San Francisco/Bay Area Private Workshop, 4th of March, 2 places left.

I’m looking to fill the last 2 places on this intermediate to high level full day workshop. Please note: All participants signed up so far are seasoned pros with at least a decade of professional experience. Topics covered will be:

Scene Files and Paint Settings – Gamma Curves, Dynamic Range, Matrix and Color.
Gain and ISO, what do these really mean. Understanding the signal to noise ratio.
S-Log, S-Gamut and Exposure Indexing.
LUT’s and Looks, LUT creation and LUT use.
File handling and backup.
Grading introduction including color managed workflows such as ACES.
HDR – Introduction to HDR, what we need to know and how will it effect us.

This is a private workshop and there is a fee to attend. Please use the contact form if you are interested.

Sony FDR-X3000 4K Action Cam – built in gimbal.

One of the cameras I used a lot in Norway is the new Sony FDR-X3000 action cam. What’s different about this POV camera is that the lens and sensor are actually mounted in an internal miniaturised gimbal. This really does work and helps stabilise the image.

There is also a tiny bluetooth monitor that you can wear on your wrist to view the pictures and control the camera. The image quality you get from these tiny cameras really is quite amazing. Take a look at the video to find out more and see some sample footage.

PXW-FS5 Native ISO’s

This is as much for my benefit as yours as I can never remember what the native ISO (0dB) is for each of the gamma curves in the FS5.

Standard 1000 ISO
Still 800 ISO
Cinegamma 1  800 ISO
Cinegamma 2  640 ISO
Cinegamma 3  1000 ISO
Cinegamma 4  1000 ISO
ITU709 1000 ISO
ITU709(800) 3200 ISO
S-Log2 3200 ISO
S-Log3 3200 ISO

Using dB and setting it to 0dB really is so much easier with this camera!

The new Sony FS7 zoom lens, the Sony SELP18110G.

AJC03714-1024x681 The new Sony FS7 zoom lens, the Sony SELP18110G.
Sony SELP18110G servo zoom lens.

When Sony launched the FS7 II they also launched a new lens to go along with it. The previous zoom lens that was bundled with the FS7 was the SELP28135G, a 28-135mm f4 zoom lens that would work with Super 35mm, APS-C and full frame cameras. While generally well received this lens is not without it’s problems. For a start it’s not really wide enough for use as a general purpose lens on an APS-C or Super 35mm sensor. The other problem is that the zoom is very slow. Even when set to manual zooming in and out takes a long time. You turn the zoom ring and then have to wait for the lens to catch up.

The new lens is a wider 18mm to 110mm f4 lens. This is a really useful zoom range for a Super 35mm camera. But the new lens can only be used on S35mm and APS-C cameras. It can’t be used with full frame cameras like the A7s in full frame mode.

AJC03718-1024x681 The new Sony FS7 zoom lens, the Sony SELP18110G.
The front element of the Sony SELP18110G.

But what about the zoom speed? Well this has been addressed too. On the 28-135mm lens the zoom function is electronic. There is no mechanical connection between the zoom ring and the optics of the lens. The 18-110 has a proper mechanical connection between the zoom ring and the internal lenses, so now you can crash zoom in and out as fast as you want. In addition the zoom servo motor is much faster and motorised zooms take place much more rapidly. One downside to this is that it’s a bit harder to control the zoom speed. You can do slow creeping zooms if you are very careful with the cameras zoom rocker, but it’s hard to do. The difference in pressure on the zoom rocker between creeping zoom and medium speed is tiny. The lens tended to change zoom speed quite quickly. While it is indeed very nice to have a variable speed motorised zoom, don’t expect the fine degree of control that you get from admittedly more expensive traditional ENG lenses. Lets face it this lens is only around £3K/$5K which is remarkable cheap for a parfocal s35mm zoom. Take a look at the video below for an idea of the zoom speeds etc.

Is it really parfocal? Well yes, it does seem to be parfocal. I only had the lens for a morning to play with, but in all my tests the focus remained constant throughout the zoom range.

So, what about focus? Like the 28-135mm lens there is a nice big focus ring that slides fore and aft.

AJC03723-e1487017741838 The new Sony FS7 zoom lens, the Sony SELP18110G.
Focus, zoom and iris rings on the SELP18110G.

In the rear position the focus is manual and there are calibrated focus markings and end stops. You get about 180 degrees of focus travel from 0.95m (3.1ft) to infinity (in autofocus you can focus slightly closer when the lens is at the wide end). The focus ring has 0.8mm pitch teeth for use with most standard follow focus units, although this gear ring is very close to the end of the lens, so it may be tricky to use if you have a matte box in place. Breathing is very well controlled and barely noticeable unless going through very large focus throws. Out of focus Bokeh isn’t bad either, I didn’t observe any nasty surprises in the limited time I had to play with the lens.

Bokeh-1024x576 The new Sony FS7 zoom lens, the Sony SELP18110G.
Frame Grab. Near and far out of focus bokeh is reasonable on the Sony SELP18110G. Click on the image to view a full size copy.

Sharpness and flare. The lens appears to be nice and sharp at the wide end but just a touch soft at the long end. It’s not bad overall but when shooting at 4K I could just about detect the lens becoming marginally softer as I zoomed in. The sample I had was a well used pre-production prototype, but I’m going to guess that the production lenses won’t be hugely different. Shooting the roof of a house against a bright sky revealed only a small amount of flare, certainly nothing out of the unusual for a zoom lens.

18110-110-1024x576 The new Sony FS7 zoom lens, the Sony SELP18110G.
Frame grab from the Sony SELP18110G at 110mm. Click on the image to view a full size copy.
18110-18-1024x576 The new Sony FS7 zoom lens, the Sony SELP18110G.
Frame grab shot with Sony SELP18110G at 18mm. Click on the image to view the full size image.

Overall I really like this lens. It even has a support point at the front of the lens body for additional stability. While f4 isn’t the largest of apertures it is quite usable and even wide open the lens performs well. For the money it is a lot of lens. I think we need to be realistic with our expectations for zoom lenses and large sensors. Bigger zoom ratios require bigger lens elements if we want to maintain a constant aperture. Bigger lens elements cost more to produce.

AJC03729-e1487018834354 The new Sony FS7 zoom lens, the Sony SELP18110G.
Underside of the Sony SELP18110G showing the extra lens support points. A lens foot that attaches to the rear mounting is included with the lens.

One advantage Sony have over the competition is that it’s easier to make zoom lenses for the very short flange back distance of the E-Mount cameras compared to the deeper flange back of PL or Canon mounts. The closest competition to this lens is the Canon 18-80mm T4.4 (f4 ish) which is a fair bit more expensive (£4K/$6K). If you want a similar zoom range then you’re looking at the beautiful  Fujinon 20-120 T3.4 at around £14K/$19K.

Northern Colour – new Northern Lights video.

It’s that time of year again. After another simply amazing trip to northern Norway I am pleased to be able to share with you my latest Aurora video. It was shot with a Sony A7s and a Sony A6300. The lenses used were a Sigma 20mm f1.4 art lens. An older Sigma 20mm f1.8, a samyang 14mm f2.8 and a Sony 16mm f2.8 pancake lens. A Metabones Speedbooster Ultra was used on the A6300. For the slider shots I used a home built track (made so it fits my suitcase perfectly) and a Cinetics Cinemoco controller. Hope you enjoy it.

Not all raw is created equal. Log may be better

This keeps cropping up time and time again.

Unfortunately every now and again a new term or buzzword comes along that gets taken as a holy grail term. Two that come to mind right now are log and raw. Neither log, nor raw, are magic bullet solutions that guarantee the best performance. Used incorrectly or inappropriately both can result in inferior results. In addition there are many flavours of log and raw each with very different performance ranges.

A particular point in case is the 12 bit raw available from several of Sony’s mid range large sensor cameras, the FS700, FS7 and FS5.

Raw can be either log or linear. This particular flavour of raw is encoded using linear data.  If it is linear then each successively brighter stop of exposure should be recorded with twice as many code values or shades as the previous stop. This accurately replicates the change in the light in the scene you are shooting.  If you make the scene twice as bright, you need to record it with twice as much data. Every time you go up a stop in exposure you are doubling the light in the scene. 12 bit linear raw is actually very rare, especially from a camera with a high dynamic range. To my knowledge, Sony are the only company that offer 14 stops of dynamic range using 12 bit linear data.

There’s actually a very good reason for this: Strictly speaking, it’s impossible! Here’s why: For each stop we go up in exposure we need twice as many code values. With 12 bit data there are a maximum of 4096 code values, this is not enough to record 14 stops.

If stop 1 uses 1 code value, stop 2 will use 2, stop 3 will use 4, stop 4 will use 8 and so on.

STOP:  CODE VALUES:  TOTAL CODE VALUES REQUIRED.

+1          1                                   1
+2          2                                   3
+3          4                                   8
+4          8                                   16
+5          16                                32
+6          32                                64
+7          64                                128
+8          128                             256 Middle Grey
+9          256                             512
+10       512                             1,024
+11       1,024                          2,048
+12       2,048                         4,096
+13       4,096                         8,192
+14       8,192                         16,384

As you can see from the above if we only have 12 bit data and as a result 4096 code values to play with, we can only record an absolute maximum of 12 stops of dynamic range using linear data. To get even 12 stops we must record the first couple of stops with an extremely small amount of tonal information. This is why most 14 stop raw cameras use 16 bit data for linear or use log encoded raw data for 12 bit, where each stop above middle grey (around stop +8) is recorded with the same amount of data.

So how are Sony doing it on the FS5, FS7 etc? I suspect (I’m pretty damn certain in fact) that Sony use something called floating point math. In essence what they do is take the linear data coming off the sensor and round the values recorded to the nearest 4 or 8. So, stop +14 is now only recorded with 2,048 values, stop +13 with 512 values etc. This is fine for the brighter stops where there are hundreds or even thousands of values, it has no significant impact on the brighter parts of the final image. But in the darker parts of the image it does have an impact as for example stop +5 which starts off with 16 values ends up only being recorded with 4 values and each stop below this only has 1 or two discreet levels. This results in blocky and often noisy looking shadow areas – a common complaint with 12 bit linear raw. I don’t know for a fact that this is what they are doing. But if you look at what they need to do, the options available and you look at the end results for 12 bit raw, this certainly appears to be the case.

Meanwhile a camera like the FS7 which can record 10 bit log will retain the full data range in the shadows because if you use log encoding, the brighter stops are each recorded with the same amount of data. With S-Log2 and 10 bit XAVC-I the FS7 uses approx 650 code values to record the 6 brightest stops in it’s capture range reserving approx 250 code values for the 8 darkest stops. Compare this to the linear example above and in fact what you will see is that 10 bit S-Log2 has as much data as you would expect to find in a straight 16 bit linear recording below middle grey (S-Log 3 actually reserves slightly more data for the shadows). BUT that’s for 16 bit. Sony’s 12 bit raw is squeezing 14 stops into what should be an impossibly small number of code values, so in practice what I have found  is that 10 bit S-log has noticeably more data in the shadows than 12 bit raw.

In the highlights 12 bit linear raw will have more data than 10 bit S-log2 and S-Log3 and this is borne out in practice where a brightly exposed raw image will give amazing results with beautiful highlights and mid range. But if your 12 bit raw is dark or underexposed it is not going to perform as well as you might expect. For dark and low key scenes 10 bit S-Log is most likely going to give a noticeably better image. (Note: 8 bit S-log2/3 as you would have from an FS5 in UHD only has a quarter of the data that 10 bit has. The FS5 records the first 8 stops in  8 bit S-log 2 with approx 64 code values, S-Log3 is only marginally better at approx 80 code values. 12 bit linear outperforms 8 bit log across the entire range).

Sony’s F5 and F55 cameras record to the R5 and R7 recorders using 16 bit linear data. 16 bit data is enough for 14 stops. But I believe that Sony still use floating point math for 16 bit recording. This time instead of using the floating point math to make room for an otherwise impossible dynamic range they use it to take a little bit of data from the brightest stop to give extra code values in the shadows. When you have 16,384 code values to play with you can afford to do that. This then adds a lot of extra tonal values and shades to the shadows compared to 10 bit log and as a result 16 bit linear raw will outperform 10 bit log across the entire exposure range by a fairly large margin.

So there you have it.  I know it’s hugely confusing sometimes. Not all types of raw are created equal. It’s really important to understand this stuff if you’re buying a camera. Just because it has raw it doesn’t necessarily mean an automatic improvement in image quality in every shooting situation. Log can be just as good or possibly even better in some situations, raw better in others. There are reasons why cameras like the F5/R5 cost more than a FS5/Shogun/Odyssey.

Camrade CB-HD camera bag.

CAM_CAM-CB-HD-MEDIUM_3_26109 Camrade CB-HD camera bag.I’ve been using Camrade bags for years. They are tough, protect my gear well without being heavy and clunky like pelicases and other hard shell cases. In addition they don’t scream “expensive equipment here”. They just look like large holdalls.  One of the best features is the use of dividers, pads and inserts that are attached with velcro that allow you to reconfigure the bags for different applications.

CAM_CAM-CB-HD-MEDIUM_4_26110 Camrade CB-HD camera bag.
Camrade CB-HD equipment bag with reconfigurable velcro dividers and pads.

One thing I often do is carry my camera in a standard carry-on bag when I’m flying. Meanwhile my tripod goes in the camera bag in the hold. When I get to my destination the tripod comes out of the camera bag, I re-arrange the dividers and the camera then lives in the camera bag until I need to fly again. This is so easy to do with the Camrade bags. Although the bags look like soft bags they are extremely ridged. The sides, top and bottom have hard inserts in them that can withstand very large loads, they are strong enough for you to sit on them without collapsing. The bags have strong carry straps and come with a high quality, removable camera strap. There are mesh pockets on the outside as well as on the inside of the lid for those little accessories and bits and pieces that would otherwise get lost. Another bonus is a 90% white card for white balance and use as an exposure reference.

Here’s a video of the medium size Camrade CB-HD bag, designed to take the PXW-FS7 or other similar digital cinema cameras. It’s a bit taller than some of their other bags so perfect for cameras rigged up with base plates and matte boxes.

 

What is XOCN? Why is it so good, why do we need it?

This time last year I was just starting to earn about a new codec from Sony called XOCN (eXtended Original Camera Negative). XOCN is currently only available with the Sony F5/F55 and the new AXS-R7 raw recorder. Sony’s original R5 raw recorder takes 16 bit sensor data and applies a very mild amount of compression before recording the sensor data as linear raw. I have never seen any compression artefacts when using the 16 bit linear raw and it really is an amazing format to work with. So much so that I will always use it whenever possible.

But now as well as 16 bit linear raw the R7 can record 16 bit linear XOCN. Now, I’ll be completely honest here, I’m really not sure what the difference is between raw and XOCN. As far as I can tell XOCN is very, very similar to raw but sufficiently different to raw to avoid infringing on patents held by other manufacturers for compressed raw. XOCN is more highly compressed than Sony’s raw, but in every test I’ve done I have found it hard to spot any compression problems or any significant difference between XOCN and the original 3:1 raw.

So, I hear you ask…. “If it’s really that good what don’t we just do away with XAVC and use XOCN?” Well that is a good question. It all depends on processing power. XAVC is a traditional codec so inside the codec is a normal video image, so the only thing a computer has to do to play it back is uncompress the codec. XOCN is a compressed wrapper that contains sensor data, in order to view the image the computer has to uncompress the data and then it has to construct the image from the data. So you need a really good graphics card in a decent computer to work with XOCN. But if you do have a decent edit or grading workstation you should find XOCN straight forward to work with, it doesn’t require specialist cards to accelerate the decoding as Red raw does.

The key benefit that XOCN brings over traditional video is that it is 16 bit. 10 bit video is pretty good. In a 10 bit video you have almost 1000 tonal values, not bad when you consider that we have been using 8 bit for decades with only 235 shades. But 16 bit brings the potential for a whopping great 65,535 shades. This starts to make a big difference when you are extensively manipulating the image in post production. Any of you that are in to photography will know that you can push and pull a 16 bit raw photograph far, far further than an 8 bit jpeg. 16 bit video is no different.

But what’s really amazing about XOCN is you get almost all the benefits of linear raw but in a file size smaller than the same resolution 10 bit ProResHQ. If you use XOCN-LT the files are roughly half the size of ProResHQ. This means your media lasts a sensible amount of time and backups, transfers and archiving are all much easier, much faster than with uncompressed raw. Sony’s 3:1 compressed raw from the R5 has always been pretty easy to deal with. XOCN is even easier. Using XOCN-LT you can squeeze well over 2 hours of 16bit 4K on to a 512GB AXS card! In fact the file sizes are only marginally larger than XAVC class 480.

xocn-data-rates-1024x276 What is XOCN? Why is it so good, why do we need it?

The reduction in data rates becomes really significant if you shoot at high frame rates. As 50p and 60p productions become more common XOCN allows production companies to shoot 60fps with the benefits of 16 bit data but with files sizes barely any bigger than 24fps ProResHQ. If you have a Sony PMW-F55 you can shoot at 120fps in 4K using XOCN and the files are twice as big as 24fps raw.

For further information on XOCN please take a look at this page from Sony, it’s very informative and has a very good example of why 16 bit data is important, especially if you are shooting for HDR.

https://pro.sony.com/bbsc/ssr/show-highend/resource.solutions.bbsccms-assets-show-highend-f55xocn.shtml

Camera setup, reviews, tutorials and information for pro camcorder users from Alister Chapman.