawbacks however. Then again, every camera setup has limits, so it’s just a matter of working to them.
With macro lenses, you have a minimum and a maximum focus distance. There is no ‘infinity’ which means your background will always be blurred. On the one hand, you need to be close enough to the subject for it to be in focus and on the other hand, not too close. While most reviews concentrate on the near-distance, it’s the maximum that I find more limiting. Especially when you’re trying to capture pictures of small fish like blennies, triple-fins and gobies. They simply swim away when you get to about 10cm from them.
Here is a table that summarises the maximum focus distance for three lenses. Note, this experiment was done above water. Because of light refraction differences, any similar measuresments in this review are only as a guide. Underwater the results will be different but it shows clearly that the Fantasea allows for more distant focusing.
| ModelThe process, either mathematically or in the human brain, of creating an internal version of something that we can refer to, to better understand how it functions and our place within. Scientific modelling is where we take the best knowledge we have and build a version of what will happen, if we assume certain parameters. For example, we might model More | Zoom | Focus | Distance | Limit |
| DYNON +6 | Full wide | Infinity | 90mm | Maximum |
| Inon UCL-165 | Full wide | Infinity | 120mm | Maximum |
| Fantasea UCL-05LF 6 | 50mm | Infinity | 150mm | Maximum |
Distortion
Distortion is a huge limitation on the DYRON and Inon lenses. There aren’t enough glass elements to smooth out the borders so particularly at wide angle, this upsets the picture.
For example, in this image of a Ghost Pipefish taken with the DYRON Macro lens UCL67II, a significant proportion of the image is distorted, to the extent that most of the fish is out of focus, despite the central portion being sharp. I’ll refer to this image again later in regards to Bokeh (pronounced bo-keh). This is the aesthetic quality of blurred areas e.g. the tail in the bottom left.
At wide angle
To illustrate distortion, I lined up the three lenses. At full wide angle and maximum focus distance, the distortion of the DYRON and Inon are notable, especially due to the necessity of being very close to the subject. The Fantasea lens is unusable at wide angle due to vignetting and has to be zoomed in to 50mm. Each square is 1.5 x 15 cm.
At half zoom
For comparison, here are the three lenses at 50mm. Due to the close focusing distance, the DYRON is restricted to subjects that are less than about 6cm wide. The Inon has a slightly wider field of view but there is distinct distortion at the edges. While the Fantasea is much wider (11.5cm) and almost perfectly flat. Any slight distortion can easily be corrected applying a slight lens distortion correction in Lightroom (which is common for all standard lenses).
The following two images show the difference between the Inon and Fantasea in the field underwater.
The wider angle of the Fantasea is apparent. Though there is some distortion, this is marginal when compared to the Inon lens.
Focus distance – minimum + depth-of-field
A quick mention of minimum distance. This is a consideration as the Fantasea does not focus as closely as the other two lenses. In my opinion, the versatility it provides at the greater distances, more than compensates. I also carry a +15 Fantasea lens for the real close up work and I can also add the lenses together (see below).
It’s hard to compare these lenses in terms of depth of field. Because the Fantasea lens doesn’t operate as close. I like to photograph with a narrow depth of field as it looks more aesthetically pleasing. Sometimes I need to vary this though. So to have a lens with a slightly wider depth of field, especially for larger subjects, is useful.
I did very basis assessment above water with the three lenses (above). At the closest setting and narrowest aperture (f11), the DYRON and Inon both had an in-focus range of about ± 2.5mm from the point of focus. The Fantasea was about ± 7mm. This suggests that it’s going to be easier to get whole subjects in focus, especially at wider angles.
Bokeh
The general aesthetic of blurred areas of an image are of great importance. It will take some time for me to understand this as I need to use the Fantasea lens more frequently. Initial results, however, look good.
Here are four photos I took on my foray. Immediately the images look crisper, the blurring is neat and pleasing to the eye, and they look flat and indistorted. Result!
Stacking lenses
One final thing to add. You can stack these lens as they have both front and rear 67mm threads. You have to expect some deterioration in quality but it’s still quite impressive.
Here is a photo taken of the blue madreporite organ on the same seastar from the images immediately above. In this I stacked the Fantasea UCL-05LF 6 on top of the Fantasea UCL-900F 15 Super Macro Lens. Unfortunately, this website compresses photos slightly, so the crispness of the image isn’t fully represented, so I’ve copied a cropped section below.
Summary
In summary, the Fantasea enables a far greater versatlity when coupled with other lenses. Compared to the slightly cheaper alternatives, it has a wider angle. But I think most photographers would prefer this. Many’s a time I’ve wished I could zoom a bit more wide angle and maintain a flat perspective. This image offers this.
Overall this lens is far superior. It’s sharper with a wider depth of field, a flat image with minimal distortion and a longer maximum focus distance (which means being able to photograph small fish more easily).
The right camera for you – get advice!
Call the team at https://underwater.com.au/ who will be able to advise you on the best starting point for you. They are highly respected and extremely knowledgeable.
