anyone shoots with 1/100 shutter? at DVinfo.net

Federico Perale · December 12th, 2010, 03:01 PM

I was trying to shoot 1/100 to fully respect the 180 degree rule for a more filmic look
but.....I don't really like the result!!

the footage looks almost jittery, and especially with cineframe 25

anyone can clarifty or chan share their experience with fast shutter times on the Z1?

John Wiley · December 12th, 2010, 04:09 PM

That's because to follow the 180 degree rule you should be shooting at 1/50th. This is true for both the cinemframe and 50i modes.

Federico Perale · December 12th, 2010, 04:53 PM

i always thought that 180 degrees corresponds to half the amount of the frame rate?

1/50 shooting at 25p, 1/100 shooting at 50 and 1/120 shooting at 60 and
so on...

"....So, since we now understand that when shooting at 1fps, the shutter speed would be 1/2, then you basically just carry that math on! 24fps = 1/48, 25fps = 1/50, 30fps = 1/60, 60fps = 1/120, 120fps = 1/240 and so on…

from this link 180 Degree Shutter - Learn It, Live It, Love It

Perrone Ford · December 12th, 2010, 05:02 PM

You were shooting at 50p?

Adam Gold · December 12th, 2010, 05:37 PM

50i on the Z1 -- whether or not you use the Cineframe 25 setting -- is 25 frames ps. So to mimic a 180 degree shutter you shoot at 1/50th.

The Z1 doesn't do any form of progressive.

Federico Perale · December 13th, 2010, 02:39 PM

Quote:

Originally Posted by Adam Gold

50i on the Z1 -- whether or not you use the Cineframe 25 setting -- is 25 frames ps. So to mimic a 180 degree shutter you shoot at 1/50th.

The Z1 doesn't do any form of progressive.

OK but on the EX1r that can do progressive and interlaced if I set it at 50i, the setting 180 degrees corresponds to putting the shutter at 1/100, not 1/50
(and if I set it at 25p, corresponds to shutter at 1/50)
what's the reason for that?

Adam Gold · December 13th, 2010, 03:21 PM

Yes, but 50i is still always really 25 frames. So for both 50i and 25p you should set at 1/50th.

But the bottom line is how it looks to you. You asked why 1/100th looks jittery, and it's because that's what it's supposed to look like. The "film look," as defined by most people, is supposed to be jittery, because that's one of the things (but only one) that characterizes the difference between film and video. So I think there's a conflict between wanting the film look and shooting in a Cineframe or other progressive/slow frame rate and on the other hand not wanting it to look jittery.

If the EX1r sets the speed to 1/100th when you set the angle to 180 degrees, then I'd say it's treating each field like a frame, and when played back in normal interlaced mode 1/100th might be ok. But others know much more about this cam than I do.

One thing is for sure -- if you are using the Cineframe 25 mode on the Z1, which simulates 25fps progressive, then you absolutely must use 1/50th.

I happen to shoot 60i and only 60i, and I have never in my life used a shutter speed other than 1/60th unless I was experimenting. If I were to shoot 30p, I'd still use 1/60th. And if for some bizarre reason I shot 24p, I'd shoot at 1/48th.

There's an extensive "Film Look" subforum here with some great information about frame rates and shutter speeds.

Perrone Ford · December 13th, 2010, 03:37 PM

Unless the behavior has changed from the EX1 to the EX1r, I think a 180 shutter on 60i gives a 1/60 shutter. I'll check my camera when I get home tonight, but there is no way it should go to 1/120.

Federico Perale · December 13th, 2010, 03:57 PM

Quote:

Originally Posted by Perrone Ford

Unless the behavior has changed from the EX1 to the EX1r, I think a 180 shutter on 60i gives a 1/60 shutter. I'll check my camera when I get home tonight, but there is no way it should go to 1/120.

please try yo make the experiment

I set it at 50i 180 degrees
I then move it to shutter 1/100...... everything stays the same_ image is identical

to move it to 1/50 I would have to turn the shutter off, and by doing so the image becomes brighter, as to confirm that 180 degrees at 50i is a faster shutter speed than 1/50

dunno if this makes sense?

Perrone Ford · December 13th, 2010, 04:48 PM

Yes, this makes sense. I have to work late tonight, but I will check the camera when I get home and report on my findings. I don't have 50i (I am in the US) but I will do this with 60i and let you know.

Perrone Ford · December 14th, 2010, 01:00 AM

Ok, so this is what I did.

I put my EX1 on a tripod, pointed it at a light source, and set the iris so that the center box indicator read at "100". The camera was set to 1/60 shutter at 1080/30p.

1. I changed to 1080/60i keeping the 1/60th shutter and there was no variation in the light level.

2. I changed the shutter to "angle" and selected 180 degrees. The light level dropped to "83".

3. I turned the shutter off, corresponding to a 360 degree shutter, and the light level was 100% again.

So it appears that if you are using "shutter angle" and keeping it constant, that exposure does in fact change when going between progressive and interlaced modes. However, if a specific shutter SPEED is selected, then changing between interlaced and the companion progressive mode, then the exposure is NOT affected.

Obviously, this would indicate that the 180 degree shutter is acting differently. A 1080/30p at 1/60th shutter gives the same exposure as 1080/30p with a 180 degree shutter. As one would expect.

Doing the same with interlaced brings different results. A 1080/60i with a 180 shutter is darker than a 1080/60i with a 1/60th shutter. The difference was exactly 1 stop. In my case a difference betewen F8 and F5.6.

So there you have it. A 180 shutter in interlaced mode is NOT truly a 180 shutter but in fact closer to a 135 shutter.

As far as I am concerned, another reason to avoid shooting interlaced. It just complicates things in production as well as post.

Federico Perale · December 14th, 2010, 12:39 PM

interestingly in another forum some other guy seem to have experienced the same

"Doing some experimenting with the new EX-1.
Trying to smooth-out the fluttery look of 1080 24p video.
Was suggested I set Speed to 1/48 or 1/50.
No real difference I can see thru the viewfinder.
1080 60i looks very smooth by comparison.
Would setting Shutter to Angle make a difference?
"
and his further comment
"Couldn't wait.
Grabbed my EX-1 and walked outside.
Set the Shutter to Angle 180.
Must say it looks MUCH nicer. Very smooth.
Will do more testing later. I'll let you know how it goes.
Thanks.
"

to which someone responded that shooting at 1/48 with 24p is the same as shooting at a 180 degrees angle but....
"Yeah, that's true..a 180 degree shutter angle exposes 1/48 ;O) It's possible though, by changing the shutter angle, as opposed to the shutter speed, you'll get a smoother look (though, again, I'm not sure how...lol).

I am really intrigued by this "fault" in the Ex1(r) that seems to defy the theory : )

December 12th, 2010, 03:01 PM	#1
Federico Perale Major Player Join Date: Apr 2010 Location: London Posts: 410	anyone shoots with 1/100 shutter? I was trying to shoot 1/100 to fully respect the 180 degree rule for a more filmic look but.....I don't really like the result!! the footage looks almost jittery, and especially with cineframe 25 anyone can clarifty or chan share their experience with fast shutter times on the Z1?

December 12th, 2010, 05:02 PM	#4
Perrone Ford Inner Circle Join Date: Nov 2006 Location: Tallahassee, FL Posts: 4,100	You were shooting at 50p? __________________ DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.

December 12th, 2010, 05:37 PM	#5
Adam Gold Inner Circle Join Date: Jan 2007 Location: Woodinville, WA USA Posts: 3,467	50i on the Z1 -- whether or not you use the Cineframe 25 setting -- is 25 frames ps. So to mimic a 180 degree shutter you shoot at 1/50th. The Z1 doesn't do any form of progressive. __________________ "It can only be attributable to human error... This sort of thing has cropped up before, and it has always been due to human error."

December 13th, 2010, 03:21 PM	#7
Adam Gold Inner Circle Join Date: Jan 2007 Location: Woodinville, WA USA Posts: 3,467	Yes, but 50i is still always really 25 frames. So for both 50i and 25p you should set at 1/50th. But the bottom line is how it looks to you. You asked why 1/100th looks jittery, and it's because that's what it's supposed to look like. The "film look," as defined by most people, is supposed to be jittery, because that's one of the things (but only one) that characterizes the difference between film and video. So I think there's a conflict between wanting the film look and shooting in a Cineframe or other progressive/slow frame rate and on the other hand not wanting it to look jittery. If the EX1r sets the speed to 1/100th when you set the angle to 180 degrees, then I'd say it's treating each field like a frame, and when played back in normal interlaced mode 1/100th might be ok. But others know much more about this cam than I do. One thing is for sure -- if you are using the Cineframe 25 mode on the Z1, which simulates 25fps progressive, then you absolutely must use 1/50th. I happen to shoot 60i and only 60i, and I have never in my life used a shutter speed other than 1/60th unless I was experimenting. If I were to shoot 30p, I'd still use 1/60th. And if for some bizarre reason I shot 24p, I'd shoot at 1/48th. There's an extensive "Film Look" subforum here with some great information about frame rates and shutter speeds. __________________ "It can only be attributable to human error... This sort of thing has cropped up before, and it has always been due to human error."

December 13th, 2010, 03:37 PM	#8
Perrone Ford Inner Circle Join Date: Nov 2006 Location: Tallahassee, FL Posts: 4,100	Unless the behavior has changed from the EX1 to the EX1r, I think a 180 shutter on 60i gives a 1/60 shutter. I'll check my camera when I get home tonight, but there is no way it should go to 1/120. __________________ DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.

December 12th, 2010, 04:09 PM	#2
John Wiley Trustee Join Date: Oct 2008 Location: Byron Bay, Australia Posts: 1,155	That's because to follow the 180 degree rule you should be shooting at 1/50th. This is true for both the cinemframe and 50i modes.

December 12th, 2010, 04:53 PM	#3
Federico Perale Major Player Join Date: Apr 2010 Location: London Posts: 410	i always thought that 180 degrees corresponds to half the amount of the frame rate? 1/50 shooting at 25p, 1/100 shooting at 50 and 1/120 shooting at 60 and so on... "....So, since we now understand that when shooting at 1fps, the shutter speed would be 1/2, then you basically just carry that math on! 24fps = 1/48, 25fps = 1/50, 30fps = 1/60, 60fps = 1/120, 120fps = 1/240 and so on… from this link 180 Degree Shutter - Learn It, Live It, Love It

December 13th, 2010, 04:48 PM	#10
Perrone Ford Inner Circle Join Date: Nov 2006 Location: Tallahassee, FL Posts: 4,100	Yes, this makes sense. I have to work late tonight, but I will check the camera when I get home and report on my findings. I don't have 50i (I am in the US) but I will do this with 60i and let you know. __________________ DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.

December 14th, 2010, 01:00 AM	#11
Perrone Ford Inner Circle Join Date: Nov 2006 Location: Tallahassee, FL Posts: 4,100	Ok, so this is what I did. I put my EX1 on a tripod, pointed it at a light source, and set the iris so that the center box indicator read at "100". The camera was set to 1/60 shutter at 1080/30p. 1. I changed to 1080/60i keeping the 1/60th shutter and there was no variation in the light level. 2. I changed the shutter to "angle" and selected 180 degrees. The light level dropped to "83". 3. I turned the shutter off, corresponding to a 360 degree shutter, and the light level was 100% again. So it appears that if you are using "shutter angle" and keeping it constant, that exposure does in fact change when going between progressive and interlaced modes. However, if a specific shutter SPEED is selected, then changing between interlaced and the companion progressive mode, then the exposure is NOT affected. Obviously, this would indicate that the 180 degree shutter is acting differently. A 1080/30p at 1/60th shutter gives the same exposure as 1080/30p with a 180 degree shutter. As one would expect. Doing the same with interlaced brings different results. A 1080/60i with a 180 shutter is darker than a 1080/60i with a 1/60th shutter. The difference was exactly 1 stop. In my case a difference betewen F8 and F5.6. So there you have it. A 180 shutter in interlaced mode is NOT truly a 180 shutter but in fact closer to a 135 shutter. As far as I am concerned, another reason to avoid shooting interlaced. It just complicates things in production as well as post. __________________ DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.

December 14th, 2010, 12:39 PM	#12
Federico Perale Major Player Join Date: Apr 2010 Location: London Posts: 410	interestingly in another forum some other guy seem to have experienced the same "Doing some experimenting with the new EX-1. Trying to smooth-out the fluttery look of 1080 24p video. Was suggested I set Speed to 1/48 or 1/50. No real difference I can see thru the viewfinder. 1080 60i looks very smooth by comparison. Would setting Shutter to Angle make a difference? " and his further comment "Couldn't wait. Grabbed my EX-1 and walked outside. Set the Shutter to Angle 180. Must say it looks MUCH nicer. Very smooth. Will do more testing later. I'll let you know how it goes. Thanks. " to which someone responded that shooting at 1/48 with 24p is the same as shooting at a 180 degrees angle but.... "Yeah, that's true..a 180 degree shutter angle exposes 1/48 ;O) It's possible though, by changing the shutter angle, as opposed to the shutter speed, you'll get a smoother look (though, again, I'm not sure how...lol). I am really intrigued by this "fault" in the Ex1(r) that seems to defy the theory : )