I’m going to be in the US at the end of December holding a number of 2 hour seminars and full day workshops. The 2 hour seminars are being sponsored by Sony and will give an overview of how to get the very best from the Sony PMW-F5 and PMW-F55 cameras.
As well as these seminars (which should be well worth attending) I am also running some in depth full day workshops on gamma, colorspace and log aimed at anyone that really wants to know how to get the very best from their cameras, whether that’s an FS5, FS7 or F5/F55. The S-Log Demystified workshops will in-depth and limited in numbers so plenty of time to answer any questions and help every attendee individually. I really believe these workshops will be interesting, informative and really help people get the very best from their cameras when shooting with S-log or even with other log gamma curves. Earlybird rates are available for the AbelCine workshops.
If you have a modern camera that can record log or raw and has 13 stops or more of dynamic range you need to stop thinking “video” and think “film”.
A big mistake most traditional video camera operators make with these big DR cameras is to treat them as they would a typical limited dynamic range video camera and constantly worry and obsess about protecting highlights. Why do we do this? Well probably because that’s what you do with cameras with a very limited range and that’s probably what you have had drummed into you for years. But now with modern large sensor cameras everything changes. When you get to a 14 stop range camera, even if you choose to shoot 2 stops over exposed (perhaps by using 500 EI on an FS7 or F5) you still have as much or more over exposure range as a conventional video camera and the highlight range that you do have is not subject to a knee or other similar acute highlight compression. So any highlights will contain a ton of high quality, usable picture information. By shooting over exposed by a controlled amount (1 to 2 stops), perhaps by using a low EI you gain very big improvements in the signal to noise ratio and get better saturated colors (opening the aperture lets more light onto the sensor, your colors will be better recorded). This allows you to pull a lot more information out of the data thin shadows and mid range. Most cameras that use log have very little data in the shadows. If you are recording with a 10 bit codec cameras that use variations of the Cineon log curve (Arri LogC, Sony S-Log3, Panasonic V-Log) only have about 80 luma shades covering the first 4 stops of exposure in total. Above the 4th stop the amount of data per stop increases rapidly so a little bit of deliberate over exposure really helps lift your darkest shadows up out of the noise and mire. Up in the highlights each stop has exactly the same amount of data, so over exposing a bit doesn’t compress the highlights as it would with a conventional camera, so a bit of mild over exposure is normally not noticeable.
Really with a 14 stop log camera you want to treat it like film, not video. Just like film, a 14 stop log camera will almost always benefit from a controlled amount of over exposure, highlights will rarely suffer or look bad just because you’re one stop hot, but he shadows and midtones will be significantly improved. And just like film, if you under expose log you will take a big hit. You will loose a lot of shadow information very quickly, have less color, it will be noisy and the highlight benefit will be marginal.
Looking forward to the KitPlus event in Manchester next Tuesday the 10th of November. I’ll be there to talk about large sensor cameras in general, the FS5 and to offer help and advice to those that visit including some guided tours around the Sony booth. Geoff Boyle will be giving lighting workshops. HaZ Dulall will be talking about budget VFX (his talks are fascinating). Plus of course there will be lots of kit on show from all the major players. http://www.kitplus.com/tour/
Want to know more about the FS5? check out my 2 hour seminar held at Vocas in the Netherlands. Primarily about the FS5 but from about 1 hour in I go into a lot of detail about gamma curves, log and exposure in general.
This is something that keeps coming up in my workshops. It’s very important if shooting with S-Log2 or S-Log3 not to under expose and in most cases it can be highly beneficial to over expose a bit. Especially if you are using a camera like the A7s or FS5 in 4K when you only have 8 bit data.
Take a look at this chart. It plots the S-Log2 and S-Log3 gamma curves on a log scale of f-stops against the amount of 10 bit or code values used to record each stop. The center line of the chart is middle grey. Both S-log2 and S-log3 provide 8 stops below middle grey and 6 stops above. Take a look at the darkest stop, the one that is -7 to -8 and look at how much data is allocated to that stop. With 10 bit recording you have according to this chart about 10 code values for S-Log2 and about 20 for S-Log3. That’s if you have 10 bit, and it’s not a lot of data. Admittedly there isn’t going to be a great deal of scene information in that darkest stop, deep in the shadows and the noise. But there’s part of the issue, the noise. If you have under exposed and you take this in to post and have to stretch out the shadows, the noise in these darkest shadows is going to look pretty coarse because it hasn’t been recorded with many shades/steps so stretching it out will make even “rougher” for want of a better term. If you are recording with 8 bit the problems is even worse. With 8 bit, S-Log2 will only have around 2 or 3 code values for that bottom stop, in effect the noise will have two values – black or +1 stop. Imagine how nasty that will look if you need to raise or stretch you blacks because you are under exposed, it will become very blocky and grainy.
The solution is to over expose a bit. By over exposing your footage by a stop when you go in to post production you will in most cases be bringing your levels down. So instead of stretching the noise out and making it worse you will be shrinking it down and reducing the negative impact it has on it’s image. Because cameras like the FS5, A7s etc have 14 stops of dynamic range this small bit of over exposure is going to make very little difference to your highlights in the vast majority of situations. Any slight over exposure you may have will likely look quite natural anyway, after all our own eyesight does also over expose, we don’t have unlimited dynamic range. On top of that the display technology does not exist to show a 14 stop range shot in it’s entirety and with natural contrast.
Northern Lights as seen on one of my Aurora Tours.
Don’t forget about my Northern Lights tours. I still have places for the 7th of Feb to 13th of Feb 2016. It’s always an incredible and unforgettable experience. A chance to find out how the Sami people live in up on the Finnmarksvidda in the arctic winter. As well as the Aurora or Northern Lights there’s snowmobiling, dog sled driving, ice fishing, camp fire cooking, traditional log fired sauna and so much more. Full details are here.
So finally, here it is! First seen at IBC over a year ago and eagerly awaited ever since, the Metabones Sony FZ to Canon EF lens adapter. This adapter fits the Sony PMW-F3, F5 and F55 cameras. It replaces the supplied PL mount with a very high quality, locking Canon EF mount that electronically controls the Canon lens aperture.
The adapter takes it’s power directly from the camera, to make it work correctly you need to go in to the camera menu and select the TypeA+12 or TypeC+12 lens adapter type. Once the menu has been set and the adapter fitted to the camera you will get a direct readout of the lenses aperture and focus distance in the viewfinder with the vast majority of electronically controlled Canon EF lenses.
Aperture ring and aperture scale on the Metabones FZ to EF adapter.
In addition on the adapter itself there is a large aperture ring and a window where the aperture number is clearly displayed. The aperture ring has a standard 0.8 pitch gear so you can remotely drive it with a follow focus motor if you need remote aperture control. One point to note is that the aperture ring indications go all the way down to f1. If your lens has a largest aperture of say f4, if you turn the ring past f4 the aperture will not magically open any wider than it can, so it is possible to have f2.8 or even f1 indicated in the window on the aperture ring while the lens may be at it’s actual maximum aperture. However don’t worry too much as if you look in the viewfinder the correct actual aperture of the lens is displayed. Also remember that if you are using an entirely mechanical lens such as a Samyang prime that the aperture control on the adapter will have no effect on the lens, you would use the aperture ring on the lens to adjust the aperture and you may not get the aperture and focus information in the viewfinder.
Lenses are secured by a locking ring on the Metabones FZ to EF adapter.
Mounting lenses on the adapter is easy. To attach a lens simply align the red dot on the lens with the red mark on the adapter and insert the lens into the lens mount. Then, instead of twisting the lens as you would do on a Canon camera you twist the large silver locking ring anti-clockwise and this clamps the lens very securely in place. This system ensures the lens is very secure so it won’t twist or wobble. This is very important if you’re using a lens with pitch gears and a follow focus as it stops the lens shifting against the force of the follow focus.
If your lens has image stabilisation then this will work so you can benefit from this when shooting on the move or with very long focal lengths.
The buttons and switches on the Metabones FZ to EF adapter.
On the side of the adapter there are two push buttons marked as FN1 and FN2. These currently appear to have no effect. The lens adapter firmware can be updated by the end user via a micro USB port, so perhaps in the future there will be extra functions for these buttons. Just above the buttons is a 3 way switch. This switches the adapter between manual, locked and auto. In manual the aperture ring controls the lenses aperture. Switch the switch to lock and the aperture is locked at the last set position. In Auto the camera controls the aperture automatically. For auto aperture the camera must be in Custom Mode and not using S-Log. Auto Exposure must also be turned on in the cameras menu. Once activated you can include an exposure offset via the camera menu to help deal with different lighting situations. It is worth remembering though that electronic Canon lens apertures operate in 1/8th of a stop steps. So any exposure changes mid shot will often be seen as small stepped brightness changes. Also in some situations you may find that the exposure the camera wants is right between two steps and in this instance the aperture will flicker between the two steps. This isn’t a fault or problem with the camera or the adapter, it’s just a characteristic of the way Canon EF lenses work and there’s nothing that Sony or Metabones can do about this.
Nice flocking inside the Metabones FZ to EF adapter.
The build quality is very good. The adapter is made mainly from aluminium alloy, machined to a very high standard and nicely anodised. The internal parts of the adapter are flocked with a high quality black flocking material that looks like it should be very good at reducing any internal reflections.
I really do think this is one of, if not the best FZ to EF adapter on the market. There are no wires or cables. Aperture is control by an aperture ring just as on a cine lens and you have an aperture indication right on the side of the adapter as well as focus distance and aperture indications in the viewfinder. The lens locks in to place securely and the build quality is excellent. So just on the features alone I would recommend this adapter, but then when you consider that it’s also the cheapest electronic FZ to EF adapter on the market it becomes a real no-brainer. If you need or want to use Canon EF lenses on your PMW-F5 or PMW-F55 then this adapter ticks all the right boxes.
NORTHERN LIGHTS 2016.
Don’t forget I run storm chasing and Northern Lights expeditions every year. I still have some places on the second Northern Lights tour in Feb 2016. These are amazing expeditions by snowmobile up on to the Finnmarksvidda. We go ice fishing, dog sledding, exploring, cook a meal in a tent and enjoy traditional Norwegian saunas.
One common question I am often asked is how to use Log or CineEI in low light situations. After all in the Sony CineEI mode or with a log camera such as the Alexa that use EI the actual recording gain is fixed, so often the recorded pictures are very dark. So what should you do?
My answer in many cases is simply not to use Log or EI. It’ really important to remember that the primary reason why log recording was developed was to make it possible to record a very large dynamic range using existing recording technologies. In order to do this lots of compromises are made. The main one being allocating less recording data to each stop of dynamic range. If you’re recording using 10 bit you typically have about 970 useable code values or shades. Use a gamma curve with 6 stop range and you have about 160 shades per stop, record using a log or other extended range gamma with a 14 stop range and you have just 70 shades per stop.
Lets think about a couple of different scenes for a moment. Scene one is a daytime scene that’s nice and bright with an 8 stop dynamic range. Scene 2 is a night time scene that is fairly dark and only has a 5 stop dynamic range. What happens if we shoot using log?
With the daytime scene things are pretty straight forward. You just expose as per the manufacturers recommendation. Assuming your camera is set to log and capable of a 14 stop dynamic range, if exposed at the base, recommended exposure levels you will be using a little under 60% of your available recording range, so a fair bit of data will be going to waste. But as the scene is bright you can always open up the aperture a bit and deliberately over expose by a stop or two so that now your using around 75% of the available data. You don’t normally want to over expose too much as grading becomes trickier, but at least when you have a bright scene you can open up the aperture to expand the recording range a bit to make better use of the data.
In low light however it get’s trickier as your aperture may already be wide open. In the second dark scene it’s quite possible that the 5 stops of light coming back from the scene aren’t bright enough to allow you to expose at the recommended levels. So instead of filling the zero to 5 stop recording range you might only be filling the zero to 4 stop range. Even if you can expose correctly with a 14 stop recording bucket like log you are only using a little over 35% of the available data and that’s a terrible waste. You won’t have much data to help you separate out any noise from the desired picture information in post production and because your recorded signal is small any compression noise will be relatively big in comparison to the picture information.
This is when it’s time to abandon log and go back to a conventional gamma curve. You don’t need log when the scene only has a limited dynamic range. If you use Rec-709, which has a 6 stop range (without any knee) instead of log, at the same ISO, then now instead of recording using only 35% of the available data you will be using almost 85% of the available data and that’s going to give you much more real picture information to work with in post production. You will get a much better end result by not using log.
If you need a bit more than a 6 stop range then there are plenty of other gamma curves to choose from that sit between 709 and log. Gamma curves such as Sony’s cinegammas or hypergammas which have dynamic ranges between 10 and 11 stops.
So remember, when you don’t need a 14 stop recording range, then consider using an alternate gamma curve. It’s not just in low light but also in other controlled lighting situations such as green screen work.
Want to win a PXW-FS5 or A7s? Sony are running a free to enter worldwide competition to win a PXW-FS5. All you have to do is create a 2 min short film with the theme “No More Limits” upload it to YouTube and enter via the entry form by 31st October. The videos which receive the most YouTube ‘likes’ from the 1st-15th November will form regional shortlists, an Independent expert from each region will select their favourite. These regional finalists will each win a Sony A7S (or equivalent), and will be entered into the global final to win the PXW-FS5. The global winner and regional winners will be announced during a webinar on 17th December. Click here for the full details.