Angle setting vs shutter speed in interlaced mode- try this test at DVinfo.net

Federico Perale · December 14th, 2010, 12:49 PM

I feel compelled to send the link of a thread I started in the Sony Z1 forum, as I am keen to know if any EX1r user (that might have missed this) has an opinion

http://www.dvinfo.net/forum/sony-hvr...0-shutter.html

please have a look at the last posts, to see that we've noticed a strange lack of correspondence between shooting at 1/60 when in 30p and shooting with the 180 degrees setting, whereas in theory they should be equivalent (and similarly shooting at 1/50 when in 25p)

check by yourselves!

Piotr Wozniacki · December 14th, 2010, 02:07 PM

I don't find anything strange in the fact that the shutter angle notion, brought from the film domain, only really applies to progressive video.

Serena Steuart · December 17th, 2010, 06:08 PM

There is no magic about 180 deg shutter. It is, as Piotr says, an artefact of film cameras. The shutter had to be closed while the film was pulled down to the next frame, and the simplest mechanism allowed the shutter to be open for half the framing rate. The 16mm Bolex cameras (famous H16RX series) had a shutter opening of 165 deg max, and there were cameras (with accelerated pull down) that allowed more than 180 degrees). Shutter openings were adjusted to prevent flicker in lighting (between 90 and 200 deg, commonly 144 deg for 60Hz power and 24fps) and to suit action. The "film look" is not achieved by setting shutter angle. It is achieved by lighting, colour grading, and technique.
I note (in that Z1 thread) that someone said the film look (24fps) is supposed to look jerky. Not to my eye, but if you shoot with high shutter speeds (or small shutter angles) you certainly will see jerkiness in motion. If you are in PAL countries there is no sense in shooting 24 instead of 25 fps.
Not too long ago there was a thread about shooting "shutter off", where somebody enthusiastically claimed that all Hollywood features are shot 180 deg shutter on digital cameras (their eyes knew this), despite most features still being shot on film. Try shooting 25P with shutter off; I think you will be surprised by the nice results (unless you're filming sports and such like). In 60Hz countries, try 30P (motion certainly will be smoother).

Craig Seeman · December 18th, 2010, 12:04 PM

For those who are confused by all this, the intent is "motion blur." With the proper shutter speed/angle, the motion will blur and thus appear smooth, not jerky. Also at lower frame rates such as 24fps one must be more careful about camera pan rates (use slower panning) to avoid jerkiness.

Serena Steuart · December 20th, 2010, 06:15 AM

panning at 24fps, 7 seconds for a point to cross the frame. Indeed, motion blur is your friend. But we've debated this before.

December 14th, 2010, 12:49 PM	#1
Federico Perale Major Player Join Date: Apr 2010 Location: London Posts: 410	Angle setting vs shutter speed in interlaced mode- try this test I feel compelled to send the link of a thread I started in the Sony Z1 forum, as I am keen to know if any EX1r user (that might have missed this) has an opinion http://www.dvinfo.net/forum/sony-hvr...0-shutter.html please have a look at the last posts, to see that we've noticed a strange lack of correspondence between shooting at 1/60 when in 30p and shooting with the 180 degrees setting, whereas in theory they should be equivalent (and similarly shooting at 1/50 when in 25p) check by yourselves!

December 14th, 2010, 02:07 PM	#2
Piotr Wozniacki Inner Circle Join Date: Aug 2006 Location: Poland Posts: 4,086	I don't find anything strange in the fact that the shutter angle notion, brought from the film domain, only really applies to progressive video. __________________ Sony PXW-FS7 \| DaVinci Resolve Studio; Magix Vegas Pro; i7-5960X CPU; 64 GB RAM; 2x GTX 1080 8GB GPU; Decklink 4K Extreme 12G; 4x 3TB WD Black in RAID 0; 1TB M.2 NVMe cache drive

December 17th, 2010, 06:08 PM	#3
Serena Steuart Major Player Join Date: Jun 2006 Location: Studio Alnitak, Melbourne, Victoria, Australia Posts: 640 Images: 3	There is no magic about 180 deg shutter. It is, as Piotr says, an artefact of film cameras. The shutter had to be closed while the film was pulled down to the next frame, and the simplest mechanism allowed the shutter to be open for half the framing rate. The 16mm Bolex cameras (famous H16RX series) had a shutter opening of 165 deg max, and there were cameras (with accelerated pull down) that allowed more than 180 degrees). Shutter openings were adjusted to prevent flicker in lighting (between 90 and 200 deg, commonly 144 deg for 60Hz power and 24fps) and to suit action. The "film look" is not achieved by setting shutter angle. It is achieved by lighting, colour grading, and technique. I note (in that Z1 thread) that someone said the film look (24fps) is supposed to look jerky. Not to my eye, but if you shoot with high shutter speeds (or small shutter angles) you certainly will see jerkiness in motion. If you are in PAL countries there is no sense in shooting 24 instead of 25 fps. Not too long ago there was a thread about shooting "shutter off", where somebody enthusiastically claimed that all Hollywood features are shot 180 deg shutter on digital cameras (their eyes knew this), despite most features still being shot on film. Try shooting 25P with shutter off; I think you will be surprised by the nice results (unless you're filming sports and such like). In 60Hz countries, try 30P (motion certainly will be smoother).

December 18th, 2010, 12:04 PM	#4
Craig Seeman Inner Circle Join Date: Feb 2004 Location: Brooklyn, NY, USA Posts: 3,841	For those who are confused by all this, the intent is "motion blur." With the proper shutter speed/angle, the motion will blur and thus appear smooth, not jerky. Also at lower frame rates such as 24fps one must be more careful about camera pan rates (use slower panning) to avoid jerkiness.

December 20th, 2010, 06:15 AM	#5
Serena Steuart Major Player Join Date: Jun 2006 Location: Studio Alnitak, Melbourne, Victoria, Australia Posts: 640 Images: 3	panning at 24fps, 7 seconds for a point to cross the frame. Indeed, motion blur is your friend. But we've debated this before.