Sony RX100 – Summary of Underwater Video Performance

Few months ago this clip came out

Many people including me got really excited about this camera and had a go at underwater video with it

Now it is time for an end of year review and summary of my experience with the Sony RX100.

Without a doubt the camera is a game changer and there are some feature that are especially suited to underwater video.

Key Strengths

Bright Lens

The RX100 does very well in low light this is a strong selling point for underwater video, even in cloudy days the camera does extremely well

Low Noise

The camera performs very well in video mode up to ISO 800, the level of background noise is really low and the footage clearly benefits from it

Image Quality

The quality of video if we focus on the center, as well at the telephoto end is impressive. Color rendering is very accurate and there is even the option of using Adobe RGB. The dynamic range of the camera is excellent and the image is vibrant.

Video Mode Control

There is full manual control in Video mode and the option for aperture and shutter priority. The program mode does very well. Only an Auto ISO option in manual is missing but this is negligible. Indeed the most interesting mode is aperture priority.

Manual Focus

The peaking function works very well and it is really a strong feature of this camera, it is also very usable underwater

Battery Life

You can easily do 3 dives with the RX100 without having to open the case which is great and actually unusual these days when even a gopro does not last one hour.

Active Steadyshot

I initially slagged the RX100 stabilization system based on performance on land. However at a more in depth analysis it turns out that the RX100 active steadyshot, even if at cost of an image crop is very effective for sudden camera movement and for high magnification macro. The Stabilizer is not as sticky as others so when you eventually vibrate it does not jump. Although the performance for stills is poor to irrelevant and so is the normal mode the active mode is very effective for underwater use.

Tedious Workarounds

Some of the ergonomics of the RX100 are not the best and seriously deduct from an otherwise excellent experience, the most annoying issues:

Lack of focus lock

For some reason Sony decided to skip on this essential feature, the workaround involves switching to manual focus using the function dial however it is then possible to accidentally change focus.

Setting Custom White Balance in Video

Setting custom white balance is only possible in the still modes, while in fact if you shoot RAW don’t actually need white balancing. This is the largest non sense of this camera that requires the user to navigate out into Program to ensure white balance is set correctly and you don’t end up with the Custom WB Error message. Really an awful issue that Sony should try to fix in a firmware update

Lack of 24/25/30 progressive modes at 1080HD

Sony thought that for some reason you either shoot interlaced or you go directly at double frame rate with a 25 or 30 progressive mode only available at reduced bit rate and resolution of 1440×1080 with rectangular pixels. Why did they do that is a total mystery. You are therefore forced to shoot at the highest mode of 1080p50 or 1080p60 that produces large files difficult to digest by many programs. Sony decided to keep a bunch of interlaced modes despite the fact that there are no programs that can edit those without conversion and that CRT Tvs don’t exist since a little while.


Sony embraced AVCHD maybe because their software handles it well but what about the rest of the world? Mp4 is the standard for video clips on the internet and AVCHD adds absolutely no feature to it for simple video recording. Files have to be systematically converted, sometimes with commercial software, to be used with mainstream non linear editors, not only most would not recognize the files at double frame rate.

Key Weaknesses

The RX100 has also some key weaknesses that limit its own performance and can’t be cured by workarounds.

Macro Performance

The camera does an awful job at close range and needs a diopter even to shoot basic macro. To shoot super macro you need +12 diopters and this requires high quality lenses to avoid chromatic aberrations in the image. The focus mechanism with diopter is a bit of a mystery to work out at times. Once you manage to focus the image quality is great. However the need for a +5 diopter as a starter makes this set up expensive and cumbersome to handle in water compared to others.


Sony has adopted a lens shift approach in this camera instead of the sensor shift of the higher end alpha, maybe due to large size of the sensor compared to the camera body. They have then added some software processing in camera but the results are just average. There are many other cameras that do better than the RX100.

Soft Corners at Wide End

I was going crazy looking at pictures taken with different wet wide-angle lens to check which lens was best, at the end of hours of observation I took some shots on lend at the wide end. The issue is not with the wet lenses is with the camera itself, it has very soft corners until at least f/5.6 and not the sharpest corners anyway afterwards. This cannot be cured and is a key weakness that is not so apparent in stills where you can crop quite a lot 20 megapixels but obvious in video.

No Neutral Density Filter

The RX100 has a bright lens and low noise however in video the ISO starts at 125, in many situation near the surface the camera maxes out at f/11 and then starts increasing shutter speeds to 200 400 800 and so on producing scatty mechanical images. Neutral density filters have been implemented for ages in cheaper camera and take away 2-3 f-stops allowing the camera to operate at wide aperture. For some reason Sony decided not to do anything about this. On land this is an even stronger limitation in bright days.

A final remark that I want to include for all those that use the RX100 for still photography that indeed is the real strength of this camera.

Another key weakness is the strobe recycle time not an issue in video of course but creating several issues of missed shots for photographer

In conclusion the RX100 can produce great footage but has some limitation that need to be taken into account.

If you go muck diving on flat surfaces with a couple of diopters and good video lights it is of course all looking wonderful but the situation changes when you cannot lay down as in my seahorses video

With two Inon UCL165AD stacked it is really hard to get some decent footage and due to the large sensor the depth of field at such level of magnification is pretty much zero.

But the limits show up more in the wide angle where the soft corners come up no matter what you do as very seldom you are able to shoot at f/5.6 or higher at depth below 12 meters or 40 feet

Whoever wants to try the RX100 for video please get in touch if you have more questions and happy 2013!!!

10 thoughts on “Sony RX100 – Summary of Underwater Video Performance”

  1. Hi Interceptor

    First I would like to thank you for your excellent work related the RX100. It is extremely helpfull.

    I just reveived my Rx100 a few days ago and I am under certain doubts if going forward and get a housing for it.

    The reason is that what I have seen in your videos is bellow my expectation from this camara in comparation with what I already have ( an old Panasonic TZ7).

    I just recorded this video in the Maldives (( , there are obvious differences , mainly in the close ups but when we talk about wide angle then is when I am not seen the sharps views I would expect from the Sony.

    Still I have time to take back my Rx100 and get a Panasonic TZ30 ….instead of jumping to the RX100 case.

    Perhaps is that the youtube video does not show the same quality than having the file or that the visibility in Raya Ampat was poor…..

    What do you think?

    Also If you don´t mind I would aprecciate if you suggest me what Wide Angle and Macro I should go for.

    In Macro I do not have much experience.

    Related to the case from your comments I know you will advise the Nauticam.

    Still I am going in circles if I should go for the Nauticam or get the Ikelite..

    But everytime I think about the currents I got in the Maldives and having to use two hands to zoom (Ikelite) I bend to the Nauticam.

    Thanks in Advance
    Kind Regards

    1. Hi Xabier
      You posted an incorrect link I guess you meant this?

      I have been to the Maldives a few times and the visibility is great, in Raja Ampat unfortunately we had around 8-15 meters on average and the water was full of nutrients that made it good for fish but not so good for actually seeing the fish themselves
      Maybe this video gives you a better idea as it was shot on a dive site where the viz was better

      For what concerns your comments about the sharpness of course Raja was not the best for the camera it was the first time I was using it in the ocean and I had many issues with the specific problems of white balance for example, also because there was little light the camera was shooting mostly at wide aperture so that the image is not that sharp. For me the RX100 is a great camera for photography but maybe not the best for video, if you want to use it for photos and take occasional video then definitely go for it. As a 100% video rig is slightly disappointing considering the cost.
      As housing I would suggest the Nauticam because I don’t like big shoe box style plastic ones, for the lenses there are several considerations around optics quality and easy of use. I like bayonet mounts especially with the RX100 as you need to put on and off the diopter all the time so I use Inon. If you don’t have any lenses and you go for an RX100 I would recommend an Inon UWL-H100 28LD and an UCL-165LD diopter this would do fine for pictures and will be very good for video too. For super macro you need an additional lens on top!
      If instead you want to use the camera only for video stay tuned as I just put my hands on a Panasonic LX7 and a Nauticam housing and I intend to post some information very soon and compare with the RX100 as well
      Let me know if you need more info and what do you want to use your camera for

      1. Hi Intercertor

        I take around 60 % videos.

        Looking forward to hear about your experience with the Lx7 but I do not have much time to change my mind..

        It is a camara I have been thinking about too. But I am not sure if it has so many choices of modifying exposure values once the video is been recorded.

        I like about the Lx7 that there are more HD frames options that just 60p.

        Obviously I also use the camara out of the water and I am happy with it so far.

        Thanks for your advices.

      2. The lx7 has full manual controls in video more modes and a neutral density filter very useful near the surface
        On paper this is the best compact for video on the market
        I will post some generic info in the next post

  2. I’m concerned that the RX100 doesn’t have an underwater (wideangle) mode – I was hoping to take it to photo dolphins, sharks etc… fast moving objects underwater. Now I guess I could play around with the manual settings but in a dynamically changing environment I’m not sure whether that is practical to achieve.

    1. Having an underwater mode has nothing to do with taking the right photos or videos of anything. For pictures you shoot in RAW and for video the AVCHD is more than adequate once you set the custom white balance or alternatively use a filter on your wet lens. The underwater mode is nothing more than a white balance preset with an increased magenta tint so no rocket science

      1. My worry is that trying to set custom white balance won’t be effective in a dynamic environment with constant movement and change of depths – I was shooting (with the Oly XZ1) at Layang Layang in March and we were swimming in depths of 20 – 30 – 40m with Hammerhead sharks and dolphins. I set the custom white balance at 15m but didn’t have time to change the WB as the depth range changed.

      2. The underwater mode that you refer to is not dynamic, It is simply the same as auto white balance with an orange tint. This can be achieved easily on any camera like the RX100 or LX7. Go into white balance setting auto white balance then press right key and move the magenta and yellow sliders to the max. There is no magic in the cameras underwater mode and at depth it will be poor performance. If you don’t want to set custom white balance use a filter, And if you did not have time to set custom white balance because you were changing depth so quickly probably you are risking decompression sickness!

  3. Lol. We were descending downward when we sighted the hammerhead sharks circling at around 30m only a short distance away from the reef surprisingly. We swam to greet them but my settings for WB were set at 15m. In the excitement of having 30+ hammerhead sharks circle around us I didn’t change WB.

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