Noise in Blacks

  • Thread starter Thread starter Guest
  • Start date Start date
G

Guest

Guest
First Off, I want to thank all of you guys for your input on the DVX. I finally picked mine up a week ago and love it!! So on to my question. I know this topic has been covered but need to ask again. When I completly close the iris, I notice there seems to be some noise in the picture. Is this a normal trait? Shouldn't I get complete black with the iris closed?

Any thoughts
Thanks

Steve
 
Re: Noise in Blacks

First question is this: are the gain settings switched off?
and second question:is your monitor of high quality?

I've never noticed grain in my blacks, ever...even with the iris wide open, that doesnt make a difference, black is black, its only when you artificially enhance the black levels you notice grain.

Unless I just can't notice it, and it's there in my footage too :P
 
Re: Noise in Blacks

O.k Mike hers's the scoop. I'm at 0db and using a sony 1345Q broadcast monitor. I did notice through more testing that lowering the M ped to around -3 helped but it comes back when raising the brightness on the monitor. I come from a film background so maybe this is somthing that I have to work out. Thanks for your input. :)

Steve
 
Re: Noise in Blacks

Here's somthing wierd too. When I plug my little sony dv camera up to my monitor using the same S cable, No noise. Black. On the DVX, switching between different gama's increases and degreases the noise effect. All settings are at 0. When I turn off the 24p mode all the noise seems to disapear. Is that just what I live with in 24p mode or is there somthing wrong with this camera? Just bought a week ago. Maybe some sort of burn in time for the chips? I'm stumped.

Thanks
Steve
 
Re: Noise in Blacks

How about uploading a GRAB for us to see? I have never experienced this problem myself. You say you're seeing this on a monitor; what about a tv, computer or on the LCD?
 
Re: Noise in Blacks

Hey John! Remember me? I was the dude pulling my hair out trying to make a desion on buying the DVX. You and a bunch of guys really helped me out. Thanks!! Now I will do my best to get a screen grab up. Justs a recap..With the iris fully stopped down, it looks like the gain is up slightly with some grain. Just to wierd. I did notice when I open up all the way in a dark room it's there too. It seems to go away when I introduce a bright object such as a table lamp. Acts like an Old film stock I used. The grain tightens when you put a bright object in frame. Anyway thanks for helpen on this.

Later:

Steve
 
Re: Noise in Blacks

Almost forgot. This is all going straight from the camera through a S cable to my broadcast monitor. didn't try capture or put it through a regular TV yet.

Thanks

Steve
 
Re: Noise in Blacks

HI Steve! I thought the name was familar. Well, jeez, register already!

Thinking out loud on this one; Did you do a proper WB or are you using a PRST?
 
Re: Noise in Blacks

The DVX100 (or probably any camera) wil have 6dB more noise in progessive than in interlaced. This is covered in one of the papers from Panasonic. In brief, during interlaced conversion the lines are averaged to reduce noise however this does result in a 29% reduction of vertical resolution.
In progressive scan no line averaging is possible. This gives a 29% increase in vertical resolution at the expense of a 6dB increase in noise.

Interesting side effect of this, shooting in 16x9 squeeze mode results in a 29% loss of vertical res but if you're shooting in progressive scan then the gain in vertical res offsets the loss.
 
Re: Noise in Blacks

Hey Joe, thanks for the info. It sounds like what your saying is normal for this camera. I'm going to have this noise when I'm wide open in a darken room. And thats that. This may also explain why the grain some what decreases when I introduce a bright object in frame. Interesting. So it also sounds like you don't think it's something I should contact Panasonic about.

Thanks!!

Steve
 
Re: Noise in Blacks

John.. I did do a proper WB and all that good stuff. And yes, I'm in the prosess of registering as we speak!!!! Love this camera!!! And Again, thanks to all of you out there for your input.

Steve
 
Re: Noise in Blacks

is your master ped at 0 too? if it is, try lowering it to the proper value so thatthe black level is correct.
 
Re: Noise in Blacks

Just a thought also, although I don't think it really has to do with a black grain issue, did you hold down the white balance button and balance your blacks as well. Usually this is used for masking dead pixels and such, but possibly it could help with your situation as well.
 
Re: Noise in Blacks

Hey guys. Yes, I have lowered the blacks and it does help out. Also did a black balance as well. Didn't seem to make a difference. Do you guys think I have dead pix already? The camera isn't even a week old

Thanks

Steve
 
Re: Noise in Blacks

maybe a defect unit...

I checked my AG-DVX100A and found no abnormal noise in blacks...
 
You must log in or register to reply here.
Back
Top