Although I wouldn’t normally recommend removing the screws from Sony cameras there are times when this is something you need to do, for example to remove the microphone mount on an FX6.
Most of the small screws have a thread locking compound applied to the threads to prevent them from shaking or vibrating loose. This can make them hard to unscrew.
JIS NOT Phillips!!
The main issue is that most cross of the commonly found small and miniature head screw drivers are manufactured to the “Philips” standard. But the screws used on the Sony cameras are manufactured to the JIS standard. The differences between these two very similar looking standards means that you will not get a secure and tight fit between a Philips screw driver and a JIS screw head. The edges of a Philips screwdriver are at an angle that is too shallow to properly engage with the full depth of a JIS screw head. So when you try to undo a tight screw the head of the screw will deform or strip, often to the point where it can’t be undone.
Whenever working on Sony cameras you should use JIS standard screwdrivers and ensure the screwdriver is the correct size for the screws you are working with. The smaller screws used for thing like the microphone mount on the FX and Alpha series cameras are JIS size +0 or +00. A JIS size +0 seems to fit most but I would also get a +00.
Don’t try to use a miniature Philips screwdriver on a tight JIS screw. It might look like it fits, but only a very small part of the screwdriver head will be correctly engaged with the JIS screw and once the screw head is damaged you can’t undo the damage and it may become impossible to remove the screw without drilling it out.
If you search for “Vessel JIS” you should be able to find good quality small and miniature JIS screwdrivers on Amazon, ebay or from other suppliers.
Category Archives: FX6
Don’t Attach Extension Arms To the Side Of an FX6.
I attempts to turn the FX6 into a shoulder camera I am seeing a lot of people removing the FX6’s handgrip from the side of the camera and then attaching an extension arm to the camera body where the hand grip normally attaches, perhaps either directly with a dedicated arm or by fitting a rosette to the camera body.
I strongly recommend you do not do this!
A long arm increases the amount of force that can be applied to the body of the camera and it wasn’t designed to take the forces an arm places on it. Especially if the camera is loaded up with other accessories such as monitors, V-Lock adapters or a base plate. There have been several instances of the camera body fracturing around the hand grip mount when an extension arm has been used. Replacing the camera body is not cheap and it is unlikely to be covered under any warranty as it wasn’t designed to be used this way.
Instead mount the arm to a base plate, there are many FX6 base plates that include a suitable rosette for arms and other accessories.
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.
Chart of Sony Dual ISO Base Levels
Here’s a handy chart of the base ISO levels for Sony’s cinema line cameras including Venice, the FX9, FX6, FX3 and FX30 as well as the A7SIII and A7IV. The new Sony FR7 is the same as the FX6. I’ve include the base ISO’s for both S-Log3 and S-Cinetone. If you use other gammas the base levels may be different to the S-Cinetone base level, so these values should only be used for S-Cinetone and S-Log3. You can click on the image for a bigger version or left click on it to download it.
As explained above there is a difference in the way the dual ISO functions work between the FX6/FX3/A7SIII and the other cameras. Venice, the FX9 and FX30 have sensors with two distinctly different sensitivities. These cameras offer near identical performance at either the low or high base ISO. Sony call these cameras “Dual Base ISO” as in most cases the two base ISO’s can be used in exactly the same way depending on which best suits the light level you are working at and a near identical image produced.
The other cameras (FX6, FX3, A7SIII) probably have a dual gain sensor plus additional processing to deliver their 2 distinctly different sensitivity ranges. The result is that there is a more visible increase in noise at the high range (compared to the Dual Base ISO cameras) plus a very slight reduction in dynamic range. However, the noise level in the high base setting is significantly lower than you would have by adding gain to get to the same level and the upper base sensitivities are very usable and allow for shooting at very low light levels.
For more information on Dual Base ISO sensors take a look here: https://www.xdcam-user.com/2019/11/what-is-dual-base-iso-and-why-is-it-important/
Sony’s FR7, an FX6 that can pan and tilt.
I first came across the new Sony FR7 PTZ camera (Pan, Tilt and Zoom) at IBC in Amsterdam in September and at first I was a little confused by it. PTZ cameras are not new and this is a fairly big unit, so who would actually want one and what would they use it for, especially given the shorter zoom ranges possible because of the use of a large sensor. But now I am convinced that the FR7 will be a big hit – what’s changed my mind?
For those that haven’t seen it yet the FR7 is in essence a Sony FX6 camera that has been adapted and modified to fit in a remotely controlled pan and tilt head. You really do get all of the FX6’s features and performance including onboard recording to SD and CFExpress type A cards, S-Cinetone, S-Log3 and CineEI, raw output, built in variable ND filter and Sony great autofocus etc etc. But in a form factor that allows you to operate the camera remotely via either an optional control panel with a joystick or via any device with a web browser.
Remote PTZ (Pan, Tilt, Zoom) cameras get used a lot in shows like Big Brother, Love Island, First Date etc but until now, generally the image quality hasn’t been as good as most mainstream broadcast cameras. This means that when you cut between the PTZ camera and other main cameras the difference is often quite obvious. So, straight away there is the obvious use of the FR7 for these types of shows, so that the image quality will be as good as any of the other cameras being used. It may mean that more PTZ cameras will be used as quality is no longer going to be an issue.
Wildlife.
PTZ cameras also get used a lot in wildlife productions. A PTZ camera can be placed close to an animals nest or placed closer to a feeding area without disturbing the animals natural behaviour as a camera operator might. PTZ cameras can be used to film animals that may be dangerous to a camera operator or left somewhere remote for days, weeks or even months on end. Again, often the quality of these cameras is noticably different to the main cameras used and more often than not the small sensors in most PTZ cameras don’t do well in low light. The ability to use the FR7’s high sensitivity mode and shoot S-Log3 at 12,800 ISO with a fast lens will really open up a lot of new possibilities for wildlife film makers. Because you can fit just about any reasonably sized lens to the FR7 it opens up the possibility of fitting one with an image intensifier for extreme low light work. In addition the built in variable ND filter will be a great help for wildlife film makers working in variable and changing lighting conditions. The FR7 is controlled over an ethernet connection, so with a simple 4G router and a connection to the internet the camera could be controlled from the comfort of a warm studio anywhere in the world.
But what about other applications? Would a freelance camera operator like me benefit from one? Well I think the answer may be yes.
The Ultimate “B” Camera?
For 2 camera shoots such as interviews the FR7 can be used as a second camera and you have the ability to control it from the main camera position. This would be so much easier than having to walk over to the second camera to make a simple adjustment or reframe it. Instead of being a simple locked off shot that never ever changes your B camera can be moved and adjusted more frequently to add more variety to your shots. Program in some preset positions and you can confidently reframe your shot at the single press of a button. Creating presets is quick and easy.
Placing it where you can’t normally put a camera.
And what about getting shots from places or angles that aren’t normally possible? If you shoot conferences, events or performances, being able to place the camera on the front of the stage or in front of the podium opens up a lot of new possibilities. The FR7 won’t obstruct the audiences view in the same way that a camera on a tripod with an operator will and it’s far less distracting. I’m going to be shooting some live performances with one very soon and it will allow me to get the camera into locations around the performances where you just can’t normally get a shot. You can hang it from a ceiling or a lighting truss for overhead shots. You can even mount it on a jib. Once you start thinking about all the places you can place one, places that are unsafe for a camera operator or just simply inaccessible it does start to become an interesting proposition.
Time-lapse and trick shots.
You can also use it for time-lapse or other shots where you need to repeat the same move over and over. By setting up preset positions for the start and end points and then adjusting the speed of the move you can perform extremely slow moves all the way to very fast moves from point to point and each time the move is the same. Like the FX6 the FR7 has a built in intervalometer (interval record), so shooting time-lapse is easy. You can also make it speed ramp the moves if you need to.
The big deal about the FR7 is that while PTZ cameras are not new, they have never offered the image performance possible from a large sensor camera. Because the images from the FR7 closely match the rest of the Sony cinema line it opens up more possible uses. And the cost isn’t prohibitive, it’s not that much more than a normal FX6. Its limiting factor is the range of power zoom lenses that are currently available. The 28-135mm power zoom will be the lens that most will use with it and while this is going to be very useable for many things it isn’t a vast zoom range compared to the zooms typically fitted to PTZ cameras with very small sensors. You can use the cameras clear image zoom function to extend the zoom range by up to 1.5x in 4K if you need to. If you need a longer focal lengths then I believe it is possible to use the Sony 70-200mm with the 2x extender, but this isn’t a power zoom. Hopefully we will see more E-Mount power zoom lenses coming in the future for this very interesting camera.
Come back in about a month to find out how I get on shooting a live performance with the FR7. I’m really looking forward to putting it through its paces as I’m strongly considering getting one for myself – thinks – Northern Lights remotely controlled from home??????
Sony FX6 Intermittent Audio – Is Your Handle Secure?
There have been a few people popping up on various user groups and forums complaining of a sudden loss of audio or intermittent audio on their Sony FX6 cameras. A common cause of the loss of audio on the FX6 is a slightly loose top handle. The XLR inputs, MI Shoe and the cameras built in microphones are all part of the top handle, so if the handle is a little loose and the connection between the camera and handle isn’t perfect you can suddenly lose all your audio inputs.
As the connection between the handle and camera is a digital one you often won’t get any warning and if you are not wearing headphones you might not notice that you no longer have audio. Hint – wear headphones and monitor your audio when doing anything where the audio is even the slightest bit important 😉
So it is advisable to regularly check that the thumb screws that secure the handle are tight as if done up finger tight they do have a tendency to work lose over time. The thumbscrews have sockets for an allen key and I strongly suggest you use an allen key to tighten them up, done up this way they rarely come loose.
FX6 Fan Noise and Fan Modes.
Cooling fans (or perhaps more accurately temperature regulating fans) are an unfortunate necessity on modern high resolution cameras. As we try to read more and more pixels, process them and then encode them at ever greater resolutions more and more heat is generated. Throw in higher frame rates and the need to do that processing even faster and heat becomes an issue, especially in smaller camera bodies. So forced air cooling becomes necessary if you wish to shoot uninterrupted for extended periods..
Many camcorder users complain about fan noise. Not just with the FX6 but with many modern cameras. But fans are something we need, so we need to learn to live with the noise they make. And the fan isn’t just cooling the electronics, it is carefully regulating the temperature of the camera trying to keep it within a narrow temperature range.
The fan regulates the temperature of the sensor by taking warm air from the processing electronics and passing it over fins attached to the back of the sensor. I am led to believe that at start up the fan runs for around 30 seconds to quickly warm up the sensor. From there the camera tries to hold the sensor and electronics at a constant warm temperature, not too cold, not too hot, so that the sensor noise levels and black levels remain constant. The sensor is calibrated for this slightly warm temperature.
As well as running in the default auto mode there are “minimum” and “off in record” modes for the fan in the technical section of the FX6’s main menu. Minimum forces the fan to run all the time at a low level so it doesn’t cycle on and off, possibly at higher levels. Off in record turns the fan off when recording – however the fan will still come on if there is a risk of damage due to overheating. Off in record can result in minor changes to noise as black levels during longer takes as the camera’s internal temperature rises, but you’ll likely only see this if you look carefully for it.
Using Auto Exposure With Cine EI.
First – What is “Exposure”
Something I find useful to consider is that “Exposure” is the amount of light that you put onto the sensor or film stock in your camera. It isn’t brightness, it is how much light. If you think about it, if you use a light meter to find you exposure settings, the light meter has no idea how bright the pictures will be, all it does is give you the shutter and aperture values needed to put the correct amount of light onto the sensor or film stock.
How Cine EI Works.
Next we need to think about how Cine EI works. You have to remember that when shooting using Cine EI the only thing that changes when you change the EI value is the brightness of the LUT and it is also worth considering that different LUTs may be completely different brightness. There is no change to the sensitivity of the sensor and no direct change to the brightness of what is recorded. To change the brightness of what is recorded YOU must change the aperture, shutter speed or ND etc. Normally you would monitor your images via a LUT and then you must adjust the exposure so the image on the viewfinder looks correct at the new Exposure Index, or use the waveform to measure the LUT and use this to set the exposure for the new EI. And by changing the exposure you are adding an exposure offset putting more (or less) light on to the sensor than would be normal at the base EI.
AE In Cine EI.
If you wish to use auto exposure in the Cine EI mode then you need to understand that the camera’s auto exposure system measures what is being recorded. It does not measure the LUT levels. The auto exposure system is unaware of your desire to expose the sensor more or less brightly than normal and will always base the exposure on the base ISO, not the Exposure Index. As a result if you are using AE and you go from 800 EI to 400 EI the image seen via the internal LUT will get darker by one stop, the AE will NOT compensate for the lower EI. If you were to manually brighten the exposure by one stop the cameras exposure meter will think you are now over exposed – because you are!
Adding Offsets.
The only way around this is to add an offset to the AE system to account for the offset added by the different Exposure Index. For example if you want to shoot at 400EI (The LUT becoming 1 stop DARKER) then you would need to add a +1.0 stop offset to the cameras AE settings to offset the exposure 1 stop brighter. Each time you halve the EI you should add an extra +1 stop of offset. Each time you double the EI you should include an extra -1 stop offset.
There are a couple of ways to do this but the quickest is to use the Quick Menu function that is by default assigned to button 5 on the hand grip or button 8 on the handle. Press the direct menu button and then use the thumbstick to go the AE+0 indication just above the shutter speed indicator and add your offset.
Or you can long press the menu button to go into the cameras main menu then go to the – Shooting – Auto Exposure page and add your offset to the Level setting.
I don’t recommend the use of Auto Exposure in Cine EI. For a start AE uses the average brightness of the scene to set the exposure level, often this isn’t appropriate for Log. When shooting with log generally you want to ensure that it is your mid range is exposed at the right level and you don’t want bright highlights to result in an under exposed mid range. Additionally if the exposure changes mid shot this can make grading very difficult. If you do use auto exposure in Cine EI, then as well as adding any necessary offsets I also recommend slowing down the responsiveness of the AE using the “Speed” setting in the Auto Exposure menu. Using a value such as -60 will slow down the rate at which the AE will change the exposure which helps avoid rapid auto exposure changes for momentary light changes within the scene.
It is really important to remember that Exposure is NOT brightness. Exposure is how much light you put on the sensor. A light meter doesn’t know how bright you want your pictures to be. All it knows is the correct amount of light to put on to the sensor for the “correct” exposure. If using an external light meter provided you put the right values into your light meter it will give you the correct exposure settings, even though it has no idea how bright your pictures will be and the camera’s internal exposure meter acts in a similar way, so offsets are needed to match each EI you use.
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CineEI is not the same as conventional shooting.
CineEI is different to conventional Shooting and you will need to think differently.
Shooting using CineEI is a very different process to conventional shooting. The first thing to understand about CineEI and Log is that the number one objective is to get the best possible image quality with the greatest possible dynamic range and this can only be achieved by recording at the cameras base sensitivity. If you add in camera gain you add noise and reduce the dynamic range that can be recorded, so ideally you always need to record at the cameras base sensitivity for the best possible captured image.
Sony call their system CineEI. On an Arri camera the only way to shoot log or raw is using Exposure Indexes and it’s the same with Red, Canon and almost every other digital cinema camera when shooting log. You always record at the cameras base sensitivity because this will deliver the greatest dynamic range.
Post Production.
A key part of any log workflow is the post production. Without a really good post production workflow you will never see the best possible results from shooting Log. An important part of the post production workflow will be correcting for any exposure offsets used when shooting. If something has been exposed very brightly, then in post you will bring that exposure down to a normal level. Bringing the levels down in post will decrease noise. The flip side to this is that if the exposure is very dark then you will need to raise the levels in post and this will make then more noisy
Exposure and Light Levels.
It is assumed that when using CineEI and shooting with log that you will control the light levels in your shots and use levels suitable for the recording ISO (base ISO) of the camera using combinations of aperture, ND and shutter speed, again it’s all about getting the best possible image quality. If lighting a scene you will light for the base ISO of the camera you are using.
Here’s the bit that’s different:
Changing the EI (Exposure Index) allows you to tailor where the middle of your exposure range is. It allows you to alter the balance between more highlight range with less shadows or less highlight range with more shadow information in the captured image. On a bright high contrast exterior you might want more highlight range, while for a dark moody night scene you might want more shadow range. Exposing brighter puts more light on to the sensor. More light on the sensor will extend the shadow range but decrease the highlight range. Exposing darker will decrease the shadow range but also allow brighter highlights to be captured without clipping.
IMPORTANT: EI is NOT the same as ISO.
ISO is a measure of a film stock or camera sensors SENSITIVITY to light. It is the measure of how strongly the cameras sensor responds to light.
Exposure Index is a camera setting that determines how bright the image will become for a given EXPOSURE. While it is related to sensitivity it is NOT the same thing and should always be kept distinct from sensitivity.
ISO= Sensitivity and a measure of the sensors response to light.
EI = Exposure Index – how bright the image seen in the viewfinder will be.
The important bit to understand is that EI is an exposure rating, not a sensitivity rating. The EI is the number you would put into a light meter for the optimum EXPOSURE for the type of scene you are shooting. The EI that you use depends on your desired shadow and highlight ranges as well as how much noise you feel is acceptable.
What Actually happens when I change the EI value on a Sony camera?
On a Sony camera the only things that change when you alter the EI value are the brightness of any Look Up Tables (LUTs) being used, the EI value indicated in the viewfinder and the EI value recorded in the metadata that is attached to your clip.
Importantly – To actually see a change in the viewfinder image or the image on an external monitor you must be viewing your images via a LUT as the EI changes the LUT brightness, changing the EI does not on it’s own change the way the S-Log3 is recorded or the sensitivity of the camera. If you are not viewing via a LUT you won’t see any changes when you change the EI values, so for CineEI to work, you must be monitoring via a LUT.
Raising and Lowering the EI value:
When you raise the EI value the LUT will become brighter. When you lower the EI value the LUT will become darker.
If we were to take a camera with a base ISO of 800 then a nominal “normal” exposure would result from using 800 EI. When the base ISO value and the EI value are matched, then we can expect to get a “normal” exposure.
Let’s now look at what happens when we use EI values higher or lower than the base ISO value.
(Note: One extra stop of exposure is the equivalent of doubling the ISO or EI. One less stop of exposure is the equivalent of halving the ISO or EI. So if double 800 EI so you get to 1600 EI this would be considered 1 stop higher. If you double 1600 EI so you are at 3200 EI this is one further stop higher. So 800 EI to 3200 EI is 2 stops higher)
If you were to use a higher EI, let’s say 3200 EI, two stops higher than the base 800 EI, then the LUT will become 2 stops brighter.
If you were using a light meter you would enter 3200 into the light meter.
When looking at this now 2 stops brighter viewfinder image you would be inclined to close the aperture by 2 stops (or add ND/shorter shutter) to bring the brightness of the viewfinder image back to normal. The light meter would also recommend an exposure that is 2 stops darker.
Because the recording sensitivity or base ISO remains the same no matter what the EI, the fact that you have reduced your exposure by 2 stops means that the sensor is now receiving 2 stops less light, however the recording sensitivity has not changed.
Shooting like this, using a higher EI than the base ISO will result in less light hitting the sensor which will result in images with less shadow range and more noise but at the same time a greater highlight range.
A very important thing to consider here is that this is not what you normally want when shooting darker scenes, you normally want less noise, more shadow range. So with CineEI, you would normally try to shoot a darker, moody scene with an EI lower than the base ISO.
This goes completely against most peoples conventional exposure thinking.
For a darker scene or a scene with large shadow areas you actually want to use a low EI value. So if the base ISO is 800 then you might want to consider using 400 EI. 400 EI will make the LUT 1 stop darker. Enter 400 EI into a light meter and compared to 800 the light meter will recommend an exposure that is 1 stop brighter. When seeing an image in the viewfinder that is 1 stop darker you will be inclined to open the aperture or reduce the ND to bring the brightness back to a normal level.
This now brighter exposure means you are putting more light on to the sensor, more light on the sensor means less noise in the final image and an increased shadow range. But, that comes at the loss of some of the highlight range.
Need to think differently.
The CineEI mode and log are not the same as conventional “what you see is what you get” shooting methods. CineEI requires a completely different approach if you really want to achieve the best possible results.
If you find the images are too dark when the EI value matches the recording base ISO, then you need to open the aperture, add light or use a faster lens. Raising the EI to compensate for a dark scene is likely to create more problems than it will fix. It might brighten the image in the viewfinder, making you think all is OK, but on your small viewfinder screen you won’t see the extra noise and grain that will be in the final images once you have raised your levels in post production. Using a higher EI and not paying attention could result in you stopping down a touch to protect some blown out highlight or to tweak the exposure when this is probably the last thing you actually want to do.
I’ve lost count of the number of times I have seen people cranking up the EI to a high value thinking this is how you should shoot a darker scene only to discover they can’t then make it look good in post production. The CineEI mode on these cameras is deliberately kept separate from the conventional “custom” or “SDR” mode to help people understand that this is something different. And it really does need to be treated differently and you really do need to re-learn how you think about exposure.
For dark scenes you almost never want to use an EI value higher than the base ISO value and often it is better it use a lower EI value as this will help ensure you expose any shadow areas sufficiently brightly.
The CineEI mode in some regards emulates how you would shoot with a film camera. You have a single film stock with a fixed sensitivity (the base ISO). Then you have the option to expose that stock brighter (using a lower EI) for less grain, more shadow detail, less highlight range or expose darker (using a higher EI) more grain, less shadow detail, more highlight range. Just as you would do with a film camera.
Sony’s CineEI mode is not significantly different from the way you shoot log or raw with an Arri camera. Nor is it significantly different to how you shoot raw on a Red camera – the camera shoots at a fixed sensitivity and any changes to the ISO value you make in camera are only actually changing the monitoring brightness and the clips metadata.
Exposing more brightly on purpose to achieve a better end result is not “over exposure”. It is simply brighter exposure. Over exposure is generally considered to be a mistake or undesirable, but exposing more brightly on purpose is not a mistake.
Should You Use In Camera Noise Reduction Or Not?
This is another common question on many user groups. It comes up time and time again. But really there is no one clear cut answer. In a perfect world we would never need to add any noise reduction, but we don’t live and shoot in a perfect world. Often a camera might be a little noisy or you may be shooting with a lot less light than you would really like, so in camera NR might need to be considered.
You need to consider carefully whether you should use in camera NR or not. There will be some cases where you want in camera NR and other times when you don’t.
Post Production NR.
An important consideration is that adding post production NR on top of in-camera NR is never the best route to go down. NR on top of NR will often produce ugly blocky artefacts. If you ever want to add NR in post production it is almost always better not to also add in camera NR. Post production NR has many advantages as you can more precisely control the type and amount you add depending on what the shot needs. When using proper grading software such as DaVinci Resolve you can use power windows or masks to only add NR to the parts of the image that need it.
Before someone else points it out I will add here that it is almost always impossible to turn off all in camera NR. There will almost certainly be some NR added at the sensor that you can not turn off. In addition most recording codecs will apply some noise reduction to avoid wasting data recording the noise, again this can’t be turned off. Generally higher bit rate, less compressed codecs apply less NR. What I am talking about here is the additional NR that can be set to differing levels within the cameras settings that is in addition to the NR that occurs at the sensor or in the codec.
Almost every NR process, as well as reducing the visibility of noise will introduce other image artefacts. Most NR process work by taking an average value for groups of pixels or an average value for the same pixel over a number of frames. This averaging tends to not only reduce the noise but also reduce fine details and textures. Faces and skin tones may appear smoothed and unnatural if excessively noise reduced. Smooth surfaces such as walls or the sky may get broken up into subtle bands or steps. Sometimes these artefacts won’t be seen in the cameras viewfinder or on a small screen and only become apparent on a bigger TV or monitor. Often the banding artefacts seen on walls etc are a result of excessive NR rather than a poor codec etc (although the two are often related as a weak codec may have to add a lot of NR to a noisy shot keep the bit rate down).
If you are shooting log then any minor artefacts in the log footage from in camera noise reduction may be magnified when you start grading and boosting the contrast. So, generally speaking when shooting log it is always best to avoid adding in camera NR. The easiest way to avoid noise when shooting with log is to expose a bit brighter so that in the grade you are never adding gain. Take gain away in post production to compensate for a brighter exposure and you take away much of the noise – without giving up those fine textures and details that make skin tones look great. If shooting log, really the only reason an image will be noisy is because it hasn’t been exposed bright enough. Even scenes that are meant to look dark need to be exposed well. Scenes with large dark areas need good contrast between at least some brighter parts so that the dark areas appear to be very dark compared to the bright highlights. Without any highlights it’s always tempting to bring up the shadows to give some point of reference. Add a highlight such as a light fixture or a lit face or object and there is no need to then bring up the shadows, they can remain dark, contrast is king when it comes to dark and night scenes.
If, however you are shooting for “direct to air” or content that won’t be graded and needs to look as good as possible directly from the camera then a small amount of in camera NR can be beneficial. But you should test the cameras different levels to see how much difference each level makes while also observing what happens to subtle textures and fine details. There is no free lunch here. The more NR you use the more fine details and textures you will lose and generally the difference in the amount of noise that is removed between the mid and high setting is quite small. Personally I tend to avoid using high and stick to low or medium levels. As always good exposure is the best way to avoid noise. Keep your gain and ISO levels low, add light if necessary or use a faster lens, this is much more effective than cranking up the NR.