Shutter Angle Vs. Shutter Speed

[James Kuhn]

I come from a 'Still Image' background and have become comfortable with using 'minutes, seconds and fractions of seconds' in exposure. I understand the 'principle' of the 'Shutter-Angle' and how it came to use in motion pictures. However, I was reading a Sony 'brochure' from the EU and it seems to indicate there is something 'magical' imparted to the image when an Angled Shutter is used. Here's a portion of the paragraph.

BTW, the reason I ask in this 'sub-forum' is this has to do with a PMW-200 XDCAM. But, it is just a 'general' question.

"By using the angle shutter, the ratio between the exposure term and a frame term is always consistent, whatever frame number per second is selected in Slow and Quick motion, ...the 'intermittent effect' is consistent, ..."

I've decided to use 'Shutter-Angle', frankly it's easier. But, is there some 'magical' property imparted by the 'Shutter-Angle' that doesn't occur when an electronic shutter is used?

I'd appreciate any insight you might be willing to share.

Thanks in advance,

J.

[Doug Jensen]

There's nothing magical about shutter angle, but it can be a labor-saving tool for times when the frame-rate is changed.

Conventional wisdom says you should usually have a shutter speed that is twice as fast as the frame rate. In other words, 1/48 for 24P and 1/60 for 30P. And both of those speeds are equal to a shutter angle of 180 degrees. So if you simply choose 180 degrees, you may never have to pay any attention to changing the shutter seed if you change the video format. Also, if you shoot at higher frame rates, such as 60 fps or 120 fps, then a 180 degree shutter angle will automatically invoke a higher shutter speed without any effort on your part. (Of course, you'll have to decide if that is really wanted or not).

So, shutter angle might be a time-saving mode IF you want your shutter speed to change automatically when when you change the frame-rate. Personally, I'd rather change the shutter speed myself at my own discrection since I don't really agree with the conventional wisdom about recommended shutter speeds.

[James Kuhn]

Thanks, Doug! I hate to admit, but my motivation, is 'laziness'. Set it, and forget it. But, I understand what your saying. In fact, I remember you saying you've begun using 1/60th for 23.98P Scan-Mode, rather than 1/48 or 180-degree Shutter-Angle. That's a creative choice you've made.

I thought maybe, an Algorithmic function continually monitored the 'ratio' between the 'exposure term' and 'frame term' and in some creative way, making it 'more accurate' or 'cinematic'.

Essentially, both methods seem equally accurate. At this point in my 'education' it's more important for me to get consistent results and to understand why I'm getting those results. When I fully comprehend all of 'whys and wherefores', then I'll feel more comfortable varying from the 'norm'.

Besides, 'normal' is just a setting on the dryer. : )

I really like the new PMW-200 and your training DVD has been invaluable.


Best regards,

J.

[Garrett Low]

James, as you and Doug say using shutter angle could be a time saver or if you forget to change your shutter speed when changing your frame rate it could help. But remember, choosing your shutter speed is one of your creative decisions. I often intentionally don't shoot 180 degrees to achieve a look. Also, for me, prior to rolling every take, checking shutter speed along with all the other usual settings has just become part of my routine. I'm not familiar with the pmw-200 but on the EX3 adjusting shutter speed is very quick.

Just my way of doing things and everyone has their own practices so you have to do what works for you. But setting the time that the shutter isn't any more accurate if you use shutter speed or angle.

[Alister Chapman]

Do remember that in many instances you will want the shutter speed to be a direct multiple of the frequency of the mains electricity if shooting under artificial lights to prevent flicker or rolling dark/colored bands. So in 50Hz countries (Europe, Middle East) you want 1/50, 1/100, 1/200 etc. In the US and other 60Hz countries you want to be at 1/60, 1/120, 1/240 etc.

180 degree shutter is a hang over from film days where on many cameras you had no choice other than to shoot with a shutter speed effectively 2x the frame rate. Many people believe that using shutter angle rather than degrees makes them a film maker rather than a camera operator. The notional, must shoot with the shutter at 2x frame rate simply comes from the fact that if you shoot at 24p with a 1/24th shutter any motion or camera movement will make the images blurry due to the very long shutter opening. Provided your shutter speed is at least 1/50th this problem is dramatically reduced. I doubt very much whether anyone can actually tell the difference between 1/48, 1/50th or 1/60th just by looking at the footage. Working in degrees causes more problems than it cures as you are more likely to run into mains frequency miss-sync problems as it's very hard to figure out what shutter you might need if shooting lets say 24fps in a 50Hz country in degrees, compared to just setting the shutter to 1/50.

[James Kuhn]

Wow! What an incredibly thoughtful response from three of the 'heavy-hitters' on DVInfo. Thank you gentlemen! You've all given me pause to think. And, as usual, there is no single 'correct' answer to the question. It depends. As our UK 'cousins' say, "Horses for courses.". It's up to me to be flexible and knowledgeable enough to know when and where to use the various features of the camera, which is a whole other discussion. And we all know this comes with time and system familiarity.

Garrett, I had to get my camera to verify, but it appears to be equally easy to change 'shutter-angle' or 'shutter-speed' with the PMW-200 as the EX3, although I'm not familiar with the EX3.

By accessing the PMW-200's 'Direct Menu' you can change back and forth from 'angle' to 'shutter' and adjust the values to the desired setting. In Doug's 'XDCAM HD422' training video he highlights this feature, in-depth, explaining just how cool of a feature it is. He returns to the 'Direct Menu' numerous times throughout the DVD. So far, I find the 'Direct Menu' a great tool.

Again, thank you all for taking an interest in my question and quite frankly, my education.

Best regards,

J.

[Robin Probyn]

James not sure about the PMW200. But if you can make a custom menu page it also makes life very easy for menu stuff..all the things you need,plus the assignment buttons for settings you use a lot..

re shutter angle/time.. if your shooting in your own country the whole time then 180 degree can be useful to know you always have "half" shutter for any frame rate..(panasonic actually have a "half" setting in their menu) but if your traveling around abroad shooting, the time shutter function is the best way to quickly know how to avoid flicker..

[James Kuhn]

Alister...thank you for the detailed and thoughtful response. Yes, I'm 'aware' of the different Power Grid issues in other parts of the world, but it never dawned on me until you mentioned how it will affect your video capture. I've never worked a 'video gig' outside the USA, so this 'tid-bit' of information will go into my 'file'. I try to capture any and all 'tips, recommendations and standard practices' generous folks like yourself and others, are willing to share. You response will go into a file for future reference. I can't thank you enough.

BTW, I'm a videographer/Camera Operator, for now. : )

Best regards,

J.