1/25th shutter speed = half resolution? at DVinfo.net

Asa Phelps · November 17th, 2004, 09:10 AM

Shooting at 1/25th shutter speed on 25p PAL will give more motion blur BUT will cut the resolution?

TIA,
Asa

Marty Hudzik · November 17th, 2004, 09:24 AM

<<<-- Originally posted by Asa Phelps : Shooting at 1/25th shutter speed on 25p PAL will give more motion blur BUT will cut the resolution?

TIA,
Asa -->>>

It should not cut the resolution. In theory. Unless Canon did something "whack" here it should still be full resolution.

Mathieu Ghekiere · November 17th, 2004, 09:25 AM

I don't think so.
Are you asking if you film at a 1/25th shutter speed you loose half of your resolution? No, I'm actually pretty sure that isn't so.

Lauri Kettunen · November 17th, 2004, 09:27 AM

You mean, the spatial resolution depended on the shutter speed? If so, this is not the case. The spatial resolution is constant for all shutter speeds. But as you say, longer shutter speed imply the objects in motion appear less sharp.

Rob Lohman · November 17th, 2004, 09:32 AM

Welcome aboard DVInfo.net Asa!

Asa Phelps · November 17th, 2004, 09:43 AM

Thanks,
I remember that with XL1 has been said shooting at 1/25th would have cut in half the resolution..
Maybe was just the blurring effect of the slow shutter that made objects appear less sharp

Asa

Andre De Clercq · November 17th, 2004, 10:36 AM

Indeed Asa, besides motion blurr (when there is motion in the pic) in 1/25 (1/30) mode and lower, your cam just outputs only one of the two fields. the field is being repeated to form an interlaced frame. So you get only get 50% vertical resolution.

David Lach · November 17th, 2004, 04:08 PM

Asa, maybe you mean (or you've heard) shooting in the frame mode (fake 25p), which on the XL1 meant losing resolution. But 25p on the XL2 is true progressive, meaning you won't lose any resolution. The XL2 uses true progressive scan CCDs, not the XL1.

Barry Green · November 17th, 2004, 04:59 PM

On the PD150 and other interlaced cameras, yes using a slower-than-field-rate shutter speed would cut the resolution in half.

On the DVX (and presumably the XL2) you still keep full resolution, even as low as 1/6 of a second.

Andre De Clercq · November 17th, 2004, 05:17 PM

Could well be indeed that cams which have proscan mode also keep their resolution in slower- than-FIELD-rate shutterspeeds

Barry Green · November 17th, 2004, 08:51 PM

Right -- sorry for the wrong word, I changed it to avoid confusion.

November 17th, 2004, 09:10 AM	#1
Asa Phelps New Boot Join Date: Sep 2004 Location: Venice, Italy Posts: 23	1/25th shutter speed = half resolution? Shooting at 1/25th shutter speed on 25p PAL will give more motion blur BUT will cut the resolution? TIA, Asa

November 17th, 2004, 09:24 AM	#2
Marty Hudzik Trustee Join Date: Jul 2004 Location: Canton, Ohio Posts: 1,771	Re: 1/25th shutter speed = half resolution? <<<-- Originally posted by Asa Phelps : Shooting at 1/25th shutter speed on 25p PAL will give more motion blur BUT will cut the resolution? TIA, Asa -->>> It should not cut the resolution. In theory. Unless Canon did something "whack" here it should still be full resolution.

November 17th, 2004, 09:32 AM	#5
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	Welcome aboard DVInfo.net Asa! __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

November 17th, 2004, 09:25 AM	#3
Mathieu Ghekiere Inner Circle Join Date: Jun 2004 Location: Belgium Posts: 2,195	I don't think so. Are you asking if you film at a 1/25th shutter speed you loose half of your resolution? No, I'm actually pretty sure that isn't so.

November 17th, 2004, 09:27 AM	#4
Lauri Kettunen Major Player Join Date: Aug 2004 Location: Kangasala, Finland Posts: 445	You mean, the spatial resolution depended on the shutter speed? If so, this is not the case. The spatial resolution is constant for all shutter speeds. But as you say, longer shutter speed imply the objects in motion appear less sharp.

November 17th, 2004, 09:43 AM	#6
Asa Phelps New Boot Join Date: Sep 2004 Location: Venice, Italy Posts: 23	Thanks, I remember that with XL1 has been said shooting at 1/25th would have cut in half the resolution.. Maybe was just the blurring effect of the slow shutter that made objects appear less sharp Asa

November 17th, 2004, 10:36 AM	#7
Andre De Clercq Major Player Join Date: Sep 2002 Location: Belgium Posts: 804	Indeed Asa, besides motion blurr (when there is motion in the pic) in 1/25 (1/30) mode and lower, your cam just outputs only one of the two fields. the field is being repeated to form an interlaced frame. So you get only get 50% vertical resolution.

November 17th, 2004, 04:08 PM	#8
David Lach Major Player Join Date: Oct 2002 Location: Montreal, QC, Canada Posts: 570	Asa, maybe you mean (or you've heard) shooting in the frame mode (fake 25p), which on the XL1 meant losing resolution. But 25p on the XL2 is true progressive, meaning you won't lose any resolution. The XL2 uses true progressive scan CCDs, not the XL1.

November 17th, 2004, 04:59 PM	#9
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	On the PD150 and other interlaced cameras, yes using a slower-than-field-rate shutter speed would cut the resolution in half. On the DVX (and presumably the XL2) you still keep full resolution, even as low as 1/6 of a second.

November 17th, 2004, 05:17 PM	#10
Andre De Clercq Major Player Join Date: Sep 2002 Location: Belgium Posts: 804	Could well be indeed that cams which have proscan mode also keep their resolution in slower- than-FIELD-rate shutterspeeds

November 17th, 2004, 08:51 PM	#11
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	Right -- sorry for the wrong word, I changed it to avoid confusion.