EX1 1080 30p - Shutter on.... or off?

[Jonathan Bland]

Hey Folks,

Shooting a feature doc for for broadcast in North America.

I'm thinking that 1080 30p is the way to go. Does anyone have a comment on the shutter and whether or not to turn it off..... or leave it on?

In this case.... If I understand correctly when the shutter is off, the shutter speed defaults to 30fps when shooting 30p. Right?

I can imagine turning it on when there is more movement like shooting from a moving vehicle.... but what about walk and talks? Comments?

Is there a preferred shutter speed when the shutter is employed? 1/40, 1/50/ 1/60, 1/125, 1/250? For slower subject matter? For faster subject matter?

The project will include both handheld and tripod...... lots of travel.

I'm going to reduce detail to -25 and shuffle between Cine1 and Cine4.

Any thoughts or comments would be greatly appreciated :)

[Michael B. McGee]

when the shutter is turned off at 30fps, i believe the speed is 1/30. basically a 360 degree shutter. so a 180 degree shutter at 30fps would be 1/60. the shutter setting is for speed not frame rate. try using 1/60 or 180 degrees. that seems to be the most common at that frame rate for "normal" shooting. speed it up or down for some effects.

enjoy.

[Eric Darling]

Most typical shooting scenarios would call for a 180 degree shutter. So, if you're rolling 30p, you'd have a shutter setting of 1/60. You have to think of a shutter setting as you would with a mechanical camera - this is just the electronic equivalent of the shutter setting. In a mechanical camera, there's a spinning disc that is half clear and half opaque. This disc spins at the rate that its set to allow light to be blocked while the film advances to the next frame. Higher settings can be used with great effect to give a more staccato look. Lower settings add motion blur for a more smeary/dreamy/inebriated look. But, when you don't want the shutter to have a noticeable effect, use it at 180 degrees. At 24 fps, this would be 1/48. At 25, 1/50, and etc. If you keep the shutter off (360 degree shutter), you will notice more smeary motion on higher action sequences, and when the camera pans. But, if you're shooting a talking head, for instance, or other similarly static scene, you might be able to use a 360 degree shutter without really noticing. This is a good trick to allow more exposure when light is low. Just make sure you're getting what you want in terms of pretty pictures. :)

The basic thing to remember is lower shutter = more exposure and blur. Higher shutter = less exposure and sharp.

[David Issko]

sony has a few short 'training' videos posted. one covers progressive recording. the short video shown has shutter switched off. the voiceover instructs the user to turn the shutter off.

i have been recording in 1080 25p for some months and all i found in the early days was a drop in exposure when i switched in 1/50 shutter. did not value add to the image quality in any way.

i have since worked 1080 25p with my shutter off.

you may require different settings, depending on the genre of program you are shooting.

best wishes

[Andy Wilkinson]

If you shoot under mainly flourescent lights (which I sometimes HAVE to do for corporate video work - office environments etc.) then it's important to set the shutter to match the frequency of the power supply to avoid unsightly and totally unusable resulting images because of banding/phasing effects. In the UK that means 1/50 sec shutter but 1/60th in US for these situations.

Apart from that I tend to shoot mainly with shutter off as it imparts a little motion blur which makes the flow of movement slightly better in most cases and, as already stated, gives you a little better low light flexibility with EX1 and EX3.

But it really depends what you want to do and the look you're after. Sometimes, for technical slow motion work it's better to have no motion blur (shutter on) and do it at a high shutter speed setting to capture each frame as clearly as possible - if the intention is to extract those frames for scrutiny afterwards, e.g. sports training where a freeze frame could be shown for a period of time in the final output. Some good points in this other new thread here too.

http://www.dvinfo.net//conf/showthread.php?t=145093

[Jonathan Bland]

A big thanks to everyone who chimed in here :)
If anyone else wants to add to this please jump in......

[Mitchell Lewis]

I have trouble telling the difference between the look of shutter on and shutter off. With shutter on the video has a bit more of a strobed look to it. I haven't tried doing any slow motion yet, but I would think that having the shutter on would help like it has on other cameras I've used. Here's how I decide when to turn the shutter on or off:

Low light situation = shutter off
Most other situations (plenty of light) = shutter on at 1/60th (1080 30p)

I shoot with a Letus Ultimate adaptor which reduces the light level a bit, so I find myself shooting with the shutter off quite a bit and my footage always looks great.

[Alister Chapman]

I almost always shoot with a 180 degree shutter as I don't like the soft pictures I get without the shutter if there is any camera movement or moving objects within the scene.

[Mike Barber]

I'm trying to wrap my head around the the whole shutter speed vs angle thing right now. As I mentioned in a recent thread, I am under the understanding that when shooting 24p, I would want to stick with a shutter speed of 1/48. This makes obvious sense for the same reasons I always shoot (NTSC) DV at 1/60.

Shooting 24p is brand new to me as is using the EX1, so I have been trying to bone up on the little details such as shutter speed vs angle. 180°, 360°... this doesn't mean anything to me, so I am a bit lost, which concerns me. I am at least aware that the wrong shutter speed and/or angle could undo one's efforts to achieve a certain temporal feel.

Stu Maschwitz has a post on his blog about the film Reverie which also touches on this very subject:

Film usually has a shutter speed of 1/2 the frame duration, e.g. 1/48 second shutter speed for 24 fps. Video, unencumbered by a physical shutter, often has a shutter speed equal to the frame rate. The most video-like sections of ["Reverie"] are those with 1/30th shutter speeds.

This issue plagues many 24 fps HD examples as well. Even at 24p, a “360 degree shutter” results in too-smooth motion with a video-like appearance. You may have seen this in some Hollywood movies shot with 24p HD cameras. It's not the dynamic range or resolution that blows it for digital movies—it's a simple choice to use a shutter speed impossible on a film camera.

I’m not trying to critique Vincent's beautiful piece at all, just hoping to preemptively answer the question of why some 30p samples can indeed look filmic, and some don’t.

I'm also seizing this opportunity to discuss the 360 degree shutter issue, as it's one that needs airing out. Sure, it may be a creative choice for a filmmaker to use a greater-than-180-degree shutter, but when my mom sees the trailer for Collateral and asks me why it looks like video, we're talking about a choice that sets back the progress of digital cinema. If you want your 24p HD to look like film, the film we know and love, stick to a 1/48 second shutter speed or faster.

It gets right back to good old less is more—not only is 24p a minimal frame rate, it turns out that a big part of the signature film look is that you only see half the motion in each of those 24 frames per second.

I certainly want to maintain the temporal feel of film. the subject is a very intense and heavy subject, which I feel warrants the specific aesthetic choices I have made. So, how do I translate my understanding of shutter speeds described in fractions into terms in angles?

[Mike Barber]

Pages 43-44 of the EX1 manual list the shutter speeds and angles. For 24p, the available speeds are 1/32, 1/48, 1/50, 1/60, 1/96, 1/125, 1/250, 1/500, 1/1000, and 1/2000. The available shutter angles (in 24p) are 180°, 90°, 45°, 22.5°, and 11.25°.

I see the patterns in successive steps up and down, but I don't know how to correlate the speed values with angle values.

[Michael B. McGee]

180 degree shutter = 1/(frame rate) x 2
180 shutter @ 24P = 1/24x2= 1/48

don't worry about shutter angles if you already know what certain speeds do.
......... tomato, tomatoe

[Serena Steuart]

Sony provided shutter angle because film shooters are used to working with cameras that have mechanical film transports. In these cameras the pull down movement is geared to the shutter shaft, such that typically one frame pull down occurs with each rotation of the shutter. So the shutter shaft rotates at camera frame rate and the film is exposed during the open shutter sector. Any professional camera has a variable or settable shutter angle, variable between 200 deg and 10 deg open (maybe down to closed). So the shutter speed = (angle/360)/fps.
For 24 fps, 180 deg shutter, shutter speed = 180/(360 x 24) = 1/48 sec.

EDIT: I guess it is obvious, but in film cameras the variable shutter is there for a reason, and it is wrong to say that at 24 fps film is always shot with a 180 deg shutter.

[Alister Chapman]

The difference between using a shutter angle as opposed to fixed shutter speed is that if you change the frame rate and you are using shutter angle the shutter speed will track the frame rate. So if you switch say from 24P (1/48th at 180 degrees) to 30P the shutter will change to 1/60th without you having to do anything.

[Serena Steuart]

good point.