Sony RX100 – Tips for UW Video Part 6 – Housing Choices

I have a been a bit busy lately fighting with the MTS video files that the RX100 produces, I finally have an automated tool that converts all files into MP4 ready for iMovie that works a breeze.

Anyway this post is not about that workflow but about housing choices. I have received quite a few inquiries about housing choices and although I am not associated with any manufacturer or reseller I thought it would be a good idea to share my thinking.

When I had to choose a housing for the Canon S95 I chose a Recsea, in fact my buddy uses it, the latest WHC-S95D for still pictures and it looks pretty much like this.

A few bits got me frustrated with the Recsea housing one was the rear control.

This may look great but I have been frustrated when underwater the pressing of the buttons was mistaken for rotating the dial itself.

The other thing that I thought was pretty poor was the cold shoe for the focus light, this is a small piece of metal and the screws need to be treated with thread lock if you don’t want to lose it underwater.

Not to mention the mode dial that is really stiff.

Finally the bottom of the housing where the screws go is made of steel threads, in fact you should be careful not to leave an aluminum tray in salt water as it might corrode the housing. This may seem unlikely but I have seen other Recsea housing with huge speckles that mean corrosion.

Recsea produced a housing for the Canon S100 that introduced a front ring like the one on the camera itself but the housing remains the same of the S95 for the other features.

The choice of the Recsea housing over others at the time was mainly because it was easier and more cost-effective to get adapters for the Inon AD lenses I have.

So when the new  housing for the RX100 came out, first on the market from Recsea, I studied carefully the pictures to see how specific issues had been addressed. In essence the  housing for the RX100 is the same of the Canon S100 and has the same annoyances that I did not like with the S95.

So I waited until Nauticam came out with their product, which is in fact made by the same plant that did the Fisheye-fix for the S90/95/100 we can recognize the same features in this housing.

The first is that there is no integrated rear dial,  the buttons are separated from the rotation, this means the housing is very precise and there is never confusion in button presses and response from the camera.

The second is the top of the housing itself, the mode dial is smooth and the cold shoe is top quality as it was the fix s100.

The cold shoe is robust and takes easily not only adapters for 1/2″ loc-line but also 3/4″ which is great.

Finally as it was on the fix housing the bottom of the housing has got two zinc plates to act as cathodes and avoid corrosion.

There are other two incredible plus points of the Nauticam housing:

  • the moisture alarm, I don’t recall seeing one for a compact but the Nauticam has got it and it works as well
  • The housing has an M67 thread that allows you to mount lenses without adapters

Personally I don’t like M67 wide angle options for the RX100 as those are heavy lenses in water however if you already have them than you are sorted.

What about the Ikelite housing? Ikelite had issues of sticky buttons with the Canon S100 so for the Rx100 they have gone back to a large form factor. Personally I don’t believe a polycarbonate housing of such size is very appealing however if money is lacking this is the only choice at the bottom. It does not come anywhere near the quality and features of Nauticam or Recsea.

There is also another housing from Patima that has just been released, I have just seen the pictures and  it does not look particularly attractive, the closing latch looks ancient,  the rear section has button and dials too close and the control ring control placed on top of the camera is just unpractical. It is priced at source at $699 so 27% cheaper than the Nauticam, but this comes at a price: there are plenty of design shortcuts that may create usage issues underwater.

In conclusion the Nauticam I believe offers the best quality and value for money for the RX100, with the exception of the front ring being operated in a traditional mode I don’t see any faults with this set up and I would recommend it for both video and stills, if you don’t have that amount of money and you want to use your RX100 just for video then the Ikelite is worth a try, but not if you want to use the camera also for stills. Nothing specific to Ikelite but transparent housing give too many issues with strobes to even bother.

Sony RX100 – Tips for UW Video Part 5 – Video Modes

Yesterday I had the opportunity to take the rig in the pool and try the steadyshot in water. Clearly it is not really accurate to compare like I have done but it gives an idea you can check it out

This made me think about the video modes implemented in the RX100, as we know there are 4 surprisingly for a compact:

  1. Program
  2. Aperture Priority
  3. Shutter Speed Priority
  4. Manual

The manual option may sound very exciting to someone that comes from still photography but in the end is not that significant in video. Not sure how many have heard about the ‘180 degrees shutter rule’ anyway google it there is some good explanation there. In essence once you fix the frame rate you have pretty much fixed the shutter speed as well so this takes away one of the exposure variables, we are left with aperture and ISO.

Aperture is available in 1/3 of Ev however in wide angle shots with a wet lens most of the times with subjects 10 feet or 3 meters away the camera even with this size sensor has so much depth of field that there is no much point bothering.

ISO in video goes from 125 to the max in 1 f-stop increments so after 200 you have 400, 800 and higher values that are not good for video as the H264 compression makes the footage grainy. I would recommend limiting the max auto iso to 800 or maybe 1600.

So the manual mode allows you to set the exposure, now is that a good thing? As seen earlier on Part 2 this is indeed a good thing in specific situations such as wreck penetration, caves and the likes. It is not however that great for general wide angle and if you ever happen to do camera pan or change the angle of the camera. Panning is not that great in underwater video but sometimes you need it and fixing the exposure is not a good idea.

So the Manual mode is good to take control of the camera in specific situation but in most cases is an overkill as there are not many parameters you can really change independently.

Following on from the shutter speed 180 rule the shutter priority is also pretty useless as we should set the shutter value to a multiple of the frame rate to avoid stuttering.

Aperture priority is instead a great value add of the RX100. Diligently the camera will try and respect the 180 degree shutter rule but in specific cases, for example when doing macro with diopters or in close up, we want to really make sure we have the depth of field required. In that scenario I recommend leaving the ISO on Auto and not set it manually.

So why Auto ISO? Because changing ISO in a digital camera is done amplifying the signal, is not changing film, so in effect the ISO does not need to go in f-stop values at all. So leaving it on ISO the camera might as well apply values that you cannot choose manual.
This uneventful picture taken with the RX100 and an Inon UWL105AD shows a value of 320 in ISO as it has been shot in program mode.

We could not select this value if we were setting the ISO manually but would have needed to choose between 200 or 400.

Aperture priority is my favorite mode for those special situation where extra control is needed.

So what about the Program Mode? Actually that is not bad at all, especially for wide angle shots, as mentioned the shutter speed is pretty much set, in program the camera tries to keep the lowest ISO as possible and opens the aperture accordingly. This behavior may be acceptable with sufficient ambient light so I would not discount this mode at all.

Not bad for program mode with no lights…

A final note the camera uses a shutter speed of double the frame rate in Active Steadyshot and the same as frame rate in standard mode, also for this reason I do not recommend the standard steadyshot even if Active crops the picture in the 1080p50 mode

Sony RX100 – Tips for UW Video Part 4 – SteadyShot Modes

In this post we will look more closely to the image stabilizer options built into our RX100.

The RX100 is equipped with the Sony Steadyshot technology that has been around for quite a while however in this new camera we have a new additional feature that may as well worth exploring for our purposes, the Steadyshot active mode that was first introduced in the alpha series.

The active mode is only available for movies; for stills the choice is limited to the Standard mode, it is of course possible to switch off any type of stabilization, I do not recommend doing this for movies.

So how does the Steadyshot system work?

The standard mode is based on a gyroscope sensor present inside the camera that gives information to the microprocessor so that this can adjusts the relative position of the camera sensor with respect to the lens and compensate for the movement of the camera. More details are on the Sony website here.

There is no doubt that optical stabilization is a great help for still pictures however we have all experienced that this does not really lend a great help in situations where the camera moves quite a bit, for example if you walk with it taking footage, or in a dive when you have surge or uneasy conditions.

Usually in post processing we then add a software stabilizer that works out the camera’s pan and rebuilds the frame around it, this  comes at the expense of cropping.

Some cameras do not have an optical stabilizer but only an electronic system which is equivalent to the routines that editing program implement in post processing, Sony with the SteadyShot Active mode combines optical and software stabilization techniques.

I have put the RX1oo on an tripod fronting the window frame and set the camera in SteadyShot Standard mode, the diagonal field of view in this case is 73.44 degrees (it is actually 72.97 if we calculate accurately but let’s not worry for now).

You may wonder why this is not in excess of 75 degrees as the camera has a 28mm focal length at 35mm equivalent, this is because the camera sensor is 1″ wide with a 3:2 form factor, but in movie mode we are in 16:9 so part of the picture is lost and this makes the field of view smaller. In fact Sony declares the 35mm equivalent as 29mm in Movie mode, against a more accurate calculation of 29.25mm.

In this shot we see the camera in the same position but now in SteadyShot Active mode.

We see that we don’t have anymore any light on the sides of the window frame in fact right now this completely fills the camera frame.

Sony declares an equivalent 35mm focal length of 33mm in active mode that reduces the diagonal field of view to 66.5 degrees this corresponds approximately to a 10% reduction at field of view level. This crop is needed by the camera software in order to work out the camera pans and have sufficient margin of error for the calculations.

Now when it comes to underwater video should we be tempted by the SteadyShot active mode even if that means loosing some field of view? I guess it depends, most of compact camera users do not have underwater tripods, and the additional stabilization help is welcome especially when zooming in for example for macro or performing panning shots.

In this video you can compare the two steadyshot modes

This also brings another consideration in mind, there are many wide angle lenses designed for cameras with 35mm equivalent focal lengths, that could be suitable if we intend to keep the Steadyshot in Active mode.

A lens that immediately springs to mind is the Inon UWL-100, this is a lens with an M67 thread as natively supported by three of the housings currently available for the RX100, the Ikelite, the Nauticam and the Patima, an M67 mount adapter is also available for the Recsea housing.

The Inon UWL100 supports camera with focal lenght >31.5mm and would on paper be suited for video use with the RX100 with steady shot in active mode, this lens should not vignette at the widest setting due to the image crop and reduced field of view of the 16:9 frame in movie mode.

Another lens that come to mind similar to the Inon is the Epoque DCL-20 or Ikelite W20 those correspond to the Inon UWL-100 with mount type 2 and might not be suitable for the Ikelite housing. Ikelite tends to position the thread further away from the port so I invite you to test yourself before drawing conclusions as the increased distance lens to port generates soft corners.

Finally the Olympus PTWC-01 is also a potential candidate for testing for what concerns the M67 options.

If you happen to have any of those lenses with your current set up and are thinking of upgrading to the RX100 to use it for video you may well be able to use your lenses again and save yourself additional investment.

Sony RX100 – Tips for UW Video Part 3 Setting Custom White Balance

In this third post we will look at setting custom white balance in our RX100.

The ability to change the color temperature and adjust it to the conditions is essential to take underwater video as the ability to correct white balance in post processing is nowhere near what you can achieve with RAW files in photography.

Unfortunately the RX100 does not allow to set a custom white balance in video mode, and actually does not allow setting it in many other modes either. So to achieve our objective we will need to use the mode dial.

Note that the RX100 has the ability to store custom setting in 3 memory recall modes however in this mode the set custom white balance option is not available.

As we don’t have a one push option we need to minimize key presses to build a reliable routine that we can recall underwater.

If we have a look at the mode dial we see that the Manual mode for stills M is the closest to the video position so our routine will be based on switching between M and Movie mode. Update The new recommendation is to set the dial to P see note at bottom

Preparation is important and the RX100 has two options when it comes to recalling functions from the menu as we can see from this picture.

It is essential for our purposes that in this screen we select Previous, this will position us on the last entry we used when we click on the menu button again. The other option Top does not recall what the last entry was and puts you back on the top of the relevant menu, and would mean more navigation for us, so make sure you are set on Previous.

Another important trick to remember is that through the Function button we can recall the various white balance settings. In my set up white balance is right in the center of the function option so that when the function button is pressed we are immediately there should we need to change it back to Auto when we use lights, so when we plan to custom white balance this should be left on the Custom position as in the main picture of this post.

The other preparation that we need to do is to go in Manual Program mode and navigate until we reach the entry that allows us to set custom white balance as shown in the picture.

Note that from here we still have to actually select and go into another menu to then finally navigate to the bottom where the set custom wb option is.

We now want to re-balance either on slate or some grey area or sand so how do we do it?

The starting point will be in Movie mode with the White Balance set to Custom (remember this is not to set a new WB but just to recall the last white point set).

This is the step by step routine:

  1. Move the dial to position P
  2. Press Menu – this will position us on the white balance entry in the menu
  3. Press Enter (central button) to access the options
  4. Scroll to Set Custom
  5. Press Enter
  6. Point at the slate and press the shutter
  7. Press Enter
  8. Turn mode dial to Movie – as we were set in function to Custom White point recall the setting we capture will be used

And we are done an 8 steps routine!

If you were used to a one push option this is a shocker!!!

For those on the more conventional option Menu-White Balance-Custom WB-Set-Menu this adds 3 more clicks.
Sony had made two very poor design decision for our underwater video purposes

  1. It has negated the option set custom white balance in video and now two turns of the Mode dial are necessary
  2. It has allowed to set a custom white balance only from the Menu but not from the White balance options that you can recall with the Function button, additional navigation is required because of this

I believe those issues can be fixed by a firmware update quite easily as they are clearly software issues the camera itself has got all the required capability.

That’s all for now if anybody has any alternative approaches that improve this routine I look forward to hearing what those are!

Meanwhile I recommend sending an email to Sony Support to ask for firmware changes…

Update 14 December 2012

Many people report a Custom WB error 9900K message. It turns out the RX100 fails to set custom white balance set up if the exposure is not within -2 to +2 range. So the new advice is to set custom white balance while in P mode

Sony RX100 – Tips for UW Video Part 2 – Rear Dial Buttons

In this second post we will look at how to set the rear dial buttons to best suit underwater video.

The RX100 has got a whole load of settings and not the most user friendly menu structure so it is important to have the features you need at your fingertips when the moment comes.

There are 3 essential features that a camera needs to have for underwater video:

  1. AF lock
  2. Exposure Lock
  3. Set custom white balance

Unfortunately as Backscatter noted in their review of the RX100 there is no possibility to set a custom white balance in any of the video modes, however in the next post I will guide you through the best available workaround that minimizes the chances of you getting completely lost in the menus…

It may be beneficial to understand first why those features are important so let’s have a look one by one.

AF Lock

Have you ever experienced being in a school of fish? Or looking at some frantic behavior in front of you or simply seeing glassfish swarming in front of your camera lens?

It will look something like this…

This is not a still picture but a snapshot of a clip taken at 1/125 sec shutter speed, the action was actually fairly fast.

This is the clip if you want to check it out,

this scene is in the first part of the movie and  has been shot with AF Lock on a Sanyo Xacti HD2000.

What would have happened without AF Lock? The camera would have been looking for focus and mistaking some of the fish coming close with the actual subject and as result the clip would have been unwatchable. So this makes focus lock very important for us in all situation where we operate in tripod mode with moving fish in front of the lens.

The RX100 does not offer AF Lock with a single push, and in video mode the choice is between tracking auto focus and manual focus. To emulate the AF Lock feature I follow this procedure:

  1. Track my focus point with tracking AF
  2. Switch to Manual Focus

Note that is not possible to simply cancel tracking AF to obtain AF lock as the contrast detection system will still wonder around the center of the frame.

This means that one of the rear dial buttons accessible in the menu settings 2 should be set to AF/MF Control Toggle that will allow us to quickly operate the steps above and move with one click from tracking AF into manual and effective locked focus.

Exposure Compensation

Another essential feature of video as we don’t want the camera to continuously adapt to the changing light conditions of the scene. To give an example let’s have a look at this picture:

This is a swim-through that is a common features of little caves or even wrecks. We don’t want the camera to compensate for the lack of light whilst we go through as that would increase the ISO and make the footage grainy, also the scene would get brighter and not reflect to the viewer the same experience we had.

Exposure lock avoids this situation so when we are at the beginning of the cave we lock exposure and the scene stays dark so that the end of the swim through gives a beautiful effect. Another example with this technique

So we should reserve another of the rear dial buttons to Exposure lock that on the menu system is called AEL Toggle

This is how my rear dial configuration looks in the Setting menu 2

Note that I left the center button to standard as that corresponds to tracking focus. That is required for the pseudo AF lock in conjunction with the Right button as discussed earlier in this post.

Sony RX100 – Tips for UW Video Part 1- File Formats

When the new SONY DSC-RX100 was released early June many people were really excited as this camera featured a 1″ sensor at its heart.

Scott at Underwater Photography guide posted a raving review from which I was left salivating

Later on backscatter selected the RX100 as the best advanced camera of the year read more here however one statement left me concerned in the Pro and Cons section: No way to execute custom white balance in movie mode, must jump to photo mode

This sounded quite uneventful considering that we are almost used to one push custom white balance on most mid level compacts.

Maybe those guys looked at the Sony entirely from a still perspective and did not make much of the features or lack of thereof that this Sony has, anyway I have now bought the camera itself and I am facing a few issues and dilemmas.

Let’s take a close look at those one by one and start this issue with…


SONY has decided to adopt the new high specs AVCHD formats for this camera, I will from now on refer to 50p or 50i to indicate 50 progressive or 50 interlaced frames as this is the PAL standard. This would be 60p or 60i for NTSC US and Japanese users.

The AVCHD format had initially a 1080/50i and a 1080/24p format and a bunch of lower resolution formats, later on a 1080/50p format has been added with an increased bit-rate of 28 Mbps instead of the original 24.

Now you would normally assume that Sony would have chosen to support all those formats and instead has decided just for the 1080/50i and 1080/50p. The universal 1080/24p format that is compatible with both PAL and NTSC is not supported on the RX100. Why has Sony made this decision is a mystery.

The make things worse today interlaced display do not exist anymore and most of the non linear video editor convert interlaced footage in progressive otherwise you can’t actually edit the clips. Not only that very few software programs actually accept the new 1080/50p format, with the notable exception of Sony software that even at low level supports those formats. Adobe premier is another one, but the whole set of Apple software including iMovie and Final Cut Pro don’t know what to do with those files. Let alone the fact that no devices except powerful computers can actually play those files well.

The RX100 offers an MP4 format at 1440×1080 rectangular pixels with a 16:9 aspect ratio as a reminiscence of HDV. This format is however easily digestible by the majority of NLE on the market. So we would feel rather tempted to use it.

The question is how do we set our RX100 to capture underwater video?

The answer is actually at the highest possible setting that is 1080/50p. There are several reasons for this.

  1. The human eye is very sensitive to resolution. So the MP4 1440×1080 format goes out of the window
  2. We can still change the frame rate in editing phase to make the file a more normal 1080/25p
  3. There is not a huge difference in memory card use between the 24 Mbps of the highest interlaced mode and the 1080/50p
  4. It is easier to edit progressive frames without conversion
  5. Progressive footage does not introduce artifacts as  interlaced does

On a negative note the fact that we are saving AVCHD streams means goodbye back ups on our tablets or mobiles so plenty of memory cards with us during our trips.

The next challenge will be to import the AVCHD streams into our movie editor. As mentioned earlier the 1080/50p format is not recognized by many entry level programs so some will not even see those files.

Other programs will try and convert it, this option has to be disabled and the files imported as they are without any changes to preserve quality.

So what do we do if our software refuses to process the 1080/50p files in our AVCHD streams?

A number of help tools come handy unfortunately the freeware one are mostly on windows and I have not managed to produce anything that works yet with Wine for Mac. On Mac there are two tools iVI that costs $9.99 and ClipWrap more expensive both functional and will produce an M4V or MOV that can be processed with iMovie or other tools that would have previously rejected the file you go figure!!!

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