Question about video grain at DVinfo.net

Steve Montoto · June 11th, 2007, 08:05 AM

I got my A1 about a month and a half ago and I have noticed that I seem to have video grain no matter what I shoot or how I shoot. I have been using mainly (60i Tv 60 shutter) but have also shot 30f and 24f with the same results. (there is grain in the shadows whether in daylight or inside shots, alot more on the inside shots, it almost looks like color noise, makes the video look not very sharp) Comming from a VX2000 I dont recall having this issue.

Is this normal? Its not terrible but since this is my first HD cam I was curious if im just expecting too much or possibly doing something wrong. I monitor the video on a samsung 23" lcd and it is also visible connecting directly to a 46" HD TV.

Any suggestions would be greatly appreciated.

Steve

edit: I am not using AGC and this is noticed at -3,0,6db gain

Eric Weiss · June 11th, 2007, 09:15 AM

try shooting something in full manual mode with no preset
at an appropriate exposure. if there is still grain, shoot something in decent light on green box mode. if there is still grain, you have an issue.

my shots are typically noise free and the A1 is wonderful in low light.

i have noticed that a few of the presets can cause grainy shots.

Trish Kerr · June 11th, 2007, 10:38 AM

can you post some video samples so we can see what you are seeing?

Trish

Don Palomaki · June 11th, 2007, 02:30 PM

What are the camcorder settings and light levels where you are shooting?

Video "grain" is caused by slightly different light sensitivities and "dark currents" of individual pixels in the CCDs. It is mainly apparent in image shadow areas and when shooting with high gain and/or with slow shutter speeds. It may be more apparent if the camcorder is hot (used in high temperatures). It also is more apparent in flat images (e.g., plain gray walls and unchanging content) and less apparent in images with complex content and with motion. Unlike film gain, which varies from frame to frame, it tends to be fixed per the pixel pattern and thus can be more noticeable in the moving image. It can be significantly mitigated using the noise reduction and black level settings and shooting with adequate light levels.

I suspect that the VX series has this sort of image processing built into its default settings, while the A1 expects the shooter to make these adjustments to suit the shooting situation.

Steve Montoto · June 11th, 2007, 04:10 PM

Here are a few full rez screenshots.

The Manual mode shots are 60i,1/60,-3db gain, NO Custom Preset(off)

Lighting for all shots outside was daylight 11:30am, Inside was available daylight comming though windows(no lights on)

Greenbox mode shots were 60i

rightclick and use save as to save the file.

http://onsiteaudio.com/ManualModeOutside.tif

http://onsiteaudio.com/ManualModeInside.tif

http://onsiteaudio.com/ManualModeInside2.tif

http://onsiteaudio.com/GreenBoxOutside1f.tif

http://onsiteaudio.com/GreenBoxInside1.tif

http://onsiteaudio.com/GreenBoxInside2.tif

http://onsiteaudio.com/TVMode60i.tif

Thank you for everyones responses.

Steve

Paul Cronin · June 11th, 2007, 05:26 PM

Don have you used the NR1 and NR2 settings with success in 30F?

Steve Montoto · June 11th, 2007, 10:03 PM

Quote:

Originally Posted by Steve Montoto

Here are a few full rez screenshots.

The Manual mode shots are 60i,1/60,-3db gain, NO Custom Preset(off)

Lighting for all shots outside was daylight 11:30am, Inside was available daylight comming though windows(no lights on)

Greenbox mode shots were 60i

rightclick and use save as to save the file.

http://onsiteaudio.com/ManualModeOutside.tif

http://onsiteaudio.com/ManualModeInside.tif

http://onsiteaudio.com/ManualModeInside2.tif

http://onsiteaudio.com/GreenBoxOutside1f.tif

http://onsiteaudio.com/GreenBoxInside1.tif

http://onsiteaudio.com/GreenBoxInside2.tif

http://onsiteaudio.com/TVMode60i.tif

Thank you for everyones responses.

Steve

Any suggestions?

Don Palomaki · June 12th, 2007, 06:59 AM

Paul.
I've mainly shot 60i SD, not 30F. I've used NR1 with satisfactory results mainly with indoor, poor light situations, with 12 and 18 dB gain, and 1/30 shutter on occasions. By satisfactory results, I mean they met my expectations and served my purpose. There is no substitute for good light.

Steve: Opening the .TIF files in Photoshop (but not on a high end graphics work station with a corresponding quality monitor) I am not sure what the issue is. The images have no obvious fault in terms of grain that shows up on the PC I'm using. They just have the somewhat flat "out of the box" look of the A1, not the higher default color saturation and contrast levels found with many camcorders.

Trish Kerr · June 12th, 2007, 07:33 AM

You can see some of the interlacing artifacts on a few of the stills. The stills themselves don't look bad. But it's hard to judge grain (noise) on stills.

If you are still unsure, post a clip that you feel really showcases the grain problem you are concerned about. Then we can really tell if there is a problem with the camera.

In my experience the only time I notice the noise getting bad is settings over 6db gain. And usually only in big dark areas. In normal conditions there will be some pixelation but it shouldn't be terrible looking. You also can't look at the image from a foot away on a 40 inch LCD - even cable HD feeds or dvds will show the noise that close. But from a few feet back, the picture should be looking very good.

Trish

Steve Montoto · June 12th, 2007, 07:37 AM

Quote:

Originally Posted by Don Palomaki

Steve: Opening the .TIF files in Photoshop (but not on a high end graphics work station with a corresponding quality monitor) I am not sure what the issue is. The images have no obvious fault in terms of grain that shows up on the PC I'm using. They just have the somewhat flat "out of the box" look of the A1, not the higher default color saturation and contrast levels found with many camcorders.

Don,

http://onsiteaudio.com/ManualModeOutside.tif

The grainy shadows under the bench in this pic are the ones I was curious about, I notice this in most of my indoor shots also. (the noise is like tiny color flicker)

I could be completely dumb if this is normal. I guess I have been so used to the videoish look of my vx2000 I need to evolve into this camera.

Edit: Thank you Trish I posted at the same time you did and didnt see your response. I could be completely off base with this issue.

Trish Kerr · June 12th, 2007, 07:55 AM

Whatever you do, don't feel bad about posting the question. You want piece of mind on the camera. There have been a few cases where there was a problem with the camera itself and posting for others opinions helped determine that.

Trish

Paul Cronin · June 12th, 2007, 08:09 AM

I agree Steve I had a grain problem with my camera and it was the camera. So ask away until you feel comfortable.

I do not see the problem with your camera. Try the custom presets and use manual mode. You will be surprised how many modes the A1 has. That way you can find/make the preset that will match the image you seek.

Cary Lee · June 12th, 2007, 11:31 AM

On another site...some posters said to change you L gain setting to -3 vs +3 that was set to default and to keep there. Gain=Grain.

Piotr Wozniacki · June 12th, 2007, 11:35 AM

Quote:

Originally Posted by Cary Lee

On another site...some posters said to change you L gain setting to -3 vs +3 that was set to default and to keep there. Gain=Grain.

Steve already said earlier that gain was at -3dB. With my V1, I'm getting a noise similar to what can be seen in the shadow under the bench with gain higher than 6dB.

June 11th, 2007, 08:05 AM	#1
Steve Montoto Major Player Join Date: Jun 2003 Location: USA Posts: 302	Question about video grain I got my A1 about a month and a half ago and I have noticed that I seem to have video grain no matter what I shoot or how I shoot. I have been using mainly (60i Tv 60 shutter) but have also shot 30f and 24f with the same results. (there is grain in the shadows whether in daylight or inside shots, alot more on the inside shots, it almost looks like color noise, makes the video look not very sharp) Comming from a VX2000 I dont recall having this issue. Is this normal? Its not terrible but since this is my first HD cam I was curious if im just expecting too much or possibly doing something wrong. I monitor the video on a samsung 23" lcd and it is also visible connecting directly to a 46" HD TV. Any suggestions would be greatly appreciated. Steve edit: I am not using AGC and this is noticed at -3,0,6db gain

June 11th, 2007, 02:30 PM	#4
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,488	What are the camcorder settings and light levels where you are shooting? Video "grain" is caused by slightly different light sensitivities and "dark currents" of individual pixels in the CCDs. It is mainly apparent in image shadow areas and when shooting with high gain and/or with slow shutter speeds. It may be more apparent if the camcorder is hot (used in high temperatures). It also is more apparent in flat images (e.g., plain gray walls and unchanging content) and less apparent in images with complex content and with motion. Unlike film gain, which varies from frame to frame, it tends to be fixed per the pixel pattern and thus can be more noticeable in the moving image. It can be significantly mitigated using the noise reduction and black level settings and shooting with adequate light levels. I suspect that the VX series has this sort of image processing built into its default settings, while the A1 expects the shooter to make these adjustments to suit the shooting situation. __________________ dpalomaki@dspalomaki.com

June 11th, 2007, 05:26 PM	#6
Paul Cronin Inner Circle Join Date: Dec 2005 Location: Rhode Island Posts: 4,048	Don have you used the NR1 and NR2 settings with success in 30F? __________________ Paul Cronin www.paulcroninstudios.com

June 12th, 2007, 06:59 AM	#8
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,488	Paul. I've mainly shot 60i SD, not 30F. I've used NR1 with satisfactory results mainly with indoor, poor light situations, with 12 and 18 dB gain, and 1/30 shutter on occasions. By satisfactory results, I mean they met my expectations and served my purpose. There is no substitute for good light. Steve: Opening the .TIF files in Photoshop (but not on a high end graphics work station with a corresponding quality monitor) I am not sure what the issue is. The images have no obvious fault in terms of grain that shows up on the PC I'm using. They just have the somewhat flat "out of the box" look of the A1, not the higher default color saturation and contrast levels found with many camcorders. __________________ dpalomaki@dspalomaki.com

June 12th, 2007, 08:09 AM	#12
Paul Cronin Inner Circle Join Date: Dec 2005 Location: Rhode Island Posts: 4,048	I agree Steve I had a grain problem with my camera and it was the camera. So ask away until you feel comfortable. I do not see the problem with your camera. Try the custom presets and use manual mode. You will be surprised how many modes the A1 has. That way you can find/make the preset that will match the image you seek. __________________ Paul Cronin www.paulcroninstudios.com

June 11th, 2007, 09:15 AM	#2
Eric Weiss Major Player Join Date: Mar 2007 Location: Philly,PA Posts: 360	try shooting something in full manual mode with no preset at an appropriate exposure. if there is still grain, shoot something in decent light on green box mode. if there is still grain, you have an issue. my shots are typically noise free and the A1 is wonderful in low light. i have noticed that a few of the presets can cause grainy shots.

June 11th, 2007, 10:38 AM	#3
Trish Kerr Major Player Join Date: Mar 2007 Location: Canada Posts: 294	can you post some video samples so we can see what you are seeing? Trish

June 11th, 2007, 04:10 PM	#5
Steve Montoto Major Player Join Date: Jun 2003 Location: USA Posts: 302	Here are a few full rez screenshots. The Manual mode shots are 60i,1/60,-3db gain, NO Custom Preset(off) Lighting for all shots outside was daylight 11:30am, Inside was available daylight comming though windows(no lights on) Greenbox mode shots were 60i rightclick and use save as to save the file. http://onsiteaudio.com/ManualModeOutside.tif http://onsiteaudio.com/ManualModeInside.tif http://onsiteaudio.com/ManualModeInside2.tif http://onsiteaudio.com/GreenBoxOutside1f.tif http://onsiteaudio.com/GreenBoxInside1.tif http://onsiteaudio.com/GreenBoxInside2.tif http://onsiteaudio.com/TVMode60i.tif Thank you for everyones responses. Steve

June 12th, 2007, 07:33 AM	#9
Trish Kerr Major Player Join Date: Mar 2007 Location: Canada Posts: 294	You can see some of the interlacing artifacts on a few of the stills. The stills themselves don't look bad. But it's hard to judge grain (noise) on stills. If you are still unsure, post a clip that you feel really showcases the grain problem you are concerned about. Then we can really tell if there is a problem with the camera. In my experience the only time I notice the noise getting bad is settings over 6db gain. And usually only in big dark areas. In normal conditions there will be some pixelation but it shouldn't be terrible looking. You also can't look at the image from a foot away on a 40 inch LCD - even cable HD feeds or dvds will show the noise that close. But from a few feet back, the picture should be looking very good. Trish

June 12th, 2007, 07:55 AM	#11
Trish Kerr Major Player Join Date: Mar 2007 Location: Canada Posts: 294	Whatever you do, don't feel bad about posting the question. You want piece of mind on the camera. There have been a few cases where there was a problem with the camera itself and posting for others opinions helped determine that. Trish

June 12th, 2007, 11:31 AM	#13
Cary Lee Regular Crew Join Date: Mar 2004 Location: Hollywood USA Posts: 128	Change gain default setting On another site...some posters said to change you L gain setting to -3 vs +3 that was set to default and to keep there. Gain=Grain. __________________ Canon XHA1, SGpro,Flip,FF, RR Mattebox, Nebtek V-R70p-HDA with Canon, Nikkor Primes 24mm f2.8, 28mm f2.8, 35mm f2.0, 50mm f1.4, 85mm f1.4, 105mm f1.8, 135mm f2.0, and 300mm f4.0.