Category Archives: Fisheye lens

Red Sea Workshop with Alex Mustard – Part IV Shark Reef

After the first 3 days of workshop we got into the core of it and Alex talked about schooling fish and how to take shots.

We had 4-5 varieties to choose from:

  • Batfish
  • Surgeonfish
  • Barracuda
  • Jacks
  • Snappers

Detailed information was given in terms of how to best approach the fish depending on their behavior and also about the etiquette in terms of letting other people best positioned taking their shot first.

The surgeon fish are not that photogenic and actually quite messy I tried to take some shots when the current was pumping and they were all aligned close to the bottom at Yolanda however to me this is not that exciting as a shot. Other people got better results but I frankly was not that bothered about Surgeons. Probably as the fish is pretty dark and does not reflect the strobe much. The featured image close to the title shows what I mean.

During this trip the current was not going north to south as usual but there was near to no current at shark reef and current going outward at yolanda corner. This means the snappers that usually sit at the edge of shark reef were not out to play.

We were left with barracuda, batfish and jacks to choose from. On day 4 I only see few giant trevally but not many schooling jacks so had to focus on barracuda and batfish.

Unfortunately the barracuda were far from the reef and a bit too deep and did not really want to entertain chasing them so I tried with the batfish. Obviously there were not only us but also other boats so it was a bit of a competition for fish.

Encirclement
Encirclement

Also you always managed to get someone in the frame or bubbles

Shooting Batfish Below
Shooting Batfish Below

So I focused on trying to get the best backgrounds for the pictures to come like in this case.

Bommie

Also had some fun taking images of the others and the batfish one or two came out pretty good.

Bats Photography

Creative angles
Creative angles

It is quite hard to have the discipline to respect rules when you are with other 18 photographer on the boat so the competitions had to be expected and I was not that bothered.

In the evening we headed back to Ras Katy and I borrowed a Nikon D7100 from Nauticam UK. I asked to have a 9″ dome for the split shot and jumped in the water with the idea of just doing that.

This is my best  shot

Ras Katy Sunset

Personally I do not like split shots where the surface line is very distorted to avoid that you need to make sure your lens is near to rectilinear and it is better to shoot portrait as there is little distortion on that axis. What I wanted to capture in this shot is layers, the reef, water under and over, the boat and sunset colors.

I think it came out pretty good but it is painful to take 100 shots just to get one right and I wish I had some fish in the frame but never mind is good enough like this. The water was not really flat so that was an additional challenge as you can see the wave breaks on the lens creating a little thicker line but overall a good shot.

 

Sony RX100 Mark III – Is it worth upgrading?

UPDATED 23 July 2014

Once again Sony has updated their RX100 camera with a stunning new release that will surely be a market leader at least until the release of the new promised Panasonic large compact sensor with 4K video recording.

So the question is again is it worth throwing our hard-earned money to this new model and housing or should we stay with what we have got? The Mark I and II are still available at reduced price though it is becoming harder to find Mark I housing as new.

The answer to the question is: it depends on what you are planning to do with your RX100, for some users an upgrade may not be required or even not advised let’s see why. no don’t waste any time with the Mark III.

Every time a new camera is released and reviewed I get a bunch of emails with subject: New Camera XYZ what do you think?

The best reviews you find online are made by sites that specialize in land photography and no consideration is given to underwater use. So not necessarily a camera that is a top performer on land will remain such underwater as this depends on specific characteristics that may be different or even opposite to land requirements.

So those reviews cannot be taken as they are they need interpretation. Personally I use two sites for camera reviews imaging resource and dxo mark I use the first to understand ergonomics, performance and to compare images with other cameras side to side, and the second to check sensor quality and lenses. Imaging resource has made a good article to compare the various RX100 on land read it here

http://www.imaging-resource.com/news/2014/06/16/battle-of-the-rx100s-sonys-rx100-vs-rx100-ii-vs-rx100-iii

If you look at a sensor comparison on DXOMark you would conclude that there is no need to upgrade at all if you use your camera primarily for still pictures as the sensor are practically identical in performance as this table demonstrates:

RX100 Sensor Ratings
RX100 Sensor Ratings

As you can see the differences in dynamic range, color depth or ISO are pretty much intangible.

However there are other metrics that are also important let’s see which ones and why.

Flash Recycling

We want our camera on board flash to recycle quickly after a full dump as the RX100 has only TTL flash and the flash can’t set to a minimum manual setting without consequences. Those are the flash recycling times at full output (a full dump will always occur when you don’t aim strobes directly at the subject for example wide angle)

Mark I: 7.2 seconds

Mark II” 4.4 seconds

Mark III: 3.3 seconds

The Mark III is pretty quick and the Mark II is acceptable the first release is definitely too slow.

Minimum Capture Area & Zoom

What is the smallest area that can be captured at wide end at the closest focus distance? This gives you an idea of out of the box close up performance

I do not have precise metrics yet but looking at comparable images on imaging-resource seems like the Mark III is worse than the Mark I and II of at least 20% with a capture width around 90mm versus the already not very good 76mm of the Mark I and II.

To fix this issue we use close up lenses in water that fix to a great extent the focal length and then zoom in to achieve magnification which means longer camera lens more magnification I roughly estimate that the Mark III will be worse of a factor of 0.7x so things will look 1.4x bigger with the Mark III this is terrible news for macro shooters as it means you need to be on top of the subject to fill the frame, this is in some cases not possible.

I have estimated that you need 11 diopters to achieve 1:1 macro so the Subsee 10 and Inon UCL100 that gave real macro on the Mark I and II won’t be sufficient. With two UCL-165 or Dyron 7 you are looking at 2.58″ or 6.5 cm from the back of the first close up lens that means you will be right on top of the subject which is not really an option.

Update July 18th: Nauticam has confirmed that even with their SMC lens the most powerful diopter on the market the capture area is 38mm wide so does NOT achieve 1:1 macro as I suggested…

 

Lens Focal Range

The new mark III has a 24-70mm lens compared to the 28-100mm of the Mark I and II what does this mean?

  • Less magnification with close up lenses and no real 1:1 macro
  • Vignetting or even not possible to use fisheye lenses designed for 28mm lenses

This means that with the Mark III your scene selection will be restricted  compared to the 150 to 24 of the mark I and II.

Update 23 July I have done some tests that confirm my suspicions please look at the following frames. The Mark III once zoom to 28mm actually works fine with the Mark II housing except the power button.

RX100 Mark III with Inon UCL-165 Close up lens
RX100 Mark III with Inon UCL-165 Close up lens

With a single Inon UCL-165 (+6.06 in water) the minimum capture area width is 5.4 cm which is bigger than the Mark II 4.8 cm. Not only that the distance from the top of the lens is only 9cm.

With stacked UCL-165+UCL330 total power 9.09 diopter we get this

Stacked UCL-165+UCL330
Stacked UCL-165+UCL330

4.4 cm width however we start running into problems as the minimum distance from the lens is only 4cm.

We finally achieve 1:1 with two stacked UCL-165 however the distance from the top of the lens is 3cm definitely too little

two UCL-165 stacked
two UCL-165 stacked

I have also tried the Mark III at 28mm and it still vignettes with the Inon UWL-H100 in air until around 30mm. Instead the old UWL-100 28AD is fine at 28mm either way image looks narrower than with the Mark II but this may be an issue with the old housing.

So basically no macro with the Mark III and no decent fisheye as expected.

Underwater Photography Conclusion

Due to the reasons above the best camera for the job is the RX100 Mark II, with the Mark I coming close but being penalized by the strobe recycle time, the Mark III really is not an option for the serious shooter due to limitations of the lens.

Let’s have a look at some other features of the Mark III that are not relevant for stills as much as they are for video.

ND filter

Shooting at the surface with plenty of ambient light or on land can create problems if you want to follow the 180 shutter rule, the ND filter of the Mark III ensures your footage will be smooth on land and in water. Take into account that on land you can apply optical ND filters (I have it for the Mark II) so this is really for underwater use when you are shooting at 1/50 or 1/60 shutter speed and the scene is too bright when you hit f/11 and the lowest possible ISO. Having now tested this feature I confirm it is really valid on land on a bright day to keep the aperture wide.

Clear Image Zoom

This is a special digital zoom with edge enhancement that only worked on JPEG stills on Mark I and II but is now available on video on the mark III. This means an additional 2x zoom is available bringing the focal length to 140mm that is more than adequate for macro. This is not an option on RAW images so irrelevant for still users.

23 July update Having done some tests for macro video (as stacking two diopters is not an option) the image quality suffers but anyway this is all you are left with lacking any other options.

Clear image zoom 1.5x on single UCL-165
Clear image zoom 1.5x on single UCL-165

Image stabilizer

The Mark III adds a further stabilizer mode with additional crop that takes the lens to 96mm equivalent in video mode. This is well worth for super macro hand-held footage and effectively provides an option where you can either use the super steady shot and no clear image zoom when hand-held or leave on only the optical stabilizer and use clear image zoom. If you shoot macro on walls and not on flat sand this is a well worth feature.

Update 23 July 2014

Following a side by side comparison you can find on this link

It follows that there is really no 5 axis stabilisation and only an additional mode with more crop with correction for rolling shutter that anyway does not really work!

Full Sensor Readout Video

The mark III reads the whole sensor not just alternate lines when capturing video this increases should increase the resolution to a great degree and increases the perceived resolution and clarity of your videos. However this does not seem to correspond to real life tests. See this sample with a side by side comparison the Mark III looks visibly worse than its predecessor even on the higher bitrate XAVC!!!

Video Formats

The Mark II introduced a well welcomes 24 Mbps 24/25 fps mode now the Mark III introduces a 50 Mbps mode in XAVC (that can be rewrapped into normal MP4) that produces even better footage although it will be quite demanding on your workstation and most likely some of your home devices will struggle playing the files (my Apple Tv 3rd generation only plays up to 25 Mbps) when uploading files online this will downgrade to 8 Mbps so won’t matter unless you have a good player at home. improves nothing and requires manipulation as the files are actually not MP4 compliant as they have WAV audio (!) they are also inside the AVCHD folder which is painful. As seen above seems like the encoding has got worse on the AVCHD files and only the higher bitrate compares but still does not match the mark II at the lower 24 Mbps!!!

HDMI connection

You can now connect the Mark III to an external HDMI recorder if you are into that kind of semi pro usage. For the normal user this is not relevant: if you are into spending that money probably you have already a DSLR or a Panasonic GH4.

Video Auto Focus

The auto focus in video has got worse you can see an example in the stabiliser test, and actually plenty of frames are blurred on the mark III. Awful!

Underwater Video Conclusion

The Mark I with only a 28 Mbps 50/60p mode is definitely a poor choice, the Mark II is acceptable to most users. and the mark III promises even better performance if you are a serious video user and have another camera to take pictures the Mark III may be well worth it.

The Mark III despite some useful feature is actually a let down and perform worse in practical terms than the mark II that remains my camera of choice.

Summary

If you have a Mark I camera and are frustrated with flash recycling you should be looking at a cheaper upgrade to the Mark II.

If you have a Mark II and your priority is photography upgrading is NOT recommended.

If you don’t have any RX100 get yourself a Mark II or wait for the new Panasonic as the Mark III is pretty much a pile of crap.

Is it the first time I am actually sending back a camera and invoking consumer rights but when I spoke to the camera shop they told me they had other returns and this is not really an upgrade!!!

Look Right inThe above image was shot at 100mm equivalent with one diopter with the RX100 Mark II. You won’t be able to fill the frame with the same close up lens and the Mark III camera

Red Sea Workshop with Alex Mustard – Part III Sunbursts and the Caves

On the early morning of Day 3 we left the Thistlegorm for Ras Mohammed.

Dive number one would have been on Ras Zahatar, this dive site has some great opportunities for sunburst shots in the early morning but generally not a lot of fish as the location is quite sheltered and there is never too much current that I recall.

There are also some very nice gorgonian fans around the 22 meters mark however as soon as we jumped in it was clear it was going to be a competition to have some of it. Besides not having made clear arrangements for modelling with anyone it was going to be a quite technical session.

Since the arrival of digital sunburst shots have proven to be problematic for DSLR and mirrorless users. The issue is with the sunball itself there is an issue of highlights when you try to shoot a coral reef with the sunball in the frame and you are using a shutter speed of 1/250th or 1/320th that are typical DSLR sync speed.

Mirrorless cameras do even worst as usually the base ISO starts at 200 that makes it really difficult to capture this shot.

So the key is to put the sun behind something or have the rays in the frame but not the sunball. Something like this to give an idea

Soft Coral
The sunball just behind the soft coral gives a nice glow so even with a 1/250th shutter and f/8 at ISO 100 is possible to capture a captivating scene.

Few meters away there is a gorgonian with a red soft coral on top that is really exciting to see at naked eye. To me this reminds of a frogfish head profile. It is impossible to capture this scene at 1/250th f/11 ISO 100 it is just too bright you need to reduce at least two stops to get the sun properly however if you did that on a DSLR you would be shooting at f/22 and it is near to impossible to properly illuminate the coral with your strobes at the distance required.

That is where our RX100 compact comes to help as you can sync your strobes at 1/2000th this should give a black background around the coral, the coral properly lit in the foreground as I had the strobes at full power and the sunball in the frame as well without too  many glowing highlights, this is the resulting shot
Sunburst
Note that a model would not be visible in this shot and fish would be colorful only in front of the coral or close by anyway as discussed there was not fish to model for me and this was just technical entertainment. The image is quite strong but the lack of fish makes it less interesting.

I found some cooperating clown fish on this dive however they are those with the dark eyes so despite the eye contact the shot is not as strong as it would be with a better subject
Look Right in
This is taken with a single Inon UCL-165 a luxury of having a compact and being able to wide and macro on the same dive.

Anyway I was happy with the sunburst in the frame so that dive was well worth it.

Dive two was at Jackfish Alley, and proved to be the most entertaining of the day. Who knows this dive sites knows that there are two caves, the first is wide but very dark and at certain times has turtles inside. The second is really narrow but has few cracks the provides a cathedral light effect best experienced in other site of the Southern Red Sea. Anyway we got the briefing and Dr Mustard was going to be marshaling the queue of photographer in cave number 2.

Being familiar with the dive site I knew that cave 2 is quite narrow even for normal diver let alone this big troupe of photographer so I mounted my tripod legs on the tray with a view of working in cave 1 and then move to cave 2 after the chaos was over.

Well it was real chaos as you can see from the feature image divers in the way, bubbles silt, in short it was a mess.

So I spent some time in cave number 1, this cave is really dark and you can’t really shoot handheld. In cave number 2 you can use speeds of 1/25 or 1/30 up your ISO  and put the camera on a rock whilst you take the shot, in cave 1 this results in darkness unless you go to 4 digits ISO.

So my shot on cave 1 is taken at 0.4″ f/4 ISO100.
1st Cave@Jackfish Alley
The shot is taken with the camera on the tripod using self shoot so that there is no shake from the hand pressing the shutter, this means the picture is sharp as it can be and due to low ISO also very noise free. Unfortunately fish did not feature in the shot so this is again a fairly technical shot that is not as strong as it could be.

There were other interesting opportunities in smaller cracks like this one that I like quite a lot though is not a sensational shot.
Window
I like the fact that the two snappers are one silhouette and the other full color.

After the shambles of dive 2 we moved to Shark Reef where the first dive was really more to acclimatise with the site so won’t bore you with the pictures for that dive.

In the evening the sunset dive was at Ras Katy that would have been our regular evening spot from there onwards.

On day one I was playing with dapple light and reflections

Dapple at Ras Katy
Dapple at Ras Katy

 

This is me taking the shot above

Interceptor Shooting Dapple

As you can see I am nearly at the surface thanks to Damo for this picture.

Near surface can also be interesting like in this case

Test Shots dapple Reflections
Test Shots dapple Reflections

Here you can see part of the Snell windows together with the reef and the sunball. This shot can be made much more interesting if you focus on the reflections.

Anyway this was the end of day 3 of diving next post will be about Shark Reef and the schools of fish.

Tuition Day with Martin Edge

During the London Dive Show I attended a talk from Martin where he covered a number of shooting situations and how to deal with them in terms of composition and settings.

There was a promotion for a two for one tuition day with him that my buddy was keen to take so few months later we made our way to Dorset for a day of underwater photography with Martin.

This will be my first day of shooting with the RX100 Mark II albeit in a pool with my new arms and lenses so I was looking forward to it.

We arrived in Poole the night before and got ready for an 8.30 start with Martin.

We started off with a review of some basic exposure concepts and then looked at competition winning pictures and trying to identify what makes a wow picture. It was extremely useful!

Afterwards we went through our trips pictures so he could see what needed improving. Then look at what was needed for the next trip.

With that in mind we set up to jump in the pool to take some pictures the objective was to improve my buddy close ups and portraits as apparently her wide angle is as good as it gets with the Canon S95 used see featured image on this post.

Pool conditions were low visibility and plenty of suspended particles as the pool is used for kids swimming lessons let me give you an idea!

Pool Conditions
Pool Conditions

The first task was to shoot a frog with a view of eliminating shadows in its mouth. Start with one strobe and finish off with two.

Frog at 28mm
Frog at 28mm

The frog with the bare port gives you an idea of the size and the complexity of the task with one strobe. There are shadows in his mouth.

Frog at 50mm
Frog at 50mm

I then shot a portrait at 50mm, the reason why you see shadows more on the left is because I set the strobe at different powers.

Frog single diopter
Frog single diopter

The magnification of the RX100 is little so I went on with a first Inon UCL-165 and full zoom at 100mm equivalent. Note that everything is pretty much sharp at f/11.

Frog Double Diopter
Frog Double Diopter

With two Inon UCL-165 focusing on the mouth will result in this and the eyes being in focus and the rest blurred because of lack of depth of field.

Octopus fisheye
Octopus fisheye

I then moved to an Octopus rich of textures. I took the first shot with my Inon UWL-100 28AD with dome.

Octopus at 28mm
Octopus at 28mm

The same octo at 28mm fills the frame much more of course.

Octopus at 50mm
Octopus at 50mm

The Octopus at 50mm looks even better. I have topped up the lighting on this one.

Octopus single diopter
Octopus single diopter

I then took this guy with a single UCL-165 note the depth of field insufficient to keep the back of the head in focus, results though are exceptional.

Octopus double diopter
Octopus double diopter

With two close up lenses we go back to the depth of field problem even at f/11.

I thought I had at that point nailed all focus and strobe issues, especially considering I shot with single auto focus, I did not bother using manual focus at all with exception of some double diopter shots.

I then tried a few surface reflections with the fisheye this being the best.

Falcon Fisheye
Falcon Fisheye

You can see the outside of the pool and the windows on the top.

Family Fisheye
Family Fisheye

Afterwards made my own composition of statues for a fisheye shot that I think came out very well. The Z240 performed extremely well in both TTL and external auto as well as manual.

Child with dog
Child with dog

Martin asked me to have a go at the child with the dog as it is extremely difficult to lit up properly.

I went for an alternative strobe placement with light from the bottom as if it was in a gallery. He was impressed with the results.

Lion Mouth Single Diopter
Lion Mouth Single Diopter

To finish off my last task was the tongue and eyes of a lion that I shot with a single UCL-165.

Overall a great day and I definitely recommend you the tuition day with Martin. He is a great person and extremely good at teaching I can see the benefits my buddy had right away.

Lessons learned on the RX100

There were a few things that I learned about my RX100 still rig mode that I want to share with you.

  • The autofocus is incredible. I even used this for macro. If the camera does not focus is because you don’t have enough depth of field and that is it.
  • Best macro performance is with a single diopter and also had a benefit of an increased working distance, this means the shots will need cropping for extremely small critters
  • Two diopters resulted in near bokeh with less than 1mm in focus and difficult to autofocus (though the LCD is great and I could see if things were in focus or not I think this is personal and I would recommend DMF to others)
  • Performance at wide angle with the UWL-100 28AD with dome is stellar
  • Inon float arms (I used two 6″ segments) were perfect with lens holders on it.
  • Inon Z240 twin set with one in TTL and the second in external auto delivered creative lighting without headaches, remember to buy the AUTO diffuser that does not come with the strobe
  • Strobes in manual allowed for even more creativity and the level of precision compared to sea and sea was staggering
  • Despite pool conditions the RX100 focused well in low light and much better than the Canon S95 that was returning focus error on the same exposures. I will not bother having a focus light with this camera and only have a single sola on night dives

That’s all for now any question just drop a comment

 

Which Fisheye Lens for the RX100?

Recently I have started building my RX100 Mark II photo rig and as part of this I had to choose a wet fisheye lens.

For video I do not like the barrel distortion of a fisheye lens, and on top of that you can’t attach a push on filter to a dome so for me those are two big no when it comes to the RX100 and its white balance error woes.

For still instead I shoot only RAW never white balance in the water and a fisheye lens is required so that I can have human size strobe arms when shooting close focus wide angle at distances between 0 and 16”.

I will focus my discussion on the Nauticam housing starting off with a 67mm thread and go from there.

Currently there are 3 options on the market for the RX100 and come from 3 difference manufacturers. I will go through each one briefly and then we will look more in detail at the two I consider best.

The first lens is the FIX UWL-28M52R, this lens is the smallest of all and was originally design to nicely complement the form factor of a Canon S100 in a fix housing, hence the 52mm thread. The lens has a magnification factor of 0.41x and a diameter of 126mm including the hood, the lens is actually much smaller at around 90mm.

Fix has introduced this lens in 2011 as a replacement of the previous UWL-04 model for two reasons, the first is to have a smaller lens as the UWL-04 was a too big in comparison of the housing, second probably cost though this was never declared. However other people tests and plenty of in water images show that this lens is actually worse than its predecessor. It is also smaller making split over-under shots more difficult.

When Fix withdraw the UWL-04 the manufacturer of the lens continued the production and finally put it back on the market under the i-divesite brand. This lens is the same as the Fix except the label.

Both lenses the old and new fix are pretty much a copy of the old Inon UFL-165, both made of 4 glass elements and an acrylic dome with hard anti scratch coating.

Here is a set of shots for the UWL-04 and the various parts in the box.

UWL-04 Box
UWL-04 Box
UWL-04 package contents
UWL-04 package contents
UWL-04 Hood Cover
UWL-04 Hood Cover
UWL-04 with ring
UWL-04 with ring
UWL-04 back lens
UWL-04 back lens

The last lens on the market is the Inon UWL-H100 with dome. This lens is available with an M67 mount and with an LD bayonet mount. Due to the size and weight of those lenses in water (100 to 500 grams weight and diameter between 125 and 152 mm) a bayonet mount is my preferred choice.

The Inon lens is actually made entirely of glass, the dome is the biggest at 115mm for the lens with an overall diameter of 132mm. This lens is the more suitable to split over under shot and promises a better contrast and less flare than the other lenses with plastic domes. Inon had some concerns about plastic domes and flare following the performance issue of their UFL165 so went for 100% glass for all next generation lenses.

Vignetting with RX100

In certain conditions all those lenses actually have some vignette in water. Despite what you read on shop websites if you look at real pictures there is a bit of that.

The Fix and Idas lenses have an issue with the lateral hood, the shots look clear of vignette on land but in water the magnification of the hood petals makes them show in the picture, we are talking a minimum crop required around 1% and usually on one side. The Inon UWL-H100 has a different issue and it gives in specific situations a tiny bit of vignette in the corners, around 2% of the image needs to be cropped. Both lenses will not vignette when image stabilization is deactivated, the image stabilizer tends to aggravate the issue so if you are obsessed switch it off and try to be steady shooting at speeds of 1/125th of a second or faster. For example on the amount of vignette see the following

UWL-04 note the vignette left center
UWL-04 note the vignette upper left center
DSC02620Corrected
UWL-28M52R again vignette on the left upper side
SONY DSC
UWL-H100 vignette in left corners

I would like to thank Alex Tattersall, Tamas Plotek and Troy Williams for those in water pictures.

Inon UWL-100 28AD

Inon has another lens that is suitable for the RX100 and is the UWL-100 28AD a lens originally introduced in 2005. This lens has a smaller rear element than the UWL-H100 and it is not suited to many cameras with a very large lens aperture. The RX100 however works fine with this lens and contrary to the newer UWL-H100 this lens does not vignette in water or on land. The reason is that the de-magnification of this lens is less than the newer lens 0.63x vs 0.6x. This is the lens I have chosen for my RX100 Mark II and I will compare it here with the UWL-04 I have recently bought for my Canon S95. There are no substantial differences between the UWL-100 28AD and the UWL-H100 in terms of optical quality.

Here are few pictures to compare the lenses, take into account that whilst the weight on land is comparable, once in water the Inon lens is heavier at 400 grams versus 160 of the UWL-04.

UWL-04 UWL-100
UWL-04 UWL-100
UWL-04 UWL-100 profile
UWL-04 UWL-100 profile

 

Image Quality

There is no need to take the lenses in water to compare image quality generally things get worse in water not better so it is sufficient to take a shot on land and see how that goes to have a relative comparison between two lenses. In this example the cameras are on a table exactly in the same position when the shots are taken and use the same settings of ISO, aperture and shutter speed.

The first impression is that the UWL-04 is a tad wider but more rectilinear, the Inon lens has definitely more barrel distortion and is more a fisheye than the UWL-04 is. Looking at mid upper frame you can see that at diagonal level the UWL-100 28AD is actually wider than the UWL-04 that remains wider horizontally. This means looking at the specs can be misleading and results depend on the camera lens combination.

So how do these lenses compare when it comes to corner sharpness and flare?

This is a shot with the UWL-100 in very harsh conditions with sun-rays hitting the lens directly on the dome, you can clearly see the ghosting that comes from it.

UWL-100 Sunlight
UWL-100 Sunlight

This is the same shot in the same place taken with the UWL-04 you immediate notice that the ghosting has a green color. This is most likely due to lack of anti-reflection coating inside the dome and to the color of the inner lens mount.

UWL-04 Sunlight
UWL-04 Sunlight

Looking at the image the picture taken with the Inon has a clearer ghosting but then is sharp in the rest of the image, the UWL-04 image has flare around it with comparable less contrast as we move from the center to the corners.

The other two images are a crop in the corner, you can see that despite the high level of distortion you can still distinguish some detail of the small grass bush in the Inon image, the UWL-04 instead is softer and the bush is basically a uniform green shape with no detail at all.

UWL-100  Crop
UWL-100 Crop
UWL-04 Crop
UWL-04 Crop

Update 28 Feb I have taken some shots with the UWL-H100 and the UFL165AD here are the overviews

Inon UWl-H100
Inon UWl-H100

The UWL-H100 is actually wider than the UWL-04 with the Sony RX100 despite the advertised 144.5 degrees versus 165 of the UWL-04. Has the same level of detail of the UWL-100 28AD

Inon UFL-165 AD
Inon UFL-165 AD

The UFL165AD flare issue is obvious in this shot both lower corners are compromised, this confirms why the UWL-04 is the best option for the Canon S series in terms of flare or vignette.

Looking at the UWL-H100 crop you can see the vignette more apparent in the upper corner and the image sharpness, it is possible that with an M67 mount there is no vignette with a Nauticam housing in most conditions, with LD mount you need to turn image stabiliser off or crop. Considering this is the widest lens it is not a big issue. Once cropped the UWL-H100 gives still the widest field of view but someone maybe be annoyed by this. Zooming in results in the same field of view of the UWL-10- 28AD

Ergonomics

The Inon lens presents the benefit of a bayonet mount, although the lens is heavy it can be removed in water quite easily, the UWL-04 has some issues whereby the adapter ring would unscrew instead of the lens, this can be avoided fixing the adapter on the lens but then there is no lens cap that would fit the larger M67 screw in the box so you need to buy one yourself, generally the size of the petals make this lens impossible to handle in water and is more like diving with a dome port. It has to be noted though that you can zoom through with both lenses so still continue and take portrait shots and close ups. Obviously for real close or macro you do need to take the lens off which with the UWL-04 you can basically forget.

Cost

The UWL-04 costs $460 in US as shown here with dome cover and step down ring, and £362 in UK. The Inon UWL-100 28AD with dome costs $907.80 including an M67-ADF adapter in US and £775 in UK. All in all the Inon is around near to double the price of the UWL-04. The UWL-H100 is even more expensive at $970 for the M67 version and $942 for the LD bayonet, you then need to add $160 for an adapter for a total of $1,102 that is a lot of money another reason for the 28AD version.

Conclusion

The Inon is the best lens for the RX100 and there is no doubt, however it costs more than double the UWL-04 not everybody will be able to afford it. The UWL-04 is a somewhat basic lens that lacks sophistication and is essentially not removable in water but comes at a great price. In terms of field of view the lenses are very similar with the Inon lenses having more fisheye distortion and a wider diagonal field of view. The UWL-04 is more rectilinear and as consequence has less field of view diagonally. Only one lens has zero vignette at the wide end and this is the UWL-100 28AD with dome.

In Water Shots

I don’t have shots in water yet pending my next trip but two galleries that give an idea are here:

For the Inon UWL-100 28AD with dome look at my Red Sea Gallery https://www.flickr.com/photos/interceptor121/sets/72157645375379256/

For the UWL-04 instead this is an excellent one

http://www.flickr.com/photos/13930495@N06/sets/72157636133030726/

The second shooter has got rid of the UWL-04 to buy an Inon as not happy with corner sharpness!

My perspective is if I look at the pictures I can barely tell the difference however looking close the Inon lens is sharper at one f/stop less, the UWL-04 requires stopping at f/8 or smaller, you can happily shoot f/5.6 with the Inon which means you need less light and less strobe power.