So here are the top 5 Things you have to think about when shooting in High Speed Rate mode.
1 – Natural Light vs Artificial Light.
As a Cinematographer I understand the importance of Light for a film but when you shoot in a High Speed Rate mode you have to think differently. Although the RED EPIC MX sensor has a base sensitivity of 800 ISO (by comparison your Canon 5D has a base sensitivity of 320 ISO) you will need a tremendous amount of equipment in order to create your own light (think 10 to 40 Kw). For that you will need a lighting truck and an army of electricians to set up all the huge lights you will have on set. Not ideal for a low budget film.
There is two simple equations to give you rough calculation of how much light you’ll need.
X (special frame rate) divided by Y (natural frame rate – 25 fps) = Z (how many times more light you need)
So In our case: X (200) divided by Y (25) = Z (8)
You’ll need roughly eight times as much light as you would shooting at 25 fps.
Also worth knowing is that every time you double the frame rate you have to go up one f-stop.
So 25 fps to 50 fps equals 1f-stop up , 50 to 100 equals 2 f-stops up, 100 to 200 equals 3 etc.
So your aperture will be 3 stops more open at 200 fps than at 25 for the same shot. Still with me? Basically, if you shot with a 25mm lens at f8 to get the same result at 200 fps you’ll need to be at f2.8.
Cyril wanted to shoot outside and the sun provided me with a gigantic amount of light for free. Lucky me! But the sun doesn’t wait. And there is my problem. I had to be really careful with the light axis, otherwise I’d have mismatches in the light. So I had to be careful about the location. Always an issue when shooting but especially on this kind of low budget, natural light shoot: it’s the same has buying a house. What are the the most important things? Location, Location, Location.
Where does the Sun rise? Where does it set? How many hours of sunlight will I have? What time of the day are we going to shoot? How will the light axis change? At 200 fps I can’t even think of using a reflector; if it works well at 25 fps it will be useless at 200.
Now I have a better idea because I’m familiar with the two protagonists on set: The Sun and the Camera. Regarding the latter, the RED is naturally calibrated at 800 ISO at 25 fps. So at 200 fps it will be around 100 ISO which is perfect for shooting outside under a slightly cloudy sky but it’s a little too much (for my taste) to shoot in bright sunlight. However is always better to have too much than too little. It also means I’ll have to work with high f-stops but it will help my Focus Puller (FP) by giving him a greater depth of field, making his life a little easier for the tracking shot and other camera movements.
2 – The crop Factor of shooting in 3K WS mode.
The RED EPIC MX has a 5K sensor but when you want to shoot at a higher frame rate the number of pixels will decrease as the frame rate increases. You can see that in the RED EPIC User manual. Also with our settings we have a 3.5 X multiplier for the lenses ( an 18 mm becomes roughly a 50 mm)
We chose to shoot at an aspect ratio of 2.40 ratio (what RED calls WIDE SCREEN) therefore we had a more beautiful, more cinematographic look. We had to be really precise with our lenses because of the ratio and the definition of the sensor. We had a cropped image, larger than 1.77, but not as high.
During the test shots, I asked my team to take precise measurements with each lens. For the wide shot and with the 18 mm lens the subject had to be at 5,80 m (19 ft) from the camera and more than 20m (65 Ft) for the 85mm from the camera.
I knew Cyril would want a lot of establishing shots so, with that in mind, it was not difficult to calculate the distance we had to be from the subject to get a nice shot. Also with this parameter, communication would be easier with the location manager and the first assistant director about my organisational needs.
The tricky bits were the movements, as most of the shots were tracking shots but without a big dolly. We used a pretty homemade system and it became really difficult for the FP to stay in focus as we increased the focal length.
That’s why I had to consider each parameter individually, in order to work with them all. For example, if I needed to I could remove a Neutral Density filter from the matte box in order to close the diaphragm a little but still (thank you 3K sensor!) maintain a beautiful depth of field in my shot.
3- Shutter Speed
In the process of setting up the camera each setting play its role. But there is one I haven’t mentioned until now. Shutter Speed.
The default setting on the RED is 23,98 fps time base so don’t forget to change it to 25 or you’ll have trouble with the shutter speed and in post production, especially if you’re used to working at 25 fps time base.
When you shoot at 25 fps the shutter speed is 1/50, but when you change the frame rate to 200 fps the RED automatically sets the shutter at 1/200. That could work but I prefer to double up 1/400 in order get ride of the blurring caused by camera movement or camera shake. In addition, it gives me a more precise focus point and an image with more peaking and detail as well as compensating for any faults which might appear due to the focal length. When you shoot at this frame rate, you cannot be out of focus.
These settings continue to make the camera less sensitive. So it allows me to compensate by re- opening the diaphragm a little. It re-establishes some depth of field in the shot (so that not everything is in focus, even with the 18 mm). It also allows me to take pity on my FP (not that he needs it) but it’s a team effort after all! Which is how we were able to pull off a tracking shot using an 85mm lense on a homemade dolly.
So, now we have a camera that is almost ready to go. The camera is set up, the production schedule is taking shape but there is something I really have to think through before shooting. It’s more about post-production than actual production.
4- Compression and Data Factor
One thing to bear in mind when considering shooting on a RED (EPIC, DRAGON, SCARLET…) is that RED Inc has a policy of proprietory equipment and software. Everything and I mean everything is designed by RED for RED. Even the format you shoot on. REDCODE and the file extensions .R3D are designed by and for RED. In order to see your rushes on your laptop, you have to download a program called RED CINE-X PRO (Don’t worry it’s free).
Fortunately, all the information you need is available on the RED website (you will need it in post production). Another plus is that REDCODE works in Adobe Premiere Pro or Avid without the need to purchase any other plug ins.
REDCODE also changes the way your calculate the disk space you’ll need when you transfer from the REDMAG to your hard-drive. One thing I found astonishing: you have a choice of compression ratios. When you shoot at 200 fps you have to think about compression, of course your natural instinct is to shoot at the lowest possible compression ratio but don’t forget how much Data you will have to back up.
With REDCODE you can choose a compression ratio from 3:1 to 18:1. But, as you will notice in your test shot, when you change the frame rate the camera prevents you from using some compression ratios. So, with my settings, my maximum compression ratio is 7:1. So, in this respect, the compression ratio becomes another parameter. You have to consider the compression with regard to the type of film you are shooting (Internet, Digital Cinema, Short film, Commercial etc, etc) as well as the conditions on set e.g If you are shooting outside with only one REDMAG and if your film is for the Internet or Smartphone maybe a 5:1 compression ratio is not what you are looking for. Maybe in that case a 10:1 ratio would be more appropriate.
Now you have all of your most important settings, you’re ready to shoot. For those of you who have used the RED ONE you’ll discover something quite amazing! Remember How the RED ONE created auxiliary file for each shot alongside the .R3D? (Full Quality Shot, Half Quality, Low Quality and finally a Proxy shot for editing). It was a great idea as it allowed you to watch your shot on any kind of player. The down side was that you ended up yourself with gigantic (even apocalyptic, I should say) amounts of data on your hard drive and you had to face hours and hours of copying to back up.
Now you only have a .R3D file and when you open it in RED CINE-X PRO you just have an other .RPM file which contains all your settings because the camera considers your setting as meta- data even the ISO, and REDCINE allows you to change everything (which may not sound like much but in practice is truly magical! ).
All this put together means that you don’t have a hard drive melting amount of data, even if you shoot at 5K with a compression ratio of 1:1.
So you can say so long to hours spent in front of your computer waiting for it to finish backing up (Don’t fool yourself although it will take plenty times all the same).
5- On set: The trouble with not seeing what you shooting.
Now we have everything ready! We are on set! It’s D-Day and now comes tricky part of shooting at 200 fps. You won’t be able to see what you shoot while you are shooting it. Each time you will have to replay it and of course you will notice faults you didn’t see at 25 fps.
Shooting in slow motion makes everything look gorgeous, even the simple action of running. The faults which go with it looks gorgeous as well. For example, an action that takes 5 sec will last more than a minute and half at 200 fps. That’s why you really need to work with the first assistant director on the production schedule. You need a more relaxed schedule than usual because you have to set up your shot, make some minor settings adjustments, do a test shot, replay it, make some more adjustments, shoot some takes and finally check the last two takes to be sure you have a good one.
Usually, you have time to see what you as you shoot but in this case everything has to be faster: camera movement, actors performance, special effects etc So it’s not about what you see, it’s more about whether you feel it or not. One very cool thing though is, you have to ask each member of your crew, if they felt it too! So it creates a good team spirit, a real cohesion on set and also a good work rhythm.
As you don’t have time to playback each take, you have to playback the good one, just to be sure. Of course your director will have the final say but be prepared to discover some minor faults in post- production even if you were sure on set that your favorite take was the good one.
Shooting on a RED is a challenge because you have to adapt yourself to the camera (and not the other way around) and learn to speak its language. In addition, you have to answer many questions before you even do your test shots. It’s the kind of camera that requires you to be prepared, do you homework. And therein lies the challenge because as I said you have to think differently. It ’s also a real pleasure because the results will probably blow your mind and shooting at 200 fps gets everyone on set involved in a way that creates a really good team bond.
Finally, shooting at 200 fps will challenge you and your knowledge on many levels but it will be a good experience and something that will help you progress in your craft. Personally, I’m looking forward to getting my hands on a Phantom FLEX which can shoot 2875 fps. So if you know anyone who has one, drop me a line…