Shutter speed 25 at DVinfo.net

Betsy Moore · March 12th, 2006, 02:57 AM

I know that shooting with a shutter speed of 25 (I have the FX1-e) is not recommended if you want to transfer to film but... I love the film look of shooting at that shutter speed and I hate losing all the resolution you lose when shooting at their faux progressive 24p mode and also hate losing all the resolution in apple post programs that convert it to 24p. My question is... do you lose resolution when shooting at shutter speed of 25--and are there any editing difficulties when shooting at shutter speed 25? None of Sony manuals give you a straight answer. Thanks a ton if ya' know:)

Ainslie Davies · March 12th, 2006, 04:03 AM

Problems; 1) The motion looks terrible at 1/25. 2) The image is still interlaced not progressive, this is where the slight loss of resolution goes if you convert to 25/24p in post 3) Effects that you want to do in post may look worse, especially any slow motion 4) Strobing lights?, strobing transfers from dark to light places? More pronounced artifacts/dropouts?

Personally, I love 24/25p video but putting a 1/25th shutter speed on a interlaced image just causes me a headache, you may like it, and If you have experimented with different shutter speeds or deinterlacing techniques and like this the best then ultimately its your taste. It may be a signature effect :-)

I shoot at 50i, keep it in a 1080interlaced timeline to render and render out a pristine 50i version, a 25p and 24p version to cover different distribution formats and prepping for film.

__________________
www.inasinglemoment.com - Everything can change, Duality's premiere feature film.

Boyd Ostroff · March 12th, 2006, 07:20 AM

I believe that if you shoot at 1/25 sec the effect is acheived by "field doubling" which means the same data is written to both interlaced fields. This would theoretically cause a 50% vertical resolution loss in HDV mode. However if you're downconverting to standard definition, or shooting in DV mode, there wouldn't be a noticeable resolution loss.

I thought the PAL FX1 had cf25 and not cf24 (my Z1 has cf24, cf25 and cf30)? Maybe that would be a better option, although I think you also lose some resolution in that mode. See the following:

http://www.adamwilt.com/HDV/cineframe.html

Dylan Pank · March 12th, 2006, 09:01 AM

The loss in resolution in CF25 is identical to the loss in 25/s shutter - they both work by field doubling. There's no resolution advatnage to shooting in 25/s, in fact some (my self included) would find it worse becuase of the additional motion blur.

CF24 however also adds additional artifacts because it's switching between upper and lower fields to deliver the 24 frames within 30i.

Betsy Moore · March 12th, 2006, 01:12 PM

Ah, so you actually lose half your resolution in 25/s... and to convert 50i or 60i to progressive in post also results in resolution loss too--bugger...

Dylan Pank · March 13th, 2006, 02:34 PM

Well, how much res you lose depends on how you de-interlace. Some smart de-interlacing options do pretty well, but it's true that it wouldn't match the res of a true progressive scan capture - but currently no 1080 HDV cam offers that option.

March 12th, 2006, 02:57 AM	#1
Betsy Moore Major Player Join Date: Mar 2003 Location: Los Angeles Posts: 444	Shutter speed 25 I know that shooting with a shutter speed of 25 (I have the FX1-e) is not recommended if you want to transfer to film but... I love the film look of shooting at that shutter speed and I hate losing all the resolution you lose when shooting at their faux progressive 24p mode and also hate losing all the resolution in apple post programs that convert it to 24p. My question is... do you lose resolution when shooting at shutter speed of 25--and are there any editing difficulties when shooting at shutter speed 25? None of Sony manuals give you a straight answer. Thanks a ton if ya' know:)

March 12th, 2006, 04:03 AM	#2
Ainslie Davies Regular Crew Join Date: Nov 2005 Location: Auckland, New Zealand Posts: 117	Problems; 1) The motion looks terrible at 1/25. 2) The image is still interlaced not progressive, this is where the slight loss of resolution goes if you convert to 25/24p in post 3) Effects that you want to do in post may look worse, especially any slow motion 4) Strobing lights?, strobing transfers from dark to light places? More pronounced artifacts/dropouts? Personally, I love 24/25p video but putting a 1/25th shutter speed on a interlaced image just causes me a headache, you may like it, and If you have experimented with different shutter speeds or deinterlacing techniques and like this the best then ultimately its your taste. It may be a signature effect :-) I shoot at 50i, keep it in a 1080interlaced timeline to render and render out a pristine 50i version, a 25p and 24p version to cover different distribution formats and prepping for film. __________________ www.inasinglemoment.com - Everything can change, Duality's premiere feature film. __________________ Ainslie Davies - www.dualityproductions.com

March 12th, 2006, 07:20 AM	#3
Boyd Ostroff Wrangler Join Date: Dec 2002 Location: Mays Landing, NJ Posts: 11,790	I believe that if you shoot at 1/25 sec the effect is acheived by "field doubling" which means the same data is written to both interlaced fields. This would theoretically cause a 50% vertical resolution loss in HDV mode. However if you're downconverting to standard definition, or shooting in DV mode, there wouldn't be a noticeable resolution loss. I thought the PAL FX1 had cf25 and not cf24 (my Z1 has cf24, cf25 and cf30)? Maybe that would be a better option, although I think you also lose some resolution in that mode. See the following: http://www.adamwilt.com/HDV/cineframe.html

March 12th, 2006, 09:01 AM	#4
Dylan Pank Major Player Join Date: Nov 2004 Location: Portsmouth, UK Posts: 611	The loss in resolution in CF25 is identical to the loss in 25/s shutter - they both work by field doubling. There's no resolution advatnage to shooting in 25/s, in fact some (my self included) would find it worse becuase of the additional motion blur. CF24 however also adds additional artifacts because it's switching between upper and lower fields to deliver the 24 frames within 30i.

March 12th, 2006, 01:12 PM	#5
Betsy Moore Major Player Join Date: Mar 2003 Location: Los Angeles Posts: 444	Ah, so you actually lose half your resolution in 25/s... and to convert 50i or 60i to progressive in post also results in resolution loss too--bugger...

March 13th, 2006, 02:34 PM	#6
Dylan Pank Major Player Join Date: Nov 2004 Location: Portsmouth, UK Posts: 611	Well, how much res you lose depends on how you de-interlace. Some smart de-interlacing options do pretty well, but it's true that it wouldn't match the res of a true progressive scan capture - but currently no 1080 HDV cam offers that option.