HV20 25p 1/25 shutter: loss of detail or not? at DVinfo.net

Reese Leysen · July 25th, 2007, 12:37 PM

I was just wondering if anyone could tell me if there would be a loss of detail when shooting at 25p 1/25 shutter with the HV20.

For as far as I know, there's resolution loss with all dv cams when shooting interlaced 50i/60i at lower than 1/50 or 1/60 shutter, but is the resolution also affected when shooting 25p?

Thanks!

Pieter Jongerius · July 25th, 2007, 12:55 PM

my $.02
I really don't see how this could be true, as long as you hold the camera still and motion blur is not an issue. Even for interlaced shooting. What's your guess on this? Because I think:

Focus? Not affected.
Iris(DOF)? Open most of the time anyway.
CMOS pixel charge bleed at high exposure times? Nah...

Pieter

Enea Lanzarone · July 25th, 2007, 01:14 PM

According to Wolfgang Winne's website and his extensive testing of the HV20, there is a resolution loss when shooting with a shutter speed of 1/25.

Have a look at these full resolution stills (frame grabs) from his page (he used a infrared blocking filter on these, but on both picture examples, so that doesn't make a difference):

This was shot in P mode at 1/50:
http://www.fxsupport.de/pic/07/06/10/09.jpg

This was shot at 1/25:
http://www.fxsupport.de/pic/07/06/10/10.jpg
(Have a close look at the resolution test pattern and the edges)

I can see the difference, but it's not bad IMHO...it was much worse on my first Sony Hi8 cam (even though I shot a lot at 1/25, as I loved the "look").

Reese Leysen · July 25th, 2007, 02:13 PM

Quote:

Originally Posted by Enea Lanzarone

According to Wolfgang Winne's website and his extensive testing of the HV20, there is a resolution loss when shooting with a shutter speed of 1/25.

Have a look at these full resolution stills (frame grabs) from his page (he used a infrared blocking filter on these, but on both picture examples, so that doesn't make a difference):

This was shot in P mode at 1/50:
http://www.fxsupport.de/pic/07/06/10/09.jpg

This was shot at 1/25:
http://www.fxsupport.de/pic/07/06/10/10.jpg
(Have a close look at the resolution test pattern and the edges)

I can see the difference, but it's not bad IMHO...it was much worse on my first Sony Hi8 cam (even though I shot a lot at 1/25, as I loved the "look").

Oh, if that's all, then I can definitely live with that, it's probably less loss of detail than even 1.5db of gain so it surely beats adding gain to get more light instead of lowering shutter.

Pieter Jongerius · July 28th, 2007, 01:41 PM

Hi Enea,

thanks for those shots. I also went to Wolfgangs site (eventuall found it all at http://www.fxsupport.de/22.html).
Vertical resolution is indeed messed up big time, always a risk in interlaced situations. Seems to be a processing problem either in-cam or in the creation of these shots. Because of the thoroughness of Wolfgang I suspect its really in-cam. :(
Almost seems like only one of the flields is used and interpolated. Whatever it is that is doing that to the fields, you shouldnt have it in 'p'-mode. And Wolfgang actually has a shot in 25p, although he doesn't specify shutter: http://www.fxsupport.de/pic/07/06/10/21.jpg. Better.

Pieter

Luc Fender · July 28th, 2007, 03:38 PM

Even more interesting was his last page about a mic solution:

http://www.fxsupport.de/23.html

Seems to work pretty well but it isn't clear to me if this is a custom solution or not and if this is also available in the US.

July 25th, 2007, 12:37 PM	#1
Reese Leysen Regular Crew Join Date: Feb 2007 Location: Belgium Posts: 114	HV20 25p 1/25 shutter: loss of detail or not? I was just wondering if anyone could tell me if there would be a loss of detail when shooting at 25p 1/25 shutter with the HV20. For as far as I know, there's resolution loss with all dv cams when shooting interlaced 50i/60i at lower than 1/50 or 1/60 shutter, but is the resolution also affected when shooting 25p? Thanks!

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July 25th, 2007, 12:55 PM	#2
Pieter Jongerius Regular Crew Join Date: Jan 2007 Location: Netherlands Posts: 101	my $.02 I really don't see how this could be true, as long as you hold the camera still and motion blur is not an issue. Even for interlaced shooting. What's your guess on this? Because I think: Focus? Not affected. Iris(DOF)? Open most of the time anyway. CMOS pixel charge bleed at high exposure times? Nah... Pieter

July 25th, 2007, 01:14 PM	#3
Enea Lanzarone Regular Crew Join Date: Mar 2007 Location: Switzerland Posts: 53	According to Wolfgang Winne's website and his extensive testing of the HV20, there is a resolution loss when shooting with a shutter speed of 1/25. Have a look at these full resolution stills (frame grabs) from his page (he used a infrared blocking filter on these, but on both picture examples, so that doesn't make a difference): This was shot in P mode at 1/50: http://www.fxsupport.de/pic/07/06/10/09.jpg This was shot at 1/25: http://www.fxsupport.de/pic/07/06/10/10.jpg (Have a close look at the resolution test pattern and the edges) I can see the difference, but it's not bad IMHO...it was much worse on my first Sony Hi8 cam (even though I shot a lot at 1/25, as I loved the "look").

July 28th, 2007, 01:41 PM	#5
Pieter Jongerius Regular Crew Join Date: Jan 2007 Location: Netherlands Posts: 101	Hi Enea, thanks for those shots. I also went to Wolfgangs site (eventuall found it all at http://www.fxsupport.de/22.html). Vertical resolution is indeed messed up big time, always a risk in interlaced situations. Seems to be a processing problem either in-cam or in the creation of these shots. Because of the thoroughness of Wolfgang I suspect its really in-cam. :( Almost seems like only one of the flields is used and interpolated. Whatever it is that is doing that to the fields, you shouldnt have it in 'p'-mode. And Wolfgang actually has a shot in 25p, although he doesn't specify shutter: http://www.fxsupport.de/pic/07/06/10/21.jpg. Better. Pieter

July 28th, 2007, 03:38 PM	#6
Luc Fender Regular Crew Join Date: Apr 2007 Location: Seattle, WA Posts: 61	Even more interesting was his last page about a mic solution: http://www.fxsupport.de/23.html Seems to work pretty well but it isn't clear to me if this is a custom solution or not and if this is also available in the US.