30i or 60i ? at DVinfo.net

Rich Wells · January 25th, 2008, 12:24 AM

Somehow I missed this in my training. Should I shoot at 30i fps or 60i fps on the Sony vx2000?
And If I am using 2 cameras on a project, the Sony and a DVX, should the Sony be at 30i and the DVX at 60i ?

Adam Gold · January 25th, 2008, 02:21 PM

There is no 30i mode. It's either 60 interlaced FIELDS or 30 interlaced FRAMES. All regular DV is 30fps, as in frames.

There's a 15p but it's useless.

Shoot everything at 60i.

Rich Wells · January 25th, 2008, 03:35 PM

..but what I am referring to is the shutter speed. The Sony allows these speeds: 1/4 sec, 1/8, 1/15, 1/30, 1/60, etc up to 1/ 90, 100,125, 180, 250, 350,500,725, 1000, 1500, 2000, all the way up to 1/10000.

Which one do I use normally? 1/30 or 1/60 or what?

Thanks.

Adam Gold · January 25th, 2008, 03:43 PM

Sorry, didn't understand that's what you were asking. Shutter speed and frame rate are two different things, and neither are the same as the recording mode (i/p, 30p vs 60i, etc.)

Always use 1/60. Slower will give you more motion blur and faster will be more "stroby." That's fine if that's what you want but trying to match two cams with different shutter speeds will be a nightmare.

Dave Dodds · January 25th, 2008, 03:56 PM

It depends on the look you're going for. I find the 1/30 shutter on my PD170 to be quite pleasing for many of the things that I produce myself. There's something different about it - in a good way. It gives a feeling of "not just regular video." That said, it apparently causes a reduction in resolution. I haven't noticed anything unpleasant when watching footage shot 1/30, but the loss of resolution has scared me into shooting regular 1/60 for most "for hire" shooting gigs I do. I'm a wuss.

Anyway, shoot some tests and see which you like better.

Good luck.

~~Dave

PS When mixing the DVX with the VX, I suggest shooting 60i on the DVX with a 1/60 shutter. Set the VX to 1/60. With appropriate white balance, you should be set and have nicely matching footage between the cams.

Rich Wells · January 25th, 2008, 06:04 PM

I am clear now on the difference between shutter speed and frame rate. Good. And I understand the diff between interlaced and progressive, but do these differ from "the recording mode (i/p, 30p vs 60i, etc.)" ?

Adam Gold · January 27th, 2008, 12:18 PM

It's an imprecise term, but recording mode usually refers to the combination of frame rate, lines of resolution and whether it is i or p.

Tom Hardwick · March 3rd, 2008, 01:46 AM

Whenever you drop below the default shutter speed (1/60th sec in your NTSC case) you halve the vertical resolution at a stroke. It's an ok deal when you must have static shots of buildings at night, because the resolution loss and motion blur is often preferable to the grain of gain-up I find.

tom.

J. Stephen McDonald · March 3rd, 2008, 08:17 PM

In the past, I'd often used faster shutter speeds, such as 1/250 or 1/500, when shooting sports or even wildlife, thinking it would give me sharper images. However, the subjects, especially the wings of flying birds, often showed fluttering or strobing effects, that made them seem to be in 3 different positions at once. The different frequencies of the wing beats and the frame rate, caught the wings in out-of-sequence positions. Since the short shutter time produced sharp images of the wings at these scattered positions, your eyes would register about 3 of them at any moment. Now, I always use normal or 1/60 shutter for them. This causes the motion blur that is inherent in human vision. Each frame shows wings blurred over a long part of the stroke. This eliminates the strobing of the wings and they look much the same as we'd see them naturally. Unless you're using a higher shutter speed to open the aperture and reduce the depth-of-focus, there isn't much point in using anything but 1/60. You can accomplish this with an ND filter, instead. If you intended to make still-captures from video later, high shutter speeds would be helpful, but since vid-caps generally look pretty poor anyway, I wouldn't ruin the video for regular viewing with higher than about 1/100 shutter. A news cameraman from a local station told me that they have all their camcorders rigged, so they can't be switched or automatically shifted to anything above 1/60.

Matt Helme · May 19th, 2008, 12:46 PM

I always shoot 30 interlace. It has a very good slow and almost Film like look.

Matt

http://groups.yahoo.com/groups/newjerseydocs

Tom Hardwick · May 20th, 2008, 01:10 AM

Stephen: beautifully put, and spot on. Another thing - upping the shutter speed on CCD cameras takes you deeper into CCD smear territory, so that's another reason to stay clear.

John Cline · May 20th, 2008, 04:08 AM

Quote:

Originally Posted by Matt Helme

I always shoot 30 interlace. It has a very good slow and almost Film like look.

As Adam pointed out above, there is no such thing as 30 interlace.

January 25th, 2008, 12:24 AM	#1
Rich Wells Regular Crew Join Date: Apr 2006 Location: oakland Posts: 27	30i or 60i ? Somehow I missed this in my training. Should I shoot at 30i fps or 60i fps on the Sony vx2000? And If I am using 2 cameras on a project, the Sony and a DVX, should the Sony be at 30i and the DVX at 60i ?

January 25th, 2008, 03:35 PM	#3
Rich Wells Regular Crew Join Date: Apr 2006 Location: oakland Posts: 27	Maybe I'm thinking about this wrong... ..but what I am referring to is the shutter speed. The Sony allows these speeds: 1/4 sec, 1/8, 1/15, 1/30, 1/60, etc up to 1/ 90, 100,125, 180, 250, 350,500,725, 1000, 1500, 2000, all the way up to 1/10000. Which one do I use normally? 1/30 or 1/60 or what? Thanks.

January 25th, 2008, 06:04 PM	#6
Rich Wells Regular Crew Join Date: Apr 2006 Location: oakland Posts: 27	one more thing.. I am clear now on the difference between shutter speed and frame rate. Good. And I understand the diff between interlaced and progressive, but do these differ from "the recording mode (i/p, 30p vs 60i, etc.)" ?

March 3rd, 2008, 08:17 PM	#9
J. Stephen McDonald Major Player Join Date: Oct 2004 Location: Eugene, Oregon Posts: 909	Shutter Speed for Fast-Moving Subjects In the past, I'd often used faster shutter speeds, such as 1/250 or 1/500, when shooting sports or even wildlife, thinking it would give me sharper images. However, the subjects, especially the wings of flying birds, often showed fluttering or strobing effects, that made them seem to be in 3 different positions at once. The different frequencies of the wing beats and the frame rate, caught the wings in out-of-sequence positions. Since the short shutter time produced sharp images of the wings at these scattered positions, your eyes would register about 3 of them at any moment. Now, I always use normal or 1/60 shutter for them. This causes the motion blur that is inherent in human vision. Each frame shows wings blurred over a long part of the stroke. This eliminates the strobing of the wings and they look much the same as we'd see them naturally. Unless you're using a higher shutter speed to open the aperture and reduce the depth-of-focus, there isn't much point in using anything but 1/60. You can accomplish this with an ND filter, instead. If you intended to make still-captures from video later, high shutter speeds would be helpful, but since vid-caps generally look pretty poor anyway, I wouldn't ruin the video for regular viewing with higher than about 1/100 shutter. A news cameraman from a local station told me that they have all their camcorders rigged, so they can't be switched or automatically shifted to anything above 1/60. __________________ Steve McDonald https://onedrive.com/?cid=229807ce52dd4fe0 http://www.flickr.com/photos/22121562@N00/ http://www.vimeo.com/user458315/videos

May 19th, 2008, 12:46 PM	#10
Matt Helme New Boot Join Date: Aug 2005 Location: South Amboy New Jersey Posts: 22	30 I or 60 I I always shoot 30 interlace. It has a very good slow and almost Film like look. Matt http://groups.yahoo.com/groups/newjerseydocs

January 25th, 2008, 02:21 PM	#2
Adam Gold Inner Circle Join Date: Jan 2007 Location: Woodinville, WA USA Posts: 3,467	There is no 30i mode. It's either 60 interlaced FIELDS or 30 interlaced FRAMES. All regular DV is 30fps, as in frames. There's a 15p but it's useless. Shoot everything at 60i.

January 25th, 2008, 03:43 PM	#4
Adam Gold Inner Circle Join Date: Jan 2007 Location: Woodinville, WA USA Posts: 3,467	Sorry, didn't understand that's what you were asking. Shutter speed and frame rate are two different things, and neither are the same as the recording mode (i/p, 30p vs 60i, etc.) Always use 1/60. Slower will give you more motion blur and faster will be more "stroby." That's fine if that's what you want but trying to match two cams with different shutter speeds will be a nightmare.

January 25th, 2008, 03:56 PM	#5
Dave Dodds Major Player Join Date: Apr 2006 Location: New York Posts: 204	It depends on the look you're going for. I find the 1/30 shutter on my PD170 to be quite pleasing for many of the things that I produce myself. There's something different about it - in a good way. It gives a feeling of "not just regular video." That said, it apparently causes a reduction in resolution. I haven't noticed anything unpleasant when watching footage shot 1/30, but the loss of resolution has scared me into shooting regular 1/60 for most "for hire" shooting gigs I do. I'm a wuss. Anyway, shoot some tests and see which you like better. Good luck. ~~Dave PS When mixing the DVX with the VX, I suggest shooting 60i on the DVX with a 1/60 shutter. Set the VX to 1/60. With appropriate white balance, you should be set and have nicely matching footage between the cams.

January 27th, 2008, 12:18 PM	#7
Adam Gold Inner Circle Join Date: Jan 2007 Location: Woodinville, WA USA Posts: 3,467	It's an imprecise term, but recording mode usually refers to the combination of frame rate, lines of resolution and whether it is i or p.

March 3rd, 2008, 01:46 AM	#8
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	Whenever you drop below the default shutter speed (1/60th sec in your NTSC case) you halve the vertical resolution at a stroke. It's an ok deal when you must have static shots of buildings at night, because the resolution loss and motion blur is often preferable to the grain of gain-up I find. tom.

May 20th, 2008, 01:10 AM	#11
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	Stephen: beautifully put, and spot on. Another thing - upping the shutter speed on CCD cameras takes you deeper into CCD smear territory, so that's another reason to stay clear.