Shutter Angle

[Robert Sawin]

First off I just wanted to thank you for your wisdom on the last forum I posted. :)

 

Ok, So I am a Student at California State University Fullerton taking cinematography course. have a question on shutter angle. This is new ground for me and I'm trying to understand how to compensate shutter angle along with f stop and/or frame rate. As I read one of my cinematography books, it seems to suggest manipulating the f stops. I am planing to shoot in two weeks and I would like to make use of shutter angle. I want to test 180 degree 90 degree and 45 degree angle. I also would like to make use of shutter speed. Possibly, shoot at 72 shutter speed or 48 shutter speed. I plan to shoot on Kodak color reversal film. I have trouble finding a proper description and image of what exactly shutter angle does and what it is. Many of these descriptions that I see are vague.

 

I heard that saving Private Ryan used a 45 degree shutter angle. so I have an idea of what shutter angle does but not a whole lot. I wonder if shutter angle is similar to a very fast shutter speed on a digital camera like 10,000s of a second. At 10,000s on the second it appears to my eyes as sharp and almost strobe like.

 

Any suggestions or guidance would be greatly appreciated.

 

Thanks

Robert Sawin

[Saul Rodgar]

I wonder if shutter angle is similar to a very fast shutter speed on a digital camera like 10,000s of a second. At 10,000s on the second it appears to my eyes as sharp and almost strobe like.

 

Thanks

Robert Sawin

 

Not really. At 24fps motion picture your shutter speed would be 1/48 th of a second still photography time.

 

http://wiki.answers.com/Q/How_do_you_contr...angle_in_camera

 

http://en.wikipedia.org/wiki/Shutter_angle

 

Also, searching for the subject on this website would be wise before posting. It only has been answered a million times before. ;)

[Andrew Brinkhaus]

The term "shutter speed" is most commonly used in conjunction with digital shooting, where the speed of the shutter is being represented as values in fractions of a second, ie. 1/48, 1/60, 1/100. "Shutter angle" corresponds to a film camera where the shutter is generally a circular rotating disc, think of this like a pie diagram. The amount missing is that which transmits light through to the film gate. With 360 degrees being the full shutter, the standard angle for motion picture is 180 degrees, or what would translate to 1/48th of a second in shutter speed. As you decrease the angle of the shutter, 90, 45, etc. you are allowing less light to enter the film gate while the film still travels at the same speed, say 24fps. The result is a stroby, sharp and "accelerated" feel as opposed to a smoother softer result in movement at 180 degrees. A 45 degree angle was commonly used in SPR for that specific effect. Shutter speed and shutter angle can be connected in that as angle goes down, shutter speed would go up, (1/120th, 1/250th, etc) 180 degrees meets with 1/48, 90 degrees meets roughly with 1/120th and 45 meets around 1/250. Because at a smaller shutter angle, you are allowing less light into the gate, so compensation is always necessary when shooting outside 180 degrees.

 

Here is a rough layout of compensations for shutter angle. Happy shooting!

 

 

180° - 0 stop compensation

 

142° -1/3 stop

 

113° -2/3 stop

 

90° -1 stop

 

71° -1 1/3 stop

 

57° -1 2/3 stop

 

45° -2 stops

 

36° -2 1/3 stops

 

28° -2 2/3 stops

 

22° -3 stops

Edited September 18, 2008 by Andrew Brinkhaus

[Robert Sawin]

The term "shutter speed" is most commonly used in conjunction with digital shooting, where the speed of the shutter is being represented as values in fractions of a second, ie. 1/48, 1/60, 1/100. "Shutter angle" corresponds to a film camera where the shutter is generally a circular rotating disc, think of this like a pie diagram. The amount missing is that which transmits light through to the film gate. With 360 degrees being the full shutter, the standard angle for motion picture is 180 degrees, or what would translate to 1/48th of a second in shutter speed. As you decrease the angle of the shutter, 90, 45, etc. you are allowing less light to enter the film gate while the film still travels at the same speed, say 24fps. The result is a stroby, sharp and "accelerated" feel as opposed to a smoother softer result in movement at 180 degrees. A 45 degree angle was commonly used in SPR for that specific effect. Shutter speed and shutter angle can be connected in that as angle goes down, shutter speed would go up, (1/120th, 1/250th, etc) 180 degrees meets with 1/48, 90 degrees meets roughly with 1/120th and 45 meets around 1/250. Because at a smaller shutter angle, you are allowing less light into the gate, so compensation is always necessary when shooting outside 180 degrees.

 

Here is a rough layout of compensations for shutter angle. Happy shooting!

 

 

180° - 0 stop compensation

 

142° -1/3 stop

 

113° -2/3 stop

 

90° -1 stop

 

71° -1 1/3 stop

 

57° -1 2/3 stop

 

45° -2 stops

 

36° -2 1/3 stops

 

28° -2 2/3 stops

 

22° -3 stops

 

your explanation was very helpful; however I have one more question regarding shutter angle. I think you may have mentioned it, but I need one more clarification.

 

Here's my question.

 

So if I shoot at a 45 degree angle while understanding -2 f stop must be compensated, can I achieve the same effect by increasing the shutter speed to create a slow-motion effect while shooting at 45 degrees. essentially does a faster shutter speed compensate the need to subtract light. And if so what kind of effect do you think This setting may result in. I want to see if I could do both.

 

Thank you

Robert Sawin

[Andrew Brinkhaus]

Robert I think you have some things confused, shutter speed and shutter angle mean the same thing essentially, one term is used more in digital, the other in film. If you are referring to shooting a higher frame rate to create a slow motion effect, yes you can do that in conjunction with the 45 degree shutter, you will not alleviate your light loss problem by doing that, as higher frame rates require MORE light. So essentially you will be losing 2 stops at 45 degree shutter and then say another stop if shooting 48 frames per second.

 

Check out Saul's links if you are still not totally connecting all this.

[Robert Sawin]

Robert I think you have some things confused, shutter speed and shutter angle mean the same thing essentially, one term is used more in digital, the other in film. If you are referring to shooting a higher frame rate to create a slow motion effect, yes you can do that in conjunction with the 45 degree shutter, you will not alleviate your light loss problem by doing that, as higher frame rates require MORE light. So essentially you will be losing 2 stops at 45 degree shutter and then say another stop if shooting 48 frames per second.

 

Check out Saul's links if you are still not totally connecting all this.

 

thank you I understand now. I will take this into practice.

 

Robert Sawin

[Simon Wyss]

Hey, Robert

 

You are at the heart of cinematography, technically. What I can tell you is most simple: Do shoot and look at your moving pictures in projection, I mean big, perhaps in a cinema where you find a friendly projectionist. One has to have seen the various effects of different shutter angles on people walking, on horses galloping, whatever in motion. Forget the theory for a while and dive into practice !

 

Only one more thing. Until today the longest shutter opening with a cine camera is still 230 degrees. No one knows how a film might look when exposed with, say: 340 degrees.

 

Simon