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4K with the Sony RX100 in Egypt

 

 

It was time to go for a second trip with the RX100 Mark IV

I decided last minute to use the UWL-H100 LD however I managed to forget the M67-LD converter so ended up taking footage holding the wet lens with my left hand.

This created some flare issues in some scenes anyway judge for yourself.

I used the Picture Profile PP6 modified with some small changes around color matrix (I used the Pro setting) and some increased saturation.

As always the RX100 cannot white balance underwater so I used a filter (deeproof), this gives a magenta tinge and sometime the water looked a bit purple.
I have two versions of this clip the first one uncorrected and the second where I tried to remove the purple water. Look for yourself which one is best.

First version with minimal to no editing is here

 

The second version has some colour correction mostly to remove the cast but I have also done some minimal correction in some scenes at the surface shot without filter.

The other settings were shutter speed 1/50 fixed, Auto ISO with max ISO set to 800, auto white balance.

Generally I am very happy with the RX100 however the snorkeling footage was affected by one episode of fogging of the glass port. This was during a dolphin trip so very disappointing. The camera got extremely hot and I think the fact I was holding my hand close to the port to hold the wetlens created the problem as this had never occurred before.

Upon reflection I think I will go back to the UWL-100 M67 type two as the colours I get with the magic filter were superior in my opinion and more natural.

For those wondering about the dugong dugong it was dark as I was free-diving to 12 meters with the camera and the wet lens hand held so not the easiest job.

Let me know which version of the video you prefer!

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What does UHD Premium specification mean to 4K

The UHD alliance is a working group that includes a number of well known brands.

In the board are directors of the following major players:

  • Fox
  • Sony
  • Netflix
  • Panasonic
  • Dolby
  • Technicolor
  • Samsung
  • LG
  • Universal
  • Warner Bros
  • Walt Disney
  • Direct Tv

The members include companies like Sky, Amazon, Intel, Thx, Dts and others.

The key purpose is specifications mostly for high end use and the key pillars are:

  • High dynamic range video (SMPTE ST2084 EOTF)
  • Wide colour gamut (BT.2020)
  • 4K resolution
  •  10 bit colour depth

This is obviously a large improvement compared to the current specification of HD Video:

  • BT.709 colour
  • 1920×1080 Resolution
  • 8 bit colour

Probably the most interesting feature is high dynamic range video as the human eye is more sensitive to contrast than it is to colour and resolution although surely the 10bit colour depth will make a difference.

Currently all professional recorders that manage 4K use 10 bit colour but none uses the BT.2020 colour gamut and the dynamic range is left to the sensor quality and has no minimum specifications.

So what will UHD premium mean to us? Well currently not much!

The key is that UHD alliance has also stayed clear from the major issue for distribution that are the video codecs.

Currently HEVC or H.265 has got royalty challenges but is the most  efficient codec on the market and the widest in terms of diffusion in hardware.

To give an idea two minutes of 100 Mbps H.264 become 76.5 Mbps once you push the H.264 to the limit but the corresponding H.265 is only 13.6 Mbps only 18% of the size.

Google does not support HEVC and are distributing 4K using VP9 and H.264. From my tests VP9 is not as efficient as HEVC the same file came at 17 Mbps. The key issue of VP9 is playback that does not even work on a powerful home computer although some new Android TV have accelerated VP9 and so has the new Nvidia box.

Whilst this gets worked out it is likely that cameras will continue to record in H.264 and the key here is higher bitrate as H.264 is clearly inefficient with 4K.

If you are in the 4K space and you want to produce semipro or pro footage you need to have an external recorder working in Prores HQ or your device needs to be able to record higher than 100 Mbps.

Sony has just introduced the XQD memory cards that write 800 Mbps

http://pro.sony.com/bbsc/ssr/mkt-recmedia/mkt-recmediaxqd/product-QDM128/

This is potentially a way forward for higher bitrate recording as UHS 3 is limited to 240 Mbps and would only work with compressed footage.

Another thing to consider is that you need a pretty big Tv to notice UHD at the normal viewing distances we tend to watch.

http://s3.carltonbale.com/resolution_chart.html

Carlton Bale was on the scene few years ago when HD came about and the conclusion was you need 55″ or more at 8 feet to ‘see’ HD as your eyes can’t resolve more.

This distance becomes 120″ at 8 feet which is essentially the size of a projector screen.

Essentially UHD seems to be more for computer freaks watching clips very close to the screen that for the average user.

I did several test on my Tv with clips I had produced in 4K downscaled to HD and at my normal viewing distance I could not see any difference what so ever!

Essentially I have determined that 50 Mbps XAVC from the RX100 Mark IV looks actually better than 4K on my Tv.

I guess we will have to wait for HDR to see some real benefits meanwhile the clips from you tube look better simply because they have more information. There is a factor of 6x for UHD compared to HD and this shows a higher quality clip.

I don’t see a large future for UHD in TV broadcast it could die as 3D just did.

 

The painful quest of 4K Video

2015 has probably been the first year where consumer devices have taken the journey to 4K as even iPhones now can record at Ultra High Definition.

However there is still a very long way to get us to the level of standardisation of HD video and the war of the codecs has still to determine a winner.

As of January 2016 if we consider only digital cameras only three manufacturers produce 4K capable devices that can be housed for underwater use and those are Canon, Sony and Panasonic.

Specifically we have two compact cameras with fixed lenses, the Sony RX100 Mark IV and the Panasonic LX100, two micro four thirds the Panasonic GH4 and GX8 and three DSLR the Sony A7IIR and A7IIS and the Canon EOS-1D C that was in fact the first camera to record 4K video in 2013.

From a consumer point of view we are interested in a 4K device that can operate with wet lenses across the focal range and that is under the $5,000 mark including the housing so I will focus on the Micro Four Thirds and fixed lens compacts and exclude immediately the Panasonic LX100 that requires a port system to operate we are now left with 3 devices that today are the real options for 4K underwater video.

4K Digital Cameras for Underwater Use

  1. Panasonic GH4 with Panasonic 14-42mm II Mega OIS
  2. Panasonic GX8 with Panasonic 12-32mm Mega OIS
  3. Sony RX100 Mark IV

I have added the lenses of choice of each camera for convenience.

In 35mm terms the focal lengths offered by the 3 devices are:

Panasonic GH4 with 14-42mm : 35-105mm

Panasonic GX8 with 12-32mm: 31.2-83.2mm

Sony RX100 IV: 28-80mm

Wet lenses

Both Panasonic cameras revert to a traditional 35mm cameras when the 4K crop is applied. The wet lens of choice is therefore the old Inon UWL-100 with M67 thread. This is a lens with a magnification of 0.57077 that with the 14-42mm II Mega OIS and Macro Port 35 or the 12-32mm and Macro Port 29 performs very well without vignetting and offers zoom through the whole focal range. The same lens appears to work fine also with the Sony RX100 Mark IV but is almost border line in terms of vignetting and I will need to conduct further experiments for now we will refer to the Inon UWL-H100

Focal range with Inon UWL-100 / UWL-H100* (Sony)

Panasonic GH4+14-42 : 20-60mm

Panasonic GX8+12-32 : 18-48mm

Sony RX100 Mark IV : 17-48mm

You can see that the GX8 and the RX100 are virtually equivalent and the same holds true for macro with the GX8 and the RX100 offering same working distance and magnification. The GH4 is superior in this area due to the longer focal length after crop of 105mm. For me the most versatile wet lenses for macro remain the Inon UCL-165 despite the various Nauticam and Subsee options because you can cover all the working distances from 16cm to 8cm which is the sweet spot for macro work.

Unfortunately the level of magnification obtainable with the GX8 and RX100 is not great and really small subject will still look tiny in the frame. Obviously the use of the 14-42mm lens on the GX8 resolves all problems except the field of view with wet lens at wide end is now 21mm anyway not a huge issue.

I am still waiting for a proper review of the GX8 but in terms of 4K resolution I have been impressed with the Sony RX100 Mark IV that appears to be sharper than the GH4 and even the A7IIR.

4K formats

In terms of 4K recording all devices on the market use some form of H264 100 Mb/s codec Sony uses what they call XAVC S while Panasonic uses a standard Mp4 compatible wrapper. Sony codecs do not use B frames in their H264 implementation but this does not seem to affect quality that much.

So now that you have your 4K footage what do you do with it?

The first consideration is that all cameras record internally at 8 bit with 4:2:0 subsampling this means that colours are only recorded for 50% of the pixels and then interpolated. The implication is that color grading opporunites are limited and heavy manipulation should be avoided to avoid undesired effects such as banding.

This means custom white balance better with a filter is still very much needed for 4K.

In the Mac camp there are many consumer options for 4K editing including iMovie, Final Cut Pro X, Adobe Premiere Pro and for Windows you also add Sony Vegas, Avid composer and many more

S-logs or V-log are also not meaningful at 8 bits without external recording capabilities as grading will ruin the footage.

Workflow for Consumer Use on Mac

For the average home user on a Mac iMovie offers now decent functionality and imports and edits in native format all the clips produced by our selected cameras. iMovie also exports in Prores 422 which is ideal for storing your master copy after editing.

Unless you edit on a laptop or a machine with poor hardware there is no need to convert the footage in intermediate formats as most of GPU have H264 acceleration so your 4K workflow will look like this:

  1. Import into your 4k editor
  2. cut and edit sequence
  3. Perform minimal corrections to exposure and color
  4. Add some transitions
  5. Add music of voice over
  6. Export to Prores 422 or 422 HQ if available
  7. Compress with 3rd party software or plug in

Compression Headaches

Step 6 is particularly important as none of the above mentioned editors has good native export capabilities so you want to do that with another program. If we take for good what apple says Prores HQ is very rarely fooled by 4K footage at 737 Mb/s for 25p. Consindering that our footage was 4:2:0 to start with this means we need only 75% of that bandwidth or 552 Mb/s. As Prores 422 records at 492 Mb/s which is only 11% less than the required bandwidth so iMovie with the Prores export option is pretty good.

We now have our 492 Mb/s video with most likely an AAC audio what are we going to do with it?

This is where it gets really painful. If you have a 4K Tv you definitely want to watch your footage on it, today UHD Tv support the HEVC codec and more recently also the VP9 codec that google uses in YouTube however both those codecs have limited options for encoding and do not have any hardware acceleration support in your computer that will be used to compress the footage.

To make matters worse if you then share your footage online on YouTube this will be heavily re-compressed. I have done some analysis on some clips that I watch to find that 4K bandwidth is between 17 and 20 Mb/s in H264 and the files are not even encoded with CABAC to ensure they can be played on devices with limited hardware capabilities. In terms of web browser many now supports VP9 however hardware acceleration is lacking so it is likely that you will be watching H264 4K footage at 18 Mb/s when you connect to YouTube on your computer.

It is likely that the mp4 files that you can produce with handbrake or other tools are easily coded at 60-70 Mb/s so YouTube, as it does with HD footage, will introduce significant issues to your 4K videos.

Interestingly the 4K bandwidth is higher in terms of Bits/(Pixel*Frame):

  • 0.090 for 4K
  • 0.076 for 2K
  • 0.055 for HD

This would suggest that 4K videos are less compressed but on the other hand the compression is less efficient. 2K appears an interesting mix that still uses Cabac and 3 reference frames but is really a computer only option.

For who has access to an x264 encoder  this is a suggestion for 4K  encoding that does not kill your computer

Preset slower – modified

cabac=1 / ref=5 / deblock=1:0:0 / analyse=0x3:0x113 / me=umh / subme=9 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=3 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=1 / crf=18.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00

The options that differ are ref=5 otherwise we break the limit of level 5.1 and the decoder may have issues, and crf=18 from 23 to increase quality.

This H264 encoding can easily produce files around 1.4 Gb for just 3 minutes and will require playback on the device or USB disk attached or a good cat 5 ethernet network or solid wireless at at least 100 Mb/s effective speed.

It follows that H264 really is not the way forward at 32 Mb/s HEVC two pass or crf=23 in single pass you get files that are 20% or less of the size and work well if you have a 4K HEVC accelerated player like I do. At this bitrate is also very easy to stream over your wireless LAN even at mediocre quality. Unfortunately YouTube will reject your HEVC files and require H264 or VP9.

Google plot for 4K world domination

Google did not want to incur more royalties so they pushed out HEVC to use the open source VP9 as they did years ago with Vp8.

VP9 is at least in the Mac version very slow and seems fairly amateurish. They have been succesful with Android Tvs that have YouTube as a prime source of 4K content because the YouTube app does not work in 4k on Tv sets unless it can decode VP9. This is clearly only a commercial plot as all TVs can play H264 and YouTube wants to reach as many people as possible with 4K therefore keeping bandwidth below 20 Mb/s and accessible to the higher end of DSL connections not just fiber so that they can push their ads to the masses, however it also means that your video will look pretty pathetic on YouTube unless  you use a VP9 capable browser or Tv set or android to box to watch it.

At time of writing the only android box that can decode Vp9 is the Nvidia Shield Tv so if you want to watch YouTube 4K videos at 18 Mb/s Vp9 there is at least one choice.

http://shield.nvidia.com/android-tv

Also the Roku and Kindle fire Tv support YouTube 4K but don’t have Kodi so I would not consider them

 

 

 

 

 

 

 

 

 

 

Blog Posts Coming Soon

These days I don’t have too much time to write nevertheless there are some exciting articles coming.

Nauticam is sending me a few items for testing that include the Panasonic LX100 housing and the new Nauticam wet lens.

The nauticam wet lens has been in the works for a very long time and is going to be released end of September, I will compare performance with the Inon lenses and report back finding.

I am also going to review the new Leak Sentinel v4 that has a number of promising updates.

But the first post will be about lenses for micro four third cameras. The system is very flexible and so is the Nauticam Port system there are many lenses supported and getting the right one is a bit of a headache for newcomers to the ILC space, I will try and make it simple and suggest a way forward so stay tuned.

Sale is on

Am finally selling my Sony RX100 Mark II and accessories with Nauticam housing plus Inon UWL-100 28AD with domeams neoprene cover

All for £1,200 send a comment if interested

All items with Original boxes and parts as shown

Sony RX100 Mark II with Inon UWL-100 28AD + Dome
Sony RX100 Mark II with Inon UWL-100 28AD + Dome

Pictures are on Flickr happy to address any questions

Price for items sold separately

Sony RX100 Mark II plus accessories (Filter holder, ND, filter, pouch, extra battery) £300

Inon Wet Fisheye lens UWL-100 28AD with Dome and neoprene cover and M67 adapter £450

Nauticam RX100 II Housing in excellent condition with no scratch on port or LCD viewer £500

THANKS FOR LOOKING THE ITEMS HAVE NOW BEEN SOLD

UHD 4K not yet a viable option – at least for me

It has been a few months now that I have experimented with my UHD set up and I have been able to draw a few conclusions.

My Tv is a Sony KD-55X8505B and as 4K player I use the Tv itself for Netflix (one of the few places you can find 4K content) I have not tried amazon 4K. In order to play your own files you can either connect your TV to a NAS or use a small box.

Sony KD-55X8505B

I went for the Minix X8H-Plus as a media player to stream from my NAS as the client in the Sony TV is pretty basic.

The minix has hardware accelerated HEVC decoding so it will work as a player for any 4K TV that has no compatible codec. A word of warning though the Netflix and Youtube client in the android box are not 4K compatible.

I have an FTTC connection with 32 mbps speed that is more than the recommended 25 mbps for Netflix UHD so I gave it a go and the results are spectacular, not just the Tv shows (house of cards, better call saul, Marco Polo) but the short features on deserts and flowers are amazing. All of this content is HEVC so 25 mbps or less for 4K UHD.

I then tried tears of steel https://mango.blender.org/

Tears of Steel is a short series shot in 4K using the old school H264 codec as the Panasonic GH4 and LX100 do at 100 mbps, the files encoded at 72 mbps end up with a massive 6.12 GB for just 12 minutes.

H265 vs H264

On average at similar parameters the same source compressed with H265 results in 65% space saving compared to H264.

Now that is quite a lot so if you think about it your 100 mbps GH4 file could shrink to 35 mbps which is just a little more than AVCHD progressive and less than Sony XAVC 50 Mbps you can still record it with a class 6 card though class 10 would be appropriate.

Cameras and Editors

Today only Samsung NX series can encode HEVC and for editing there are no programs on Mac using HEVC, possibly something exists for windows. But it is fair to say we are a long way away from main stream.

Why is HEVC important? With H264 the files are too bit and if compressed to youtube average of 25-30 mbps they do not look that good you wonder if it is actually worth it.

A large 70 mbps file require a very fast wireless ac router close to the player or simply using a memory card to play your videos locally. This is not user friendly.

I believe it will take at least another year to see HEVC included in cameras and editors if not longer, until then for me it makes no sense to invest in a 4K set up as the file produced are just too large to be shared so remain in the realm of semiprofessional to professional users.

Video Feature Sony RX100 Mark II in Malta

Following from my previous post I managed to get together a clip out of the 5 dives I did

The first day was somewhat plagued by visibility a bit lower than the norm for the location but the second day was fabulous

For this trip I brought with me the Inon UWL-H100 and the red push on filter from deep roof H20 and the Inon UCL-330 as I was expecting medium size fish and nothing really small

Here is the outcome

I am quite happy how things turned out so let me share the settings with you

First I shot most of the footage in 25p AVCHD mode only some small sections are shot at 50p and actually I did not need to slow down any of the material.

For the wide shots I used steady shot in normal mode and shutter priority at 1/50th. With the filter on I had auto white balance with tint correction G2 A1. I noticed that the camera was giving red tint in some situation and so added a bit of green back. The Amber correction instead is for the RX100 itself the camera does not have vibrant yellow and is a bit blue.

Tunas
Tunas – AWB with filter

For the first time I use creative mode changing the standard contrast to -3 in order to prevent crushing of blacks.

Exposure was set all along to -1/3 and metering to multi area with AUTO ISO limited 160-800.

I think the results are so good that in fact I have performed no colour correction to any shots in ambient light.

Opening the tuna farm
Opening the tuna farm – AWB with filter

For shots with lights I set up first colour temperature to 6500K and A1 to match the lights but then in some of the far shots this resulted a bit cold so I adjusted very slightly in post the temperature.

Seahorse
Seahorse – AWB UCL330

Only 40″ are adjusted in the whole video in essence is as shot and the editing took me half hour.

In cave
In cave –  AWB no filter

I did a bit of analysis and the camera was operating for most at ISO200 with aperture around f/3.5 – f/4.0 which is really the sweet spot of the lens.

I did have some challenges using the UCL330 for some nudibranches  that really required a stronger lens so they look a bit small, there was also surge so I had to fight with focus problems but all in all very happy.

Nudibranch
Nudibranch – AWB UCL330

The longer working distance of the UCL330 (20-30 cm or 8″ to 1′) proved challenging on walls as you are too far to hang on to anything or use a stick. I will bear this in mind in the future.

For the close up shots I used steady shot active.

I also wanted to say that a few times the camera did manage to white balance properly however the results were not exciting and frankly not worth the hassle. Using the filter is just so much better with the auto white balance.

Tweaking the Sony RX100 Mark II Video Performance

I am currently in Malta for few days relaxing and I manage to squeeze in some dives. The Mediterranean sea is nothing sensational (from a pure diving point of view) but does offer clear water, and some brisk thermoclines, and a combination of algae, blue water, caves and silvery fish that is challenging on the dynamic range of our little RX100.

The purpose of this trip is mostly to refine the video settings and go more in depth in few topics. I wanted to try specifically the following:

  • Metering modes
  • Creative modes
  • Stabiliser modes
  • Tracking focus
  • Medium size fish portraits
  • White balance
  • Caves and low light

Some of my settings will be the same and I am not intending to changed them those are:

Auto ISO: 160 – 800

DRO: Auto

Starting off with metering, the first attempt was to try and use the camera on 0 exposure compensation with centred weighted average metering.

Entering Cave Fairly Bright
Entering Cave Fairly Bright

Pretty soon I realised this gave issues of banding of the blue water, this was apparent not only in backlit shots but also in normal wide angle of fish in specific cases. So after dive number 1 I changed it to the standard -0.3 from dive 2.

I set a new creative style with contrast at -3 in the hope to recover detail and seem to be working fine with the shots still having plenty of contrast.

Lowered Constrast on -3
Lowered Constrast on -3

I also tried spot metering for close up but it makes no sense the video lights are too wide and ended up with burned highlights at the edges of the frame so back to centred weighted average for close up shots.

Spot metering
Spot metering

So when it comes to metering my settings are:

Wide angle: multi area

Close up: centered weighted average

I did some tests with stabiliser in steadyshot mode, this gives back some field of view and the lens offers 100 degrees diagonal and 90 horizontal, I actually think a bit more anyway with fairly stable conditions this worked fine. At longer focal length for close up I am still using active mode.

Schooling Fish 100 fov
Schooling Fish 100 fov

I have a +3 diopter for this test as I realised in my last still trip I don’t have a lens for medium size fish, the lens worked very well and I also tried the camera tracking focus but it seems it won’t work with fireworms or similar. So either keep normal focus or manual with peaking.

Tracking focus fail
Tracking focus fail
Rock FIsh UCL 330
Rock FIsh UCL 330

White balance has been a subject of discussion, I did manage this time to white balance a few times but to be honest it was not worth the effort there is a better correction of the purple hue of the filter but this can be corrected setting Green to 1 or 2 in AWB. I also changed the AWB to include a correction with Amber 1 as per examples. Very happy with the results I think this is the final set up with this filter lacking a proper orange filter.

AWB corrected
AWB corrected

Shooting in low light was rewarding with ISO maxed out at 800. I am becoming less and less a fan of video lights in cave due to the amount of backscatter am getting. I think I will default at using the lights as dive torches instead of wide beams of even leaving them off for effect.

Backscatter
Backscatter
Cave in natural light
Cave in natural light