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.
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
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
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.
The peaking function works very well and it is really a strong feature of this camera, it is also very usable underwater
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.
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.
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.
The RX100 has also some key weaknesses that limit its own performance and can’t be cured by workarounds.
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.
Stabilizer 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!!!