Tag Archives: dark

Low Light Shooting – S-Log3 or S-Cinetone?

A fundamental aspect of electronic cameras is that the bulk of the noise comes from the sensor. So the amount of noise in the final image is mostly a function of the amount of light you put on to the sensor v the noise the sensor produces (which is more or less constant). This is known as the signal to noise ratio, often abbreviated to SNR.

Whether you use S-Log3 or S-Cinetone, even though the base ISO number the camera displays changes the sensitivity of the camera is actually the same, after all we are not changing the sensor when we change modes. In fact if you set the camera to dB you will see that in custom mode the base for both S-Cinetone and S-log3 (and every other gamma curve) is always 0dB.

All we are changing when we switch between S-Cinetone and S-Log3 is the gamma curve – which is a form of gain curve. The base ISO number changes between S-Log3 and S-Cinetone because if you were using an external light meter this would be the number to put into the meter to get the “correct” exposure, but the actual sensitivity of the camera remains the same.

First let’s think about what is happening at the base ISO of each if we were to use an external light meter to set the exposure…..

If we shoot at S-Cinetone and use the 320 ISO value in the light meter the aperture will be a little over a stop more open than if you shoot with S-Log3 and use 800 ISO for the light meter. So when using S-Cinetone at the base ISO there is a little over twice as much light going on to the sensor compared to S-Log3 at the base ISO and as a result the S-Cinetone will be much less noisy than the S-Log3. Not because of a sensitivity or noise performance difference but simply because you are exposing the sensor more brightly.

And if we use the SAME ISO value for S-Cinetone and S-Log3?

So now think about what might happen if you were to put 400 ISO into your light meter and use the values for shutter and aperture the meter gives and shoot with either S-Cinetone or S-Log3 using the very same aperture and shutter settings so that the same amount of light is hitting the sensor for both. The result will be that the amount of noise in the resulting image will be broadly similar for both and the same would happen if you were to use, let’s say, 4000 ISO (assuming you switch to high base for both).

There will tend to be a bit more noise in the S-Log and CineEI at the default settings, because by default NR is turned off in CineEI. But with the same in camera NR settings, again both the S-Log3 and S-Cinetone will have very, very similar noise levels when the sensor receives the same amount of light.

What about when there isn’t enough light?

So – when you are struggling for light, both will perform similarly from a noise point of view. BUT where there may be a difference is that with S-Cinetone all your image processing is done before it is compressed by the codec and what you see in the viewfinder is what you get. With S-Log3 the “underexposed” image gets compressed and then you will need to process that in post and when you add your post corrections this will be to the recorded image + compression artefacts so there will always be a lot of uncertainty as to how the final image will come out.

Personally I tend to favour S-Cinetone for under exposed situations. Generally if it’s under exposed dynamic range isn’t going to be an issue. S-Cinetone also spreads what image information you do have over a greater range of code values than S-Log3 and this may also help a little. But there is no right or wrong way and any differences will be small.

Using an FS5 to shoot in low light – what can I do?

The PXW-FS5 is a pretty good camera overall. Compared to cameras from 6 or 7 years ago it’s actually pretty sensitive. The exposure rating of 800 ISO for the standard rec-709 picture profile tells us that it is a little more than twice as sensitive as most old school shoulder cams. But it also suggests that it is only around half as sensitive as the king of low light, the Sony A7S. The A7S is so sensitive because it’s sensor is 1.5x bigger than the sensor in the FS5 and as a result the pixels in the A7S are almost twice the size, so are able to capture more light.

So what can you do if shooting in low light? 

The most important thing to do is to make the optical system as efficient as possible. You want to capture as much of the available light as you can and squeeze it down onto the FS5’s sensor. If you take a fast full frame lens and use it in conjunction with a Speed Booster type adapter you will end up with similar performance to using the same lens, without the speed booster on an A7S.

This is because the lens has a fixed light gathering capability. Use it on an A7S and all of the captured light is passed to all of those big pixels on the sensor. The light is split evenly across 4K’s worth of pixels.

Use it on an FS5 with a speedbooster and the same thing happens, all of the light is compressed down, which makes it brighter and all of this now brighter light falls on 4K’s worth of pixels. The smaller pixels are about half as sensitive, but now the light is twice as bright, so the end result is similar.

metabones_mb_spom_m43_bm3_speed_booster_ultra_0_71x_1259766-1024x1024 Using an FS5 to shoot in low light - what can I do?
A speedbooster adapter such as the Metabones makes a huge difference in low light. But you MUST use a full frame lens.

The biggest performance gains are to be had from using a very fast lens and then making sure all the light from the lens is used, none wasted. Anything slower than f2.8 will be a waste. If you are thinking of using the Sony f4 lens for very low light… well frankly you may as well not bother. The lens is THE most important factor in low light. When I go up to Norway to shoot the Aurora I use f1.4 and f1.8 lenses.

What about Picture Profiles?

The standard picture profile isn’t a bad choice for low light but you might want to look at using cinegamma 3. Although with a low light, low contrast scene none of the picture profiles will be significantly different from the others with the exception of PP2, PP7, PP8 or PP9. None of the profiles make the camera more sensitive, the sensitivity is governed by the sensor itself and all the profiles do is alter the way gain is distributed across the image.

PP2 will crush your shadows giving less to work with in post. The log curves in PP7,8,9 will roll off the darkest parts of the image, again giving you less in post. So I would probably avoid these.

For color I suggest using the Pro colour matrix. This works well for most situations and it will help limit the noise levels as it keeps the saturation fairly low keeping the noisy blue channel in check.

Gain or ISO?

I recommend you set the camera to gain rather than ISO as the ISO’s for each each gamma curve are different, so it can be difficult to understand how much gain is being added, especially if you are switching between gamma curves. Use gain and you will have a good idea of the noise levels as every time you add +6dB the image becomes one stop brighter and you double the noise in the image, +12 dB is 2 stops brighter and 4x noisier than 0dB etc. ISO is an exposure rating, it is not a sensitivity measurement. But don’t use too much gain or too high an ISO as this will affect you ability to use some of the very good post production noise reduction tools that are available.

Noise and Noise Reduction.

If shooting in very low light then you are quite probably going to want to use some noise reduction tools in post production. “Neat Video” works very well at cleaning up a noisy image as do the various NR tools in the paid versions of DaVinci Resolve.  These post production  tools work best when the noise is clean. By that I mean well defined. When using any of the 709 or Cinegamma curves a bit of gain can be used, but I wouldn’t go above 12dB as above this the NR starts to introduce a lot of smear and this than makes it hard for any post production NR processes like Neat Video to do a decent job without the image turning into a blurry mess. So don’t go crazy with the gain or use very high ISO’s as the post production NR won’t work as well on footage that already has a lot of in camera NR applied.

And if you can add a little light-

If you are adding any light use a daylight balanced light where you can. Video cameras are least sensitive in the blue channel. If you use a tungsten light which is predominantly warm/red to get a good white balance you have to increase the gain of the cameras least sensitive and as a result most noisy blue channel. This will add more noise than if you use a daylight balance light as for daylight you need less gain in the noisy blue channel.

There is no miracle cure for shooting in very low light levels. But with the right lens and a speedbooster the FS5 can do a very good job. But just in case yo haven’t worked it out already, I’ll say it one more time: The lens is the most important bit! Beyond this your next step would be adding an image intensifier for that green night vision look.

Anatomy of a shot. Night Scene in Arctic Norway – Fujinon lenses, Stella Lights.

I have just return from one of the most challenging shoots I have been involved in. The shoot took place over 5 days in and around Tromso in Norway. The aim was to gather footage to show off the capabilities of a new type of 4K TV from Phillips.

We shot the Northern Lights, we shot dog sledding , snow mobiles, shots of the city and sailing on the fjords. Each part of the shoot had many challenges and a lot of the shoot took place at night and at night the crew slept in cabins, tents and on the yachts. Shooting from the ice and snow covered deck of a yacht in temperatures well below zero is not something I enjoyed. And to top it all off the weather was pretty grim fro most of the shoot. Heavy snow showers, freezing temperatures and towards the end strong winds.

Because image quality is paramount for this project I choses to use the best lenses I could, but at the same time space and time constraints dictated that zoom lenses would be desirable. We were shooting 16 bit raw as well as XAVC class 480 on my PMW-F5 and some pick-up shots in UHD XAVC-L on a PXW-FS5. For the PMW-F5 the primary lens was the Fujinon Cabrio XK6x20, 20-120mm PL zoom and to ensure we had similar looking images from the FS5 I used the new Fujinon XF 18-55mm. I have to say that I’m quite in love with both of these lenses.

fujinon-xk6x20-20-120mm-t3-5-pl-mount-lens-cc1-e1490981959479 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
Fujinon Cabrio XK6x20 PL mount cinema zoom. A beautiful lens!

The Cabrio 20-120 is a beautiful lens and it’s really nice to have a servo zoom that is truly parfocal. The 20-120 produces really nice images even in the most challenging of conditions and at T3.5 it’s reasonably fast throughout the entire zoom range. This was the lens that I used for the majority of the shoot, in particular for the many night scenes we shot. The E-Mount 18-55 on the FS5 produces images that matched really well with the bigger lens and camera. This is a combination I would love to use on more shoots where the budget will allow.

One particular scene that we had to shoot was particularly challenging. It was a set up shot of a night time arrival of a couple of snowmobiles at a Sami camp site. The Sami people are the indigenous people of Northern Norway and they have a particular style of tent know as a Laavu which is similar to a teepee or wigwam. The idea behind the shot was to have the snow scooters arriving with headlights blazing and for the drivers to then enter the tent lit only by the light of a campfire inside the tent. At the time of the shoot it was snowing heavily and was totally dark. Turn off the lights of the snowmobiles and you could not see a thing.

A007C001_170317I9snwscter-wide-1.-e1490980652498 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
Wide shot of the snowmobiles arriving at the camp in the dark.

While modern cameras like the F5 are very sensitive, the light of a campfire inside a tent will not adequately light a scene like this on it’s own. I didn’t want a totally dark background, so I decided that I would subtly light the trees of the forest that we were in to add some drama and give some depth to the background and a sense of being in a forest.

In-tent-wide-e1490980747645 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
A slightly closer shot of the tent with backlit trees behind it.

As we were travelling continuously on this shoot there was no space for a large or complex lighting kit and the remote location meant we needed battery powered lights. In addition I knew before we left that there was a chance of bad weather so I needed lights that would work whatever mother nature decided to throw at us.

snw-scter-start-e1490980892561 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
A snow scooter comes into the shot. You can see just how heavily it was snowing in this shot.

I decided to take a set of 3 Light & Motion Stella battery powered LED lights. It’s just as well I had the Stella lamps as on top of all the other difficulties of the shoot the weather decided it was not going to play ball. We had to shoot the scene (and much of the shoot) in the middle of a snow storm. Fortunately the Stella lights are completely waterproof, so I didn’t need to worry about rain or snow protection. Just set them up turn them on and use the built in dimmer to set the light output.

To light the scene I set up a Stella Pro 5000 in the woods behind the Sami tent, aimed through the trees and pointed directly towards the camera. I chose to backlight the trees to provide a sense of there being trees rather than lighting them. I felt this would look less lit than throwing a ton of light into the forest from the front and I’m pleased with the result.

20170317_201335-e1490980965481 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
A Light & Motion Stella Pro 5000 was used to back light the trees and tent. The heavy snow was no problem as the light is totally waterproof.

The Stella Pro 5000 is very bright for a compact battery operated light, it’s 5000 lumen 120 degree output that is pretty close to what you would get from a 200W HMI, it’s very bright. It has a very high CRI and gives out great quality daylight balanced light.  It was positioned so that the light itself was behind the tent on a small bank, about 20m back in the woods. You couldn’t see it in the shot, but the light coming through the trees created shafts of light in the snow and the trees appeared as silhouettes. It added depth and interest to what would have otherwise been a near totally black background.

20170317_203855-e1490981224538 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
Light & Motion Stella 2000 used to light the forground, again the lamp is waterproof so bad weather is no problem.

Then to provide a small amount of light so that we could see the riders of the snow scooters as they walked to the tent I used a Stella 2000. I didn’t really want the light from this lamp to be too obvious as this would really make the scene look “lit”. I didn’t need the full 2000 lumen output so I used the built in dimmer to reduce the output to around 70%.

The third light was a small Stella 1000 and this was placed inside the tent with a scrunched up orange gel. The Stella 1000 would typically be used as a camera top light, but it’s full dimmable and produces a very high light quality, making it suitable for many applications. The creases and folds in the orange gel helped break up the light a little creating a less lit look sympathetic to the fire inside the tent.

in-tent-mid-e1490981340247 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
A Stella 1000 with orange gel was used inside the tent to give the light from the fire a small boost.

It allowed me to increase the illumination in the tent, adding to the light from the fire without it being obvious that the tent interior was lit. For some of the shots I had an assistant sit in the tent, out of shot and slowly move the gel in front of the light to add a little movement to the light to mimic the firelight even better.

sihuette-e1490981444887 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
One particular shot on the storyboard was the silhouette of the drivers entering the tent. The Stella 1000 really helped punch trough the canvas sides of the tent.

At the moment I can’t show you the footage. That will have to wait until after the launch of the TV. But I’m really pleased with the way this scene came out. It’s challenging trying to shoot in the dark, in a blizzard, in temperatures well below freezing. Every aspect of getting this scene was hard. Opening a flight case to get out some kit meant getting snow on everything inside it. Just positioning the light up the woods was tough, the snow was up above my knees as I waded through it. Operating the camera is so much harder when it has a rain cover on it. The viewfinder was constantly misting up as snow fell on it non stop. Seeing the witness marks on the lens is difficult (although thankfully the marks on the Fujinon 20-120 are huge and easy to see).

20170317_205922-e1490981701785 Anatomy of a shot. Night Scene in Arctic Norway - Fujinon lenses, Stella Lights.
The Fujinon Cabrio XK6X20 lens all iced up at the end of the day. After shooting out in sub zero temperatures don’t take the camera inside until you are sure you have wrapped for the day!

But sometimes it’s challenges like these that make the job interesting. I know I was cursing and swearing at times trying to make these shots work, but seeing the scene come to life in the grade is all the more rewarding.

I’ll be writing more about the Fujinon 20-120 very soon, so why not subscribe to my blog using the subscribe bottom on the left.

Night Flyers. Shot with PMW-F3 in Singapore

I’m currently in Singapore staying at Clarke Quay. Most evenings a group of radio control kite flyers from a local store (goflykite.com) bring out their illuminated kites and fly them in the local park. It’s very pretty and seemed an interesting thing to try and shoot with my F3. As I’m travelling light, trying (and failing) to keep within a 20kg baggage allowance, I don’t have a tripod and I’ve only got a couple of lenses, my trusty 50mm Nikon f1.8 and my Tokina 28-70mm f2.6 zoom. Most of this was shot with the Nikon lens at +6db. I really wish I had a tripod and a longer lens! I did a little bit of grading work here and there to balance out the very orange street lights a little.