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.

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My Sony RX100 Mark II Photo Rig Analysis

So the time has come to talk about photography more in depth. I have actually given up stills in favor of video since a few years as I find video gets me closer to behaviors than stills do, I guess am just not patient enough to capture behaviors on still as that involves waiting!

Anyway this is the rig as it is today without the floats.

Sony RX100 Mark II Still Rig as of 2014 January 20th
Sony RX100 Mark II Still Rig as of 2014 January 20th

The RX100 is a demanding compact for the very same reason why it is the best compact the huge sensor it sports. If you come from shooting a canon or panasonic or even Olympus on a 1/1.7″ sensor you find the RX100 to be very unforgiving. In essence you can’t really just point and shoot you need to put some more thinking into your shots.

The rig that I have put together for stills has the same meticulous attention to detail than my video rig has, you would say OCD probably but here it is.

So let’s start with the housing, Nauticam just makes the best most ergonomic housing for the RX100 period. There is nothing you can think of improving about this housing. Even if the bulkhead connector is useless you can actually put a vacuum valve on it to put it to full use.

Nauticam do offer an M67 thread native on all their compact housings but I find this tedious to say the least. The beauty of a compact is that you can shoot wide and macro on the same dive, the M67 thread in essence negates this as it makes virtually impossible to change lenses on a dive. This is the reason why I went for the Inon 28AD mount for my rig using an inexpensive 10 bar adapter priced at $20 or £15.

M67-ADF adapter with Inon UWL-100 attached
M67-ADF adapter with Inon UWL-100 attached

Once you connect the Inon UWL-100 28AD the lens is very close to the housing to the point of nearly touching the port. This means you get no vignette with this lens with the added dome, and actually a larger field of view in water than you get with the UWL-H100. Why is that? The UWL-100 28AD has less magnification so it does not vignette even on land, once you add the dome you get almost the same field of view in water around 150º. The lens is just a tad lighter than the UWL-H100 with an in water weight of 400 grams.

The choice of the 28AD mount means you can only use the UCL-165AD close up lenses, that if attached would crash into the glass, you need therefore a 28AD->AD adapter from Inon.

28AD to AD adapter with UCL-165AD attached
28AD to AD adapter with UCL-165AD attached

You do get vignette until 50mm however this is not an issue as you shoot those lenses at the tele-end.

This is the whole lens set with the two adapters.

Two UCL-165AD, UWL-100 28AD with dome, 28AD->ADF adapter, M67-28ADF adapter
Two UCL-165AD, UWL-100 28AD with dome, 28AD->ADF adapter, M67-28ADF adapter

As discussed in other posts the two stacked diopters give you super macro, they are also light with 35 grams each in water. The small amount of fringing they give can be eliminated in lightroom with a single click.

Inon UCL-165AD x2 with Inon 28AD to AD adapter
Inon UCL-165AD x2 with Inon 28AD to AD adapter

The wide angle lens sports a 115mm optical glass dome with inner anti-reflection coating. If you are into observing fine detail you will notice that the dome is not actually a full semicircle but flatter, if you add the special coating this means no flare and increased contrast. If you wonder why shots taken with Inon dome lenses are sharper is because only 1% of the incoming light is reflected, against 3% of an acrylic dome, the glass dome due to the coating don’t flare, plastic ones do as simple as that.

Inon UWL-100 28AD with Dome
Inon UWL-100 28AD with Dome

Now let’s move on to the strobes a twin Inon Z240 set. I have been a sea and sea user for years until I managed to damage my YS-01 and got no assistance at all from S&S since then I decided to go elsewhere.

What I love about the Z240 is the variety of controls to manage shadows, the sharp aiming light with a red filter good for the most skittish critters. Contrary to what many people think I aim directly at the subject in macro as the distance is short and backscatter is not an issue so no point aiming the strobes away for me.

FIT Sea and Sea adapter for Inon Strobes
FIT Sea and Sea adapter for Inon Strobes

I happened to have a pair of Sea and Sea optical L cable that served me well and had no will to change, FIT produces this cost effective adapter that goes on your Z240 and makes it compatible, I just love it.

Inon Z MV Strobe adapter
Inon Z MV Strobe adapter

I believe Inon Z MV strobe head adapter has no equal in ergonomics but for some reason a part that is $20 in Japan sells at over $40 in US and £30 in UK so is not that popular. My second choice would be the Nauticam strobe adapter that has got the small feet needed to correctly lock on the strobe head.

Sola 1200 on Loc line mount
Sola 1200 on Loc line mount

With the Z240 doing wonders as aiming light there is no real room for a focus light however I have a set of Sola Video 1200 and what I like is that you can use them as dive light. I have connected them with a locline cold shoe, this will soon change to a ball mount, as the cold shoe is on the left side. Probably I will get a Sola Dive 800 so I can leave my two trays set for video and stills on the boat.

Left Handle Ultralight TR-DHB
Left Handle Ultralight TR-DHB

Looking at the tray I use ultralight, it simple and sturdy and allows me to center the port in the middle of the tray.

The most attentive will see that the two handles have different colors.

Right Handle Ultralight AC-H
Right Handle Ultralight AC-H

Why is that? Firstly I want to place the handles at maximum distance, second by placing two different handle I can ensure the ball is at the same height, this would not be true if I was using the same handle on both sides. I use a TR-DM with a TR-DUPL long extension to make the tray 30cm or 12″.

Sony RX100 Mark II Still Rig as of 2014 January 20th
Sony RX100 Mark II Still Rig as of 2014 January 20th

So this is what it looks like, there will be floats on it, I estimate I need 8 floats to make the rig neutral with the lenses off. I am planning to place 3 on each 8″ arm segment and two on the tray however I might change this to 2 on each arm and a bespoke float on the tray bottom. I will run some test to see what works best.

So that’s all folks surely there will be questions and I look forward to answer them.

Just want to remind you that if you are in the market for a compact still or video rig I provide a personal shopper service for £30 or $45 that provides an end to end service on your budget where all you have to do is to call the shop to pay. Of course we would discuss any observations about the set up before this gets finalized, but am sure better to spend a little amount instead of making expensive mistakes!

UPDATE 9 June 2014 I have made some more changes to the rig the current version (never say final) is here

Photo Rig Current

Sony RX100 Mark II Bulkhead Connection Flop

In this post I will investigate for your enjoyment the bulkhead connector available for the Sony RX100 Mark II and will see why this is unfortunately an accessory that is not worth buying. There are other ways to put the M16 port to use for example with a leak detection system but if were thinking of firing strobes using electrical sync cords then think again.

I was today at the London International Dive Show where I met Dr Alex Tattersall of Nauticam UK that also introduced me to Catherine Lai, daughter of Edward CEO and founder of Nauticam and herself operations director.

I felt a bit sorry when I had to explain why the bulkhead was not a workable solution and if you have a look at the youtube video you will understand why, this has been shot by my fiance’ on an iPhone so apologies for the portrait format and occasional shake.

Right so if you didn’t manage to hear the audio or understand the subtitles here is the plain text explanation.

The bulkhead has a single X pin that connects to the center of the RX100 multi-shoe, now this is the same interface that is on the newer Nex and on the A7. The Sony multi-shoe has a complex 21 pin interface that used with compatible accessories can trigger an external TTL flash.

In order for an external device to be recognized the interface of the connector need to connect to the 21 pin slot not just to the center. Nauticam bulkhead adapter is not so complex and only connect only on the center pin.

So the result is that the external connection is not recognized and if you leave the flash set to fill flash, as you would do with an optical connection, the internal RX100 flash pops out and fires away negating the benefit of the electrical connection.

So in order to make it work you need to set the internal flash to OFF. As the pin on the multi-shoe is always live this works perfectly so when you press the shutter the nikonos interface triggers the external strobe which is what should happen.

The little but significant inconvenient is that if you set the flash to off the LCD goes pretty much black as the RX100 has live view on the LCD and only lights up when you half press the shutter. This means is practically impossible to compose any shot unless you have a really bright focus light or there is sufficient ambient light. In any case for a close focus wide angle shot that you will take with this camera with apertures between f/8 and f/11 the screen will look pitch black as in the video even if you set the LCD to sunny weather.

Whilst the A7 and Nex have an option to disable live view in the LCD, the RX100 does not have such option so you are pretty much done and this accessory is not worth buying as it also introduces an additional point of failure for the housing and one for each strobe.

So the supposed big advantage of the Mark II goes out of the window, time to despair? Not at all!!!

As previously anticipated in my first impression post https://interceptor121.wordpress.com/2013/07/27/sony-rx100m2-first-impressions/

I had the impression that the internal flash was recycling much faster than the original RX100, well I have done some tests and I can confirm what imaging-resource has measured: the flash recycling time at full power goes from 7.2 sec of the RX100 down to 4.4 seconds of the Mark II.

Now this is significant because after your shot you need anyway 2 seconds to recharge the strobes and look at the image preview after the shot and probably another 2 seconds to recompose the shot, at that time the RX100 Mark II will be ready to shoot again at full power.

The improved CIPA rating of the Mark II also means well in excess of 200 shots at full flash before having to change the battery so there is no big deal that the electrical option is not workable, get yourself a twin set of Inon Z240 (my current favourite) or Sea and Sea YS-D1 and you will have no issues compared to any other compact as the RX100 Mark II has the highest CIPA rating of all compacts on the market that are good underwater.

In fact the most significant improvement of the RX100 Mark II in addition to the better performance in low light is certainly the strobe recycle time, from 7.2 to 4.4 is nearly a 40% improvement and the Mark II is faster to recycle than a Canon S120 although not as fast as the G15 or as fast as the Panasonic LX7 or Olympus XZ2. However we are talking about 1.2 seconds difference I doubt that is such a big deal

Clearly the RX100 Mark II is the best compact camera for both still and videos and I look forward to shooting more stills with it.