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-   -   Blurred motion (https://www.dvinfo.net/forum/jvc-gy-hd-series-camera-systems/64411-blurred-motion.html)

Henrik Helms April 5th, 2006 09:48 AM

Blurred motion
 
Hi!
I have just finished a documentary and found a strange behaivoir in some of the pictures.
I have shot the documentary in SD 16:9 PAL with the wideangle lens - and e.g. in the interviewposition I find something that looks like a kind of motion blur when the interviewperson moves her head quickly - the hair and the skin-colour seems to blur and having problems in updating the colours.
Has anyone experienced that?? And knows why this is happening. Is it a setup problem or....

Hans Pool April 5th, 2006 11:20 AM

blur
 
I have the same problem! Some time ago I asked this forum about the blurring images, and somebody called them ghostframes. I really don't now what it is. Sometimes I think it's the bad quality of the lens. But when I film with aperture 8 or even 11 I've still this problem!

Maybe it's gone using the expensive wideangle lens. Next week I'm gonna try it.

Can you show us some footage or frames?

Joel Aaron April 5th, 2006 12:21 PM

Quote:

Originally Posted by Henrik Helms
Hi!
I have just finished a documentary and found a strange behaivoir in some of the pictures.
I have shot the documentary in SD 16:9 PAL with the wideangle lens - and e.g. in the interviewposition I find something that looks like a kind of motion blur when the interviewperson moves her head quickly - the hair and the skin-colour seems to blur and having problems in updating the colours.
Has anyone experienced that?? And knows why this is happening. Is it a setup problem or....

Since there a many examples of the HD-100 handling even very fast motion well I'd say it's a setup issue.

You specifically mention skin tones - are you using the skin tone detail feature? Maybe it doesn't handle motion well. Are you using the motion smoothing feature? I haven't heard many good things about it.

I've never seen this problem myself.

Steven Thomas April 5th, 2006 12:28 PM

Were you shooting 24P at 48 shutter, or 24 shutter?
A 24 shutter will give you blurred motion. This is the nature
of exposure time vs movement with ANY camera


Hans,
I'm not sure where an f-stop of F8 has to do with motion blur.

I can suggest to never use any stop less the F8. Diffraction will
be an issue stopped down less that F8.

All lens on ANY camera have a sweet spot. Some are better than others.
This is the nature of lens.

Henrik Helms April 5th, 2006 12:37 PM

Quote:

Originally Posted by Steven Thomas
Were you shooting 24P at 48 shutter, or 24 shutter?
A 24 shutter will give you blurred motion. This is the nature
of exposure time vs movement with ANY camera

As mentioned I shot it in SD PAL - and it was en 25P mode and the shutter was off.

Henrik Helms April 5th, 2006 12:38 PM

I used the wideangle lens
 
Quote:

Originally Posted by Hans Pool
Maybe it's gone using the expensive wideangle lens. Next week I'm gonna try it.

I shot my material with the wideangle lense...so.....

Henrik Helms April 5th, 2006 12:47 PM

No...
 
Quote:

Originally Posted by Joel Aaron
You specifically mention skin tones - are you using the skin tone detail feature? Maybe it doesn't handle motion well. Are you using the motion smoothing feature? I haven't heard many good things about it.


The skin detect is off and the motion smothing is not an option in SD mode

Fabrizio Sciarra April 5th, 2006 12:52 PM

I had the same trouble a while ago shooting with my z1.
After many testing,(i was trying to over and under crank) i finally find out that the ghost frames are strictly related to the shutter speed. Do not confuse the shutter speed with the frame rate. 25p it means you're shooting at 25 frames per second and have nothing to see with the speed of the shutter. Hope it helps

Henrik Helms April 5th, 2006 01:48 PM

Quote:

Originally Posted by Fabrizio Sciarra
I had the same trouble a while ago shooting with my z1.
After many testing,(i was trying to over and under crank) i finally find out that the ghost frames are strictly related to the shutter speed. Do not confuse the shutter speed with the frame rate. 25p it means you're shooting at 25 frames per second and have nothing to see with the speed of the shutter. Hope it helps

But when the shutter is set to off - then it should not be affecting anything...

Nate Weaver April 5th, 2006 01:57 PM

Shooting DV mode 25P with shutter off means the effective shutter speed is 1/25th.

Turn the shutter on and set to 1/50th.

Steven Thomas April 5th, 2006 02:26 PM

Quote:

Originally Posted by Nate Weaver
Shooting DV mode 25P with shutter off means the effective shutter speed is 1/25th.

Turn the shutter on and set to 1/50th.

Yes,
No wonder. I guess I missed the shutter off in his post.
As Nate mentioned, with the shutter off the exposure time is based
off of your frame rate. This explains why you're getting motion blur.
This is normal

Henrik Helms April 5th, 2006 02:36 PM

Quote:

Originally Posted by Nate Weaver
Shooting DV mode 25P with shutter off means the effective shutter speed is 1/25th.

Turn the shutter on and set to 1/50th.

Thanks for the advice Nate! I do that at once!

Tim Dashwood April 5th, 2006 04:37 PM

Quote:

Originally Posted by Nate Weaver
Shooting DV mode 25P with shutter off means the effective shutter speed is 1/25th.

Turn the shutter on and set to 1/50th.

Yes this is a silly default for DV mode on the HD100 and XL2.

In DV25P mode on the "E" model, the default shutter OFF is 1/25th. It of course should be 1/50th. The same goes for DV24P and 1/24th on the "U" model. It should be 1/48th.

At least they got it right in the HD modes!

Henrik Helms April 6th, 2006 12:38 AM

Quote:

Originally Posted by Tim Dashwood
Yes this is a silly default for DV mode on the HD100 and XL2.

In DV25P mode on the "E" model, the default shutter OFF is 1/25th. It of course should be 1/50th. The same goes for DV24P and 1/24th on the "U" model. It should be 1/48th.

At least they got it right in the HD modes!

Hi Tim!
Just to get this right. You are saying that in HD mode - if you have the shutter turned off - it will work OK in this mode?? Is the default in HD 1/50th when turned off...

Brian Drysdale April 6th, 2006 06:34 AM

Quote:

Originally Posted by Henrik Helms
Hi Tim!
Just to get this right. You are saying that in HD mode - if you have the shutter turned off - it will work OK in this mode?? Is the default in HD 1/50th when turned off...

You should normally keep the shutter ON when shooting progressive.

You can switch the shutter OFF if you need the extra exposure, however, you will get increased blurring on any motion.

Because the JVC is progressive when shooting HDV the default will be a shutter speed of 1/50th when shooting 25p.


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