HC7 rolling shutter & match-moving at DVinfo.net

Jack Kelly · June 21st, 2007, 04:34 AM

Hi there,

Does the HC7 have a rolling shutter like the HV20? I ask because I'm keen to buy a cheap HDV camera that I can (occasionally) use for capturing footage for match-moving using SynthEyes. The HV20 has a rolling shutter which causes match-moving-killing distortions.

Thanks,
Jack

Jack Zhang · June 21st, 2007, 04:57 AM

Unfortunately, all CMOS cameras have rolling shutters. The Z1 and FX1 are probably the only cameras suitable for what you're doing since they are 3ccd.

Jack Kelly · June 21st, 2007, 05:11 AM

Hi,

Thanks loads for your reply.

Sorry, I suppose my question isn't so much "does the HC7 have a rolling shutter" so much as "is the HC7's rolling shutter significantly faster (and hence less of an issue) than the HV20's?"

I have read that the HC7 produces significantly less "rolling-shutter" artefacts than the HV20 (also, I believe that it is possible to produce a CMOS sensor which outputs full frames - e.g. the Red One's sensor).

Jack Zhang · June 21st, 2007, 05:23 AM

After my trial with filming a spinning CD at 1/725, there's just a slight and not extreme curve distortion in the moving part of the picture so it might be faster.

Jack Kelly · June 23rd, 2007, 03:38 AM

Great, thanks loads for running that test.

If you have an HC7, please may I ask you to perform another simple test so we can determine whether or not it has a rolling shutter:

Do several quick pans past any vertical lines (e.g. pan past a door or street lamp). Then play back the footage. Are the vertical lines still vertical?

Here's an example of what happens when you do fast pans on the HV20:

http://www.ssontech.com/content/crooked.mov

Many thanks,
Jack

[edited by mod; please do not post links to outside sites like this]

Jack Kelly · June 23rd, 2007, 05:17 AM

Hi again,

My apologies - I should have searched the forums more thoroughly before posting - there's another "rolling shutter" forum post on DVinfo here:

http://dvinfo.net/conf/showthread.php?t=95437

I propose that we stop this "HC7 rolling shutter & match-moving" thread and continue the discussion over on the "rolling shutter and lightning footage" thread.

Mikko Lopponen · June 24th, 2007, 12:35 PM

I'll bet that its the same speed in all of these hdv-cmos-cameras. 1/60th of a second it takes for the cmos to scan the picture.

The difference that HV20 "apparently" has is because it has a 24f mode that shows the distortions more. When you use 60i it will look the same as in hc7 etc.

HC1 seems to have the same amout of rolling shutter as hc3 and hv20. I haven't used the hc7 so it is plausible that there is improvement though I doubt it.

June 21st, 2007, 04:34 AM	#1
Jack Kelly Major Player Join Date: Oct 2004 Location: London, UK Posts: 243	HC7 rolling shutter & match-moving Hi there, Does the HC7 have a rolling shutter like the HV20? I ask because I'm keen to buy a cheap HDV camera that I can (occasionally) use for capturing footage for match-moving using SynthEyes. The HV20 has a rolling shutter which causes match-moving-killing distortions. Thanks, Jack __________________ Jack Kelly's filmmaking website AfterCarbon.org

June 21st, 2007, 05:11 AM	#3
Jack Kelly Major Player Join Date: Oct 2004 Location: London, UK Posts: 243	Hi, Thanks loads for your reply. Sorry, I suppose my question isn't so much "does the HC7 have a rolling shutter" so much as "is the HC7's rolling shutter significantly faster (and hence less of an issue) than the HV20's?" I have read that the HC7 produces significantly less "rolling-shutter" artefacts than the HV20 (also, I believe that it is possible to produce a CMOS sensor which outputs full frames - e.g. the Red One's sensor). __________________ Jack Kelly's filmmaking website AfterCarbon.org

June 23rd, 2007, 03:38 AM	#5
Jack Kelly Major Player Join Date: Oct 2004 Location: London, UK Posts: 243	Great, thanks loads for running that test. If you have an HC7, please may I ask you to perform another simple test so we can determine whether or not it has a rolling shutter: Do several quick pans past any vertical lines (e.g. pan past a door or street lamp). Then play back the footage. Are the vertical lines still vertical? Here's an example of what happens when you do fast pans on the HV20: http://www.ssontech.com/content/crooked.mov Many thanks, Jack [edited by mod; please do not post links to outside sites like this] __________________ Jack Kelly's filmmaking website AfterCarbon.org Last edited by Douglas Spotted Eagle; June 23rd, 2007 at 07:56 AM. Reason: links removed

June 23rd, 2007, 05:17 AM	#6
Jack Kelly Major Player Join Date: Oct 2004 Location: London, UK Posts: 243	Hi again, My apologies - I should have searched the forums more thoroughly before posting - there's another "rolling shutter" forum post on DVinfo here: http://dvinfo.net/conf/showthread.php?t=95437 I propose that we stop this "HC7 rolling shutter & match-moving" thread and continue the discussion over on the "rolling shutter and lightning footage" thread. __________________ Jack Kelly's filmmaking website AfterCarbon.org

June 21st, 2007, 04:57 AM	#2
Jack Zhang Inner Circle Join Date: May 2005 Location: Burnaby, BC, Canada Posts: 3,053	Unfortunately, all CMOS cameras have rolling shutters. The Z1 and FX1 are probably the only cameras suitable for what you're doing since they are 3ccd.

June 21st, 2007, 05:23 AM	#4
Jack Zhang Inner Circle Join Date: May 2005 Location: Burnaby, BC, Canada Posts: 3,053	After my trial with filming a spinning CD at 1/725, there's just a slight and not extreme curve distortion in the moving part of the picture so it might be faster.

June 24th, 2007, 12:35 PM	#7
Mikko Lopponen Major Player Join Date: Mar 2006 Location: Helsinki, Finland Posts: 393	I'll bet that its the same speed in all of these hdv-cmos-cameras. 1/60th of a second it takes for the cmos to scan the picture. The difference that HV20 "apparently" has is because it has a 24f mode that shows the distortions more. When you use 60i it will look the same as in hc7 etc. HC1 seems to have the same amout of rolling shutter as hc3 and hv20. I haven't used the hc7 so it is plausible that there is improvement though I doubt it.