In this video you’ll learn about the important role shutter speed plays in not only correctly
exposing your shot, but also in achieving the much sought after ‘film look’ on a
mobile device through its impact on motion blur, and how you can set this manually using
FiLMiC Pro with the Moondog Labs Filter Kit for pretty incredible results.
If you’re an iPhone filmmaker you've probably already heard of Moondog Labs as they make
the anamorphic lens that was used to shoot the award winning iPhone 5s shot feature film
Tangerine, and now they make a range of premium quality neutral density and polariser filters
that they were kind enough to send out for testing.
I received the 52mm Filter Mount for the Moondog anamorphic lens, which is fitted by loosening
the screw, sliding it over the lens, and tightening to secure.
As it comes with a lens cap, you can leave it on permanently which is a nice touch.
But you don’t have to use the filters with the Moondog Anamorphic lens.
There are mounting options for Go Pro’s, iPro Lenses, moment lenses, as well as camera
mounts like the Beast Grip Pro and iOgrapher.
I also received an ND 4, 8 and 16, plus a polariser filter.
If you’re unfamiliar with what ND stands for, it's short for Neutral Density and they
are designed to reduce the amount of light entering your lens without changing the colour
characteristics.
An ND 4 reduces the light by two stop, the 8 by three, the 16 by four and so on.
They use a 52mm thread and can be screwed directly onto your mount of choice.
Now let’s get back to shutter speed, and why it matters.
For DSLR and video cameras, the shutter speed makes up one part of what’s called the exposure
triangle, along with aperture and ISO - and the photographer or videographer uses an interplay
of all three of these to achieve correct exposure and the desired look.
The shutter speed determines how long each frame of your video is exposed for, and is
measured in fractions of a second, for example 1/48th of a second - and you can use shutter
speed to control the motion blur, or lack there of in your shot.
The aperture relates to how open or closed your lens’ iris is.
The wider the aperture, the more light it lets in to your cameras sensor, and as this
is stopped down, the amount of light captured is decreased.
Lastly the ISO adjusts the electrical sensitivity of your sensor, but as this is an electrical
adjustment, it introduces digital noise that can look ugly as the sensitivity is increased
to capture more light.
As we’re shooting on a smartphone, adjusting the aperture on our lens isn’t an option,
as this is fixed due to the tiny size of the lens, thus depriving us of a very useful exposure
and depth of field control.
This leaves us with just shutter speed and ISO to control our exposure.
Most of the time, smartphone videographers let the app automatically set both of these
values for them.
In FiLMiC Pro, or any other video app with manual controls, when we drag our exposure
reticle to set our exposure - the app automatically selects the best combination of ISO and Shutter
Speed to correctly expose for that point in our frame, and we hit record without actually
checking to see what these are.
If I tap and hold on the exposure reticle to open the manual adjustment slider, you
can see that if we check our settings in sunny outdoor conditions, we have the lowest possible
ISO value, which is great as it will produce the cleanest image, however if I tap the shutter
icon, you can see that to correctly expose this scene, a shutter speed of anywhere between
1/2000th to 1/4000th of second is used.
Why is this a problem?
Well the shutter speed has a direct impact on the quality of motion in your shot.
If you want the most film like motion blur, then you should always set your shutter speed
so that it's double your frame rate.
If your shooting at 24 frame per second, then you want a shutter speed of 1/48 of a second.
If you're shooting at 25, then 1/50th is ideal, and so on.
If you are wondering where this rule comes from, it can traced back to film cameras which
since the advent of synchronised sound have always shot at 24 frames per second, and used
a physical 180 degree shutter, which meant that each frame of film was only exposed for
1/48th of a second.
As the cinema going public has become accustomed to this, we have been conditioned to perceive
this as normal, and as a result we associate it with the ‘film look’.
Here is a shot filmed at 30 frames per second with a shutter speed of 1/60th.
You can see we get a nice natural motion blur, and if I freeze the frame, this motion blur
becomes obvious.
Here is the same shot filmed with a shutter speed of 1/500th of a second.
You can see we loose that smooth motion blur and get a much sharper, yet more jittery shot.
If we freeze frame, you can see how much shaper the motion is on a frame by frame basis.
Lastly, here is the same shot with a shutter speed of 1/2000th of a second.
Each individual frame is even sharper as it is only being exposed for 1/2000th of a second.
This is great if shooting sporting events where you want to be able to extract ultra
sharp still images, but in terms of its representation of motion, it just isn’t what we associate
with the film look.
However if I try to simply reduce my shutter speed to 1/60th of a second in FiLMiC Pro
in daylight conditions, the shot is completely blown out, even with the lowest ISO selected,
and not having a lens with manual aperture we can step down, we have no choice but to
shoot at an incredibly high shutter speed to achieve correct exposure.
And this is why ND filters are invaluable for bright conditions.
If I attach the ND 16, I reduce the amount of light entering the iPhone lens by four
stops, and can lock in the perfect shutter speed to achieve beautiful filmic motion even
in sunny conditions.
The great thing about the Moondog ND Filters is that you can screw multiple filters together
to cut out even more light.
So that is ND Filters in a nut shell.
Incredibly powerful for all filmmakers, but especially for smartphone filmmakers who are
deprived of one element on the exposure triangle, namely aperture, but who want to capture the
cinematic motion blur that results by maintaining the correct relationship between frame rate
and shutter speed.
If you enjoyed this video please like, share and subscribe to Epic Tutorials for more,
and I’ve linked to Moondog Labs in the description if you want to find a filter kit for your
shooting setup, as well as a link to FiLMiC Pro on the app store, if you want a professional
video solution on iOS or Android.
My name's Eliot Fitzroy and you can connect with me on Snap Chat, Instagram and Twitter
to talk smartphone media production, and I’m happy to answer any questions in the comments
field below.
Thanks for watching.