Cinematography & Cameras

What are Shutter Speed and Shutter Angle

What are Shutter Speed and Shutter Angle

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What is shutter speed? What is shutter angle, and how do you use both creatively for the film look? This video explains it all.

If you’re shooting 24p or 24 frames per second video, you should set your shutter to 1/48th shutter speed or 180 degree shutter angle.
Photo cameras usually only have shutter speed as an option.  Both shutter Angle and shutter speed are usually available in cinema cameras.

Now variety of shutter speeds can be used in photography, video and film cameras.  If you go higher, you will get less motion blur.  For example, 1/1000 will have very little motion blur and 1/24 will have a good deal of motion blur.  1/48th is the standard, because it’s the amount of motion blur we are used to seeing in most motion pictures during the last 100 years.  So 180 degree or 1/48th shutter is that desired film look we all want.  It’s just what we are used to.  It’s not a rule.

In latest digital and mirrorless cameras, the closest option is 1/50th which is close enough to 1/48th and the difference is hardly noticeable.

If you don’t want a film look, you can experiment and try a different shutter speed.

If you’re shooting with higher frame rates, let’s say 120 frames per second, double the shutter speed if you want to resemble a film look.  So in this case, it would be 1/240th.  Using this math, you will lose a lot more light.  So if you need more light, you will have to compromise and possible shoot at 1/120th shutter speed.  Don’t let the so called rule of shutter speed should be twice the frame rate hold you back.  Use shutter speed to tell your story and experiment with it.

Video from Wolfcrow
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Hi I’m Sareesh Sudhakaran and in this video I’ll try to explain, as simply as I can, what shutter speed is, in relation to film and video, and how to choose a shutter speed to get the film look.

Let me start with a popular example. If you want to shoot 24 frames per second, or 24p, you’re usually advised to have your shutter at 1/50th of second or at a 180-degree shutter angle. Most photography cameras that shoot video only have the shutter speed as an option while cinema cameras might give you shutter speed and/or the shutter angle.

Why should you have your shutter at 1/50thof a second or at 180 degrees? Is it a rule etched in stone? Not really, you can have any shutter speed as long as it is physically possible. Here’s what the traditional film camera shutter did when shooting 24 frames per second. Mind you, there were other shutter designs as well, so it’s a lot more complicated than this, but for the present, this is good enough. You can see that the film is exposed for a certain time, that’s when the shutter is open, and is closed for an equivalent amount of time, when the shutter is closed.

There’s a physical limit to the shutter size, one that we can denote through an angle. A full circle is 360 degrees, and nothing is 0 degrees. You really can’t have a shutter beyond these limits, for film. So a 180-degree shutter is when the frame is open to light and closed to light for an equivalent amount of time. So if you’re shooting 24 frames per second, each second is divided into 24 frames, and each frame can have a maximum duration of 1/24s.

But since each frame has an opening period, that’s when the shutter is really open, and a closed period, the shutter speed corresponding to this 180-degree shutter is half of 1/24s, which is 1/48s.If you’ve watched my previous video on the exposure triangle, I had explained what the shutter is, and why it should be opened and closed for exposure. If you keep the shutter open for a 180-degree shutter angle, you geta certain kind of motion blur. By the way, motion blur is nothing but still image blur that you get for keeping the shutter open that long. If you want less blur, you have to have a faster shutter speed, and if you want more blur, you keep the shutter open longer. Both are possible, as long as it’s between 0and 360 degrees for a film camera.

But for better or for worse, when we say we want the film look, at least as far as shutter speeds are concerned, we need a 180-degree shutter angle for 24 frames per second, or a shutters peed of 1/48th of a second. This is how we have been programmed through more than a century of films.

There’s no rule that says a shutter has to be a 180-degree shutter, it’s just the norm, that’s all. Now let’s come to modern digital cameras that don’t have rotary shutters. Many modern video cameras have electronic shutters.

We don’t need to know how they work, just what the results are. If you look at modern DSLRs and mirrorless cameras, you’ll see a shutter speed of 1/50s, and the next best option is only 1/40s or can round it off to 1/50s because perceptibly the small difference in motion blur is not noticeable by anyone. So that’s why people recommend a shutter speed of 1/50th of second to mimic the 180-degreeshutter angle when shooting 24 frames per second, so this gives you the best approximation of the film look.

What do I mean by approximation? The thing is, a rotary shutter opens and closes in a certain way, and electronic shutters have a completely different mechanism. That’s why a cinema camera like the Sony F65 has a rotary shutter to simulate the exact motion characteristics of film cameras. So if all you care about is shooting 24 frames per second to get the film look, keep the shutter speed at 1/50s or 1/48s, or the shutter angle at 180-degrees or 172.8 degrees, and you’ll get the film look.

I’ll provide the formula for conversion between shutter speed and shutter angle in the article that goes with this video. If you are interested in knowing more, then ask yourself: What if you’re shooting at and you’ll get a frame size of 1/30th of a second. To replicate a 180-degree shutter you’ll need to halve that, or set your shutter speed to 1/60th of a second. Now some of you clever guys might ask a very valid question: If you want the same motion blur as 24 frames per second when you’re shooting 30 frames per second, shouldn’t you stick to 1/50thof a second shutter speed? Wouldn’t that give the same motion blur as 24p? Yes, it would!

Which brings me to the rule floating around on the Internet that says your shutter speed should always be one by twice your frame rate. I’m sorry to say that rule isn’t really true. It’s only true for 24 frames per second. For 30 frames per second, you can have your shutter at 1/50 or 1/60th of a second, and it’s a matter of taste. Ultimately though ,the difference is so small most people won’t notice it, in this case. Here are some common frame rates and the shutter speeds you can choose for them – for the film look: [23.976/24 – 1/48 or 1/50s, 25fps – 1/50s, 29.97/30 fps – 1/50s or 1/60s].

The key work here is ‘film look’. What if you don’t want the film look? You are free to deviate from these shutter speeds and you can get different effects. E.g., let’s go back to 24 frames per second. When we divided one second by 24, each frames a maximum of 1/24s, so you can’t go slower than that on a film camera. But on a digital camera, like say the Sony a7S II, if I seethe frame rate to 24p, it allows me to group to 1/4th of second. How is that possible? To be honest I don’t know the real answer, but if I have to guess I’d say electronic shutters are independent of the frame rate to a certain extent.

Also, the sensor readout on modern cameras is much faster than the frame rate, and this is what possibly allows the camera to go further. Fascinating stuff. Modern cameras can keep the shutter open for multiple frames, and is not physically restricted like a film shutter. This means you get far more versatility with digital cameras than film cameras ever had. I used up to a 1/6s shutter speed for a portion of a fashion video I shot last year, and films like Saving Private Ryan and Gladiator managed to get this strobe-like dream-like effect with the same technique, except they shot on film.

Keep in mind, once you do this in camera, you can’t undo it. It’s permanent. On the other hand, what if you wanted to speedup the shutter? You can do that too. You don’t have to keep the shutter at 1/50s if you’re not strictly after the film look. You can close it down to 1/60s or 1/120s or whatever the camera will allow you to do. The Sonya7S II allows you to go all the way to 1/8000s, its maximum.

In still photography, if you want a crisp frame without motion blur, you are told to speed up your shutter. The lesser the time the sensor is open to motion, the less the blur. If you speed up the shutter for video, you will have less motion blur. Here’s an example of a shot at 24 frames per second with a 1/120s shutter speed. You can see the motion looks choppy, like there are break-in the movement. So, a slower shutter speed will give you dream-like motion blur-heavy effect, and faster shutter speed will give you a choppy mechanical effect.

Now there’s a catch. The speed of an objecting the frame will also play a role here. Something moving much faster will deliver a higher motion blur than something moving slower. So does that mean a slower object with a faster shutter will have the exact same look as a faster object with slower shutter speeds? Not really. They’ll look a bit different. Whether or not it’s acceptable, is your call. E.g., you might have often noticed a film panning shot where everything goes blurry, and this irritates you. That’s because the speed of the pan is too fast, and each frame has too much motion blur.

By speeding up the shutter, you can increase the speed with which yaupon the camera. Moving forward, there’s another popular misconception that 24p or 1/50th of a secondi’s equal to what the eyes see, or that it’s the most natural look. That’s bullshit, fortunately. If you really saw that much motion blur in real life you’ll be puking your eyes out. I’ve written an article before on what the frame rate of the eye is roughly, and it’s definitely more than 60 frames per second. Which is why sports, modern games running at 60 fps or The Hobbit running atman experiment several years ago where he fixed the frame rate of the eye close to 72 fps. Ang Lee took it to 120 frames per second.

My own experiences suggest 60 fps is possibly good enough. Also, you must understand that we’ve been watching movies for more thane hundred years with mostly a 180-degree shutter at 24p. We’re used to that level of motion blur. But we also watch sports interlaced which is similar to motion at 50 or 60 fps. We have a latitude of tolerance for shutter speeds, and to say only one speed looks normalize a mistake. Which brings us to high frame rates. What shutter speed should you pick if you’re shooting 50, 60 or 120 frames per second, or higher?

Divide a second by the number of frames. E.g., let’s take 120 fps, a popular high-speed number. Each frame is then 1/120th of a second. Toucan’s go below this, so you’ll never get filmic motion blur. If you follow the 180-degreeshutter rule, the shutter speed should be exposure for a scene at 24 fps and 1/50thshutter, and suddenly you decide to shoot something in high speed at 120 fps and unclose down the shutter to 1/240th of a second. What happens? You just lost more than two stops of light. That’s four times the light, which is a lot. So the next big question is, why are we following the 180-degree rule here? Why not just shoo tat 1/120s? Valid question, and the answers, you can, if you don’t want the film look. If you want the film look, chances are you’ll be using the 120 fps footage on want the motion to resemble what you’d get on a film camera that could shoot 120 fps. It’s your call.

You can use shutter speed to achieve two things: Control motion blur for a film look, or control exposure, just like you do for photography. It’s a compromise. Sometimes you’re shooting and you quickly need to adjust exposure, adios and aperture are not going to cut it, should you change the shutter speed? It’s your call.

Can you live with the change in motion blur? That’s the bottom line. The smart thing to do is to test your camera at different frame rates and shutter speeds, and then study it on a proper monitor. Many cheap monitors can’t display motion properly, so try to study it on a monitor that can display the frame rate the way it should look. And high frame rate video is never played back at those high frame rates. The objective into slow them down on a 24p timeline most of the time. If you choose to change shutter speeds from shot to shot you might have issues matching them when editing. It’s something you need to be aware of.

So is there an advantage in having a faster shutter speed? Anything with action works. That’s because the subject in the shot is moving faster than they would normally. You can follow a football, racecar or a fast sidekick with a faster shutter speed. Also, if the shot is only a few frames long, and is part of a fast-paced edit, most people won’t notice the change.

The next use for a faster shutter speed is event coverage. Sometimes you might be asked by a client for still frame grabs from the video. In this case it’s better to shoot at a faster shutter speed. You treat it like you’re shooting 24 photographs a second. Software like Adobe After Effects can simulate motion blur so you can correct the look some what in post, but it’s extra effort and time. Motion graphics and VFX artists use this trick all the time. The most popular use for a faster shutter speed is sports.

The traditional 180-degreeshutter angle makes it hard to follow the ball or whatever else is flying around, which is why sports are shot interlaced or at a higher frame rate with a faster shutter speed. The takeaway here is – there’s a good reason to use all shutters speeds.

Don’t get bogged down by the impractical rule that the shutter speed should always be one by twice the frame rate. If you have to get the shot, you can slightly adjust the shutter speed to compensate for exposure.

In my experience, you can vary between a third to half a stop before the change in motion blur is apparent, so you have about half a stop of leeway both ways. When I’m shooting at 1/50 and I need to stop down by a third of a stop, I don’t think twice before changing the shutter speed to 1/60s. I’ve done it a million times before and nobody has noticed, and nobody ever will. But if I have to change by another third of a stop or two-thirds, I stop myself. I have to ask myself if the subject in the frame is moving too fast or not. If it’s too fast, a faster speed will work, but a slower shutter speed will just make things worse. It’s a judgment call you need to make in a split second.

The cool thing is, just like you can use aperture to control the look of your shot, you can use shutter speeds to control the motion characteristics of your shot as well. So you can be a conformist by sticking to the norm, or experiment and create tailor-made visuals for your projects. I hope you’ve found this video useful. If you have any questions, please feel free to ask me in the comments below. If you liked this video and want more, please subscribe and don’t forget to hit the like button. To get more free stuff, visit the link you’ll see in the description. Bye now.

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