Image Stabelizer? at DVinfo.net

Denny Kyser · March 6th, 2008, 07:47 PM

I know to turn this off when on a tripod, but how about when doing moving camera tracks. How about with a monopod, Do you leave this on, or turn it off.

John Moon · March 7th, 2008, 07:27 AM

If handheld I leave it on...if on Steadicam or Glidecam...off.

Nick Weeks · March 12th, 2008, 07:12 AM

Agreed... I still wish they made this mappable to a custom button. So many times I switch from handheld to something else and forget to disable this, footage turns to crap

Denny Kyser · March 12th, 2008, 07:40 AM

Quote:

Originally Posted by Nick Weeks

Agreed... I still wish they made this mappable to a custom button. So many times I switch from handheld to something else and forget to disable this, footage turns to crap

For this reason I am wondering about just leaving it off.

Denny Kyser · March 12th, 2008, 08:10 AM

How about while doing handheld moving techniques, on or off.

Nick Weeks · March 12th, 2008, 07:03 PM

I've found it better to leave it on during handheld techniques, because the smaller cameras, like the XH A1, are such light cameras, even doing basic movements introduces some shake because you don't have enough weight to counterbalance the movements. I've done similar shots on a JVC HD250 (which doesn't have any stabilization) and it comes out really well because of the added weight. It isn't that noticeable on the small FCP window, but on a big screen TV it really stands out. This is fixed when I use the stabilizer.

Now if you're doing fast moving shots (like a car racing event for example) I've noticed the stabilizer tries to compensate for the natural quick movement of your pans/zooms etc and it would have worked better to have it off.

For slow stuff, though, I leave it on

Waldemar Winkler · March 14th, 2008, 09:20 PM

Think about GOP (group of pictures) compression for a moment. It is the basis of DV video. Frame 1 digitizes the entire frame. Frames 2-15 digitize only the data values of the image that have changed from Frame 1. Usually the time value from frame one to fifteen is one-half second. Then the process starts all over again with Frame 16 actually being Frame 1 of the second GOP ... and so on. Image stabilization could significantly reduce the file sizes of GOP 2-15 ... or could produce completely unusable footage.

Image stabilization has the potential to significantly reduce the data needed to be recorded for frames 2-15 of any GOP. It won't let a lazy camera operator keep his job, but it will allow a conscientious camera person maximize usable footage from his shoot.

If the camera is locked onto a tripod, keeping image stabilization active causes issues because the camera is trying to compensate for problems that do not exist. One will get unnecessary focus movement. Turn image stabilization off when camera is locked on a tripod. In any other shooting situation, experiment with image stabilization turned on and evaluate for future reference. Image stabilization systems vary in effectiveness from camera to camera. Always test IS-on vs IS-off throughout the camera's many features.

Robert M Wright · March 14th, 2008, 09:54 PM

Quote:

Originally Posted by Waldemar Winkler

Think about GOP (group of pictures) compression for a moment. It is the basis of DV video...

I think you mean HDV? (DV uses only intraframe compression)

Peter Jefferson · March 15th, 2008, 06:25 AM

"Think about GOP (group of pictures) compression for a moment. It is the basis of DV video. "

No it isn't. it's the Basis of MPG video.
MPG2 (M2t in this case) using LongGop infastructure based on 6 frames (720p) or 12 (50i)-15 frames (60i)
It has no relation to Intraframe DV or DVCPRo/HD

" Frame 1 digitizes the entire frame. Frames 2-15 digitize only the data values of the image that have changed from Frame 1. "

Not always. When cutting outside the I frame threshold, the actual GOP resets. In some cases, some cameras/nle's cannot handle LongGop timecode properly because of this resetting of the Iframe.

" Usually the time value from frame one to fifteen is one-half second. Then the process starts all over again with Frame 16 actually being Frame 1 of the second GOP ... and so on. "

Again, in most cases, this is the case, however this again is determined by the I frame insertion point (start/stop)

With AVCHD, you're looking at a 33 frame Long Gop infrastructure. Its only saving grace is the fact that the I frame management is vastly superior to MPG2. But we're not talking about AVCHD.

"Image stabilization could significantly reduce the file sizes of GOP 2-15 ... or could produce completely unusable footage."

I am yet to have any issues using long gop handheld or on a Steadicam Pilot rig. I also don't have issues when recording as I'm running (without a stabiliser).

The fact that MPG2 M2t is 25mbps forces the file size to remain a constant. I do not know where this information arose regarding file size, however what DOES happen is that the codec itself is pushed due to the motion. Unlike Intra, MPG2 wont be as pristine, however to be perfectly honest, it won't make a difference to the human eye UNLESS your running significant shutter speeds (above and beyond 1/250th) Only then will frame differentiation will be as noticeable. As it stands, the human eye cannot discern the difference.

Its one reason I skipped DVCProHD and the HVX for weddings, as it does not offer anything substantial over the A1. For corporate, where contracts and investments are at least 3x to 6x higher in cost, then I use the appropriate tool. In any case, for weddings, I would not worry about long gop. I personally believe that this argument is moot and has been done to death. Just look at Pat's work. It's all long gop on Steadicam.

"Image stabilization has the potential to significantly reduce the data needed to be recorded for frames 2-15 of any GOP. "

Not data. The data bitstream will ALWAYS remain the same. The only difference is how the codec responds to these extreme changes of frame within that GOP structure. Theoretically you are correct and I do agree with you that Stabilisation is more efficient for the codec (colour and frame wise), but its not someone one should lose sleep over.

"It won't let a lazy camera operator keep his job"

You obviously havent seen some of the junk some of the guys down here tote around... really its extraordinarily scary!

"but it will allow a conscientious camera person maximize usable footage from his shoot."

Agreed. One thing to note is that the A1 has a character within the OIS. Once you can master the beast, you can do a lot with the OIS on to a point of being silly.

If the camera is locked onto a tripod, keeping image stabilization active causes issues because the camera is trying to compensate for problems that do not exist. One will get unnecessary focus movement. Turn image stabilization off when camera is locked on a tripod. In any other shooting situation, experiment with image stabilization turned on and evaluate for future reference. Image stabilization systems vary in effectiveness from camera to camera. Always test IS-on vs IS-off throughout the camera's many features.

March 6th, 2008, 07:47 PM	#1
Denny Kyser Major Player Join Date: Aug 2007 Location: Warren, Pa Posts: 785	Image Stabelizer? I know to turn this off when on a tripod, but how about when doing moving camera tracks. How about with a monopod, Do you leave this on, or turn it off. __________________ 2 Canon XF305's Kyser Photography www.kyserphoto.com

March 7th, 2008, 07:27 AM	#2
John Moon Major Player Join Date: Mar 2006 Location: Indianapolis, IN Posts: 446	If handheld I leave it on...if on Steadicam or Glidecam...off. __________________ John J. Moon www.northernlightfilmworks.com - Event DV Top 25 Recipient

March 12th, 2008, 08:10 AM	#5
Denny Kyser Major Player Join Date: Aug 2007 Location: Warren, Pa Posts: 785	How about while doing handheld moving techniques, on or off. __________________ 2 Canon XF305's Kyser Photography www.kyserphoto.com

March 14th, 2008, 09:20 PM	#7
Waldemar Winkler Major Player Join Date: Aug 2004 Location: Durango, Colorado, USA Posts: 711	Think about GOP (group of pictures) compression for a moment. It is the basis of DV video. Frame 1 digitizes the entire frame. Frames 2-15 digitize only the data values of the image that have changed from Frame 1. Usually the time value from frame one to fifteen is one-half second. Then the process starts all over again with Frame 16 actually being Frame 1 of the second GOP ... and so on. Image stabilization could significantly reduce the file sizes of GOP 2-15 ... or could produce completely unusable footage. Image stabilization has the potential to significantly reduce the data needed to be recorded for frames 2-15 of any GOP. It won't let a lazy camera operator keep his job, but it will allow a conscientious camera person maximize usable footage from his shoot. If the camera is locked onto a tripod, keeping image stabilization active causes issues because the camera is trying to compensate for problems that do not exist. One will get unnecessary focus movement. Turn image stabilization off when camera is locked on a tripod. In any other shooting situation, experiment with image stabilization turned on and evaluate for future reference. Image stabilization systems vary in effectiveness from camera to camera. Always test IS-on vs IS-off throughout the camera's many features. __________________ Waldemar

March 12th, 2008, 07:12 AM	#3
Nick Weeks Major Player Join Date: Jan 2006 Location: Birmingham, AL USA Posts: 722	Agreed... I still wish they made this mappable to a custom button. So many times I switch from handheld to something else and forget to disable this, footage turns to crap

March 12th, 2008, 07:03 PM	#6
Nick Weeks Major Player Join Date: Jan 2006 Location: Birmingham, AL USA Posts: 722	I've found it better to leave it on during handheld techniques, because the smaller cameras, like the XH A1, are such light cameras, even doing basic movements introduces some shake because you don't have enough weight to counterbalance the movements. I've done similar shots on a JVC HD250 (which doesn't have any stabilization) and it comes out really well because of the added weight. It isn't that noticeable on the small FCP window, but on a big screen TV it really stands out. This is fixed when I use the stabilizer. Now if you're doing fast moving shots (like a car racing event for example) I've noticed the stabilizer tries to compensate for the natural quick movement of your pans/zooms etc and it would have worked better to have it off. For slow stuff, though, I leave it on

March 15th, 2008, 06:25 AM	#9
Peter Jefferson Inner Circle Join Date: Apr 2003 Location: Aus Posts: 3,884	"Think about GOP (group of pictures) compression for a moment. It is the basis of DV video. " No it isn't. it's the Basis of MPG video. MPG2 (M2t in this case) using LongGop infastructure based on 6 frames (720p) or 12 (50i)-15 frames (60i) It has no relation to Intraframe DV or DVCPRo/HD " Frame 1 digitizes the entire frame. Frames 2-15 digitize only the data values of the image that have changed from Frame 1. " Not always. When cutting outside the I frame threshold, the actual GOP resets. In some cases, some cameras/nle's cannot handle LongGop timecode properly because of this resetting of the Iframe. " Usually the time value from frame one to fifteen is one-half second. Then the process starts all over again with Frame 16 actually being Frame 1 of the second GOP ... and so on. " Again, in most cases, this is the case, however this again is determined by the I frame insertion point (start/stop) With AVCHD, you're looking at a 33 frame Long Gop infrastructure. Its only saving grace is the fact that the I frame management is vastly superior to MPG2. But we're not talking about AVCHD. "Image stabilization could significantly reduce the file sizes of GOP 2-15 ... or could produce completely unusable footage." I am yet to have any issues using long gop handheld or on a Steadicam Pilot rig. I also don't have issues when recording as I'm running (without a stabiliser). The fact that MPG2 M2t is 25mbps forces the file size to remain a constant. I do not know where this information arose regarding file size, however what DOES happen is that the codec itself is pushed due to the motion. Unlike Intra, MPG2 wont be as pristine, however to be perfectly honest, it won't make a difference to the human eye UNLESS your running significant shutter speeds (above and beyond 1/250th) Only then will frame differentiation will be as noticeable. As it stands, the human eye cannot discern the difference. Its one reason I skipped DVCProHD and the HVX for weddings, as it does not offer anything substantial over the A1. For corporate, where contracts and investments are at least 3x to 6x higher in cost, then I use the appropriate tool. In any case, for weddings, I would not worry about long gop. I personally believe that this argument is moot and has been done to death. Just look at Pat's work. It's all long gop on Steadicam. "Image stabilization has the potential to significantly reduce the data needed to be recorded for frames 2-15 of any GOP. " Not data. The data bitstream will ALWAYS remain the same. The only difference is how the codec responds to these extreme changes of frame within that GOP structure. Theoretically you are correct and I do agree with you that Stabilisation is more efficient for the codec (colour and frame wise), but its not someone one should lose sleep over. "It won't let a lazy camera operator keep his job" You obviously havent seen some of the junk some of the guys down here tote around... really its extraordinarily scary! "but it will allow a conscientious camera person maximize usable footage from his shoot." Agreed. One thing to note is that the A1 has a character within the OIS. Once you can master the beast, you can do a lot with the OIS on to a point of being silly. If the camera is locked onto a tripod, keeping image stabilization active causes issues because the camera is trying to compensate for problems that do not exist. One will get unnecessary focus movement. Turn image stabilization off when camera is locked on a tripod. In any other shooting situation, experiment with image stabilization turned on and evaluate for future reference. Image stabilization systems vary in effectiveness from camera to camera. Always test IS-on vs IS-off throughout the camera's many features.