Strobing / flicker effect when panning in 24p at DVinfo.net

Simon Frances · February 11th, 2008, 01:31 AM

Someone please tell me this amount of strobing isn’t normal when shooting in progressive mode…

Link to uncompressed footage (192MB).

Link to compressed footage (19MB).

Theses were the settings: PAL, 35 mbps (VBR), 25p, 1920 x 1080. Shutter 1/50, manual iris, gain -3, manual white balance and manual focus.

This is my third camera, the first had the light fall-off problem (aka vignetting), the second had a focus problem and this the third, seems to have this strobing problem, although I did notice the same strobing on the second camera also.

I used to have a Canon A1 and never experience this problem shooting progressive.

Any help would be appreciated.

Regards,

Simon

Wolfgang Winne · February 11th, 2008, 02:08 AM

<Theses were the settings: PAL, 35 mbps (VBR), 25p>

this is normal in progressive mode….... I have the EX1 and the XHA1 (PAL).

Simon Frances · February 11th, 2008, 07:45 AM

All are from B&H, I didn't want the first one sent to Sony, as some people were getting there cameras back and still experiencing the same problem. I spoke to sony regarding the second one and sent them the footage; they agreed the camera was faulty but they did not know what the fault was even after it to their head engineer. So it was a case of either sending it back to Sony with no estimation of how long it was going to take or an exchange again. There seemed to be so much wrong, I opted for the later.

Quote:

Originally Posted by Wolfgang Winne

<Theses were the settings: PAL, 35 mbps (VBR), 25p>

this is normal in progressive mode….... I have the EX1 and the XHA1 (PAL).

Hi Wolfgang,

I too had the PAL version of the XHA1 but it didn't have this strobing effect like this. This has to be clearly unacceptable, it unwatchable.

So are we saying we can't use progressive with anything that moves in this fashion?

Regards,

Simon

Ola Christoffersson · February 11th, 2008, 03:33 PM

I have only watched the compressed material. Am downloading the uncompressed right now. The footage on the web had a lot of irregular strobing but this should be expected watching something filmed at 25 fps on a 60 Hz computer monitor. Are you saying that it is also strobing in an irregular way on a 50 Hz monitor?

Dennis Schmitz · February 11th, 2008, 03:48 PM

This seems to be a judder problem, or I'm totally wrong.
Don't know why this happens with your camera though.

Tried a factory reset?

regards Dennis

Christopher Witz · February 11th, 2008, 04:10 PM

wow... I have not seen anything like that from mine....

you sure it's the camera and not a software problem? almost reminds me of cineframe from the z1/fx1.... like it's a pull down issue.

your not going from 25p to 24p on export are you?

Dennis Schmitz · February 11th, 2008, 04:13 PM

So, I've watched your uncompressed material with zoomplayer (vlc shows a similar problem).

Seems ok!

Michael H. Stevens · February 11th, 2008, 09:08 PM

Simon: For various minor reasons I was thinking of asking B&H to exchange my camera but I didn't know how to approach it. How did you get them to change your camera 3 times?

Simon Frances · February 12th, 2008, 08:17 AM

Quote:

Are you saying that it is also strobing in an irregular way on a 50 Hz monitor?

I haven’t had chance to view it on a proper monitor, I was initially concerned that I could not view it on a computer monitor. I will hook it up when I return home on Wednesday.

Quote:

Tried a factory reset?

It seems to play okay in the camera, which I guess suggest the camera is fine. However it’s hard to really tell being that the LCD is a bit too small to see this.

Quote:

you sure it's the camera and not a software problem?

your not going from 25p to 24p on export are you?

I think you’re right; it seems to be a software issue. As for exporting from 25p to 24p; no, as I’m not exporting when just viewing in XDCAM Transfer and Clip Browser.

Thanks for everyones help and comments, please keep them coming. I'm also speaking to Sony to see what they can come up with.

Regards,

Simon

Ola Christoffersson · February 12th, 2008, 09:02 AM

To me it sounds like you are just experiencing what happens when you playback on a monitor with a frame rate that is not equal to or double the recording frame rate.
I would not bother Sony with this before looking at the material on a 50 Hz monitor.
Another way would be to make another recording in 30P och 60i and playback on a computer monitor. That should not produce the jitter/strobe problems.

Jack Zhang · May 18th, 2008, 11:04 PM

Just a wild guess but... um... Rolling Shutter?

Remember that those films did it on Global Shutter CCDs, not rolling shutter CMOSs.

Mike Stevens · May 18th, 2008, 11:36 PM

I understand your issue, I have same and when zooming but your pans are way too fast. As a film student you should know the MPEG suggestion is that an object in the image should take at least seven seconds to cross the screen - yours took about two. Do the test again adding zooms with slower speed and lets see what you get.

Dennis Joseph · May 19th, 2008, 08:15 AM

Wacth any hollywood action movie and you will see any speed pan to be better that what we are seeing here. From 1 second to 14 seconds.

There is just too much judder. Yesterday I did some shooting out in the forest and I had the camera focused on the character with the trees behind him. The camera was on a shoulder mount but I was not even moving it and I saw some judder when I followed the character as he walked slowly from left to right.

Even very slow movement gives a wierd looking flicker/judder effect. I'm surprised more people have not brought up this issue as much as the backfocus issue. To me, this is more annoying than the backfocus problem.

Mike Stevens · May 19th, 2008, 09:58 AM

I raised this issue back in Feb and it's like nobody understood what I meant. Try panning a line of verticle posts (like a line of tall straight trees) and see what you get. Ugh! Try zooming in 24p and you will see the center where rolling shutter has no issues is still while the further you get to the outside of the frame where lateral motion increases it pulstaes and flickers. For me zooming and fast panning just are not on with this camera.

Eric Pascarelli · May 19th, 2008, 10:06 AM

Quote:

Originally Posted by Dennis Joseph

I'm surprised more people have not brought up this issue as much as the backfocus issue. To me, this is more annoying than the backfocus problem.

The reason it has not been brought up is because this issue is not unique to the EX1. Try a side by side with another camera at the same settings and you will see.

The notion that the EX1 "renders motion" differently from other cameras (aside from the known issue of how the rolling shutter works) is a canard.

February 11th, 2008, 01:31 AM	#1
Simon Frances Regular Crew Join Date: Aug 2007 Location: London, UK Posts: 58	Strobing / flicker effect when panning in 24p Someone please tell me this amount of strobing isn’t normal when shooting in progressive mode… Link to uncompressed footage (192MB). Link to compressed footage (19MB). Theses were the settings: PAL, 35 mbps (VBR), 25p, 1920 x 1080. Shutter 1/50, manual iris, gain -3, manual white balance and manual focus. This is my third camera, the first had the light fall-off problem (aka vignetting), the second had a focus problem and this the third, seems to have this strobing problem, although I did notice the same strobing on the second camera also. I used to have a Canon A1 and never experience this problem shooting progressive. Any help would be appreciated. Regards, Simon Last edited by Simon Frances; February 11th, 2008 at 12:05 PM.

February 11th, 2008, 02:08 AM	#2
Wolfgang Winne Regular Crew Join Date: Nov 2005 Location: Bremen, Germany Posts: 176	<Theses were the settings: PAL, 35 mbps (VBR), 25p> this is normal in progressive mode….... I have the EX1 and the XHA1 (PAL). __________________ Wolfgang Winne www.ohrwurmaudio.de www.fxsupport.de

February 11th, 2008, 03:33 PM	#4
Ola Christoffersson Major Player Join Date: Nov 2007 Location: Stockholm, Sweden Posts: 462	I have only watched the compressed material. Am downloading the uncompressed right now. The footage on the web had a lot of irregular strobing but this should be expected watching something filmed at 25 fps on a 60 Hz computer monitor. Are you saying that it is also strobing in an irregular way on a 50 Hz monitor?

February 11th, 2008, 03:48 PM	#5
Dennis Schmitz Regular Crew Join Date: Dec 2007 Location: Viersen, Germany Posts: 120	This seems to be a judder problem, or I'm totally wrong. Don't know why this happens with your camera though. Tried a factory reset? regards Dennis

February 11th, 2008, 04:10 PM	#6
Christopher Witz Major Player Join Date: Feb 2006 Location: Louisville, KY Posts: 591	wow... I have not seen anything like that from mine.... you sure it's the camera and not a software problem? almost reminds me of cineframe from the z1/fx1.... like it's a pull down issue. your not going from 25p to 24p on export are you?

February 11th, 2008, 04:13 PM	#7
Dennis Schmitz Regular Crew Join Date: Dec 2007 Location: Viersen, Germany Posts: 120	So, I've watched your uncompressed material with zoomplayer (vlc shows a similar problem). Seems ok!

February 11th, 2008, 09:08 PM	#8
Michael H. Stevens Major Player Join Date: Sep 2007 Location: Palm Desert, California Posts: 311	Simon: For various minor reasons I was thinking of asking B&H to exchange my camera but I didn't know how to approach it. How did you get them to change your camera 3 times?

February 12th, 2008, 09:02 AM	#10
Ola Christoffersson Major Player Join Date: Nov 2007 Location: Stockholm, Sweden Posts: 462	To me it sounds like you are just experiencing what happens when you playback on a monitor with a frame rate that is not equal to or double the recording frame rate. I would not bother Sony with this before looking at the material on a 50 Hz monitor. Another way would be to make another recording in 30P och 60i and playback on a computer monitor. That should not produce the jitter/strobe problems.

May 18th, 2008, 11:04 PM	#11
Jack Zhang Inner Circle Join Date: May 2005 Location: Burnaby, BC, Canada Posts: 3,053	Just a wild guess but... um... Rolling Shutter? Remember that those films did it on Global Shutter CCDs, not rolling shutter CMOSs.

May 18th, 2008, 11:36 PM	#12
Mike Stevens Regular Crew Join Date: Dec 2005 Posts: 75	I understand your issue, I have same and when zooming but your pans are way too fast. As a film student you should know the MPEG suggestion is that an object in the image should take at least seven seconds to cross the screen - yours took about two. Do the test again adding zooms with slower speed and lets see what you get.

May 19th, 2008, 08:15 AM	#13
Dennis Joseph Major Player Join Date: Jan 2008 Location: Chicago, IL Posts: 206	Wacth any hollywood action movie and you will see any speed pan to be better that what we are seeing here. From 1 second to 14 seconds. There is just too much judder. Yesterday I did some shooting out in the forest and I had the camera focused on the character with the trees behind him. The camera was on a shoulder mount but I was not even moving it and I saw some judder when I followed the character as he walked slowly from left to right. Even very slow movement gives a wierd looking flicker/judder effect. I'm surprised more people have not brought up this issue as much as the backfocus issue. To me, this is more annoying than the backfocus problem.

May 19th, 2008, 09:58 AM	#14
Mike Stevens Regular Crew Join Date: Dec 2005 Posts: 75	I raised this issue back in Feb and it's like nobody understood what I meant. Try panning a line of verticle posts (like a line of tall straight trees) and see what you get. Ugh! Try zooming in 24p and you will see the center where rolling shutter has no issues is still while the further you get to the outside of the frame where lateral motion increases it pulstaes and flickers. For me zooming and fast panning just are not on with this camera.