Lens Cap

P

Policar

Carbonite Member
Either this will be a somewhat interesting post or a very moronic one. Probably moronic, but I'm making it anyway. Anyhow, some have speculated that the dvx uses a small amount of built in, non-adjustable gain, to get the impressive rating of F11 at 2000lux and this results in noise in blacks, even with no gain turned on and even in good light. I know I have noticed noise in dark areas even when shooting outdoors near noon. Btw, you have to look pretty closely--the noise is hardly apparent in a still image (I will post a magnified .mov later if there's any interest.)

Here's a screen grab of footage shot with the lens cover on, progressive scan, with no gain on. If you look closely, there's significant fine noise. It's hard to see in a still grab, but in motion it's definitely there. I think I may record a clip of this and apply it (with the add transfer mode) over some CGI I'm incorperating into my upcoming short movie.

noise.jpg


I also have an image of +18db noise. It's honestly a bit frightening.
 
Re: Lens Cap

Well, my computer monitor is calibrated, so blacks are really black, right now I don't see grain in the black picture. But if I dial the brightness up, I see some grain, but hee, that is excactly what I get in al lot of my footage. Two days ago I was shooting a very blue sky, guess what, grain all over the place!

I think I see it a lot on mini dv footage, I work as a freelance editor for some tv stations, and we were capturing mini dv footage some day, and the girl who has shot it said to me that there is a lot of grain in the footage, it strikes me also.
So maybe that is just the weakness of mini dv, or not the right setting?
BTW, is it grain or is it just the dv compression!?

But try to put down the detail level, I shoot in F5 mode with detail level on -7, it looks more like film that way, and you get a nice solid picture. Maybe you think it is to soft, but for movie it is fine. I view it on a projection screen.
 
Re: Lens Cap

What's your master pedestal set at? That can make a difference...
BTW: You're right about the +18db. The gain on these DVX's is not what I characterize as good. I love my DVX100A but use it with no more than +3db of gain...These are not low light machines like some of the Sony's. However, the trade offs are worth it. That's why I bought both. If I have to get good shots in really low light no matter what, I go with my Sony. For pretty much everything else, I use my Panasonic's...

Andrew
Crystal Clear Media
 
Re: Lens Cap

It looked noisier on my laptop. I swear!

If you saw it in motion it'd be even better. I may have to upload a .mov of invisible noise just for kicks. Seriously, though, it looked really noisy on my miscalibrated laptop.
 
Re: Lens Cap

It was a one week shoot, but we went back after we'd done some editing for another two days of re-shoots. It's been in post for about a month now, and we're almost happy with the results. A little bit more color correction on the cgi and some more audio mixing and it should be all set.

I've decided that I'm going to post a thread with noise at each gain level and in 24p versus 60i, because that--apparently unlike this--might be useful. Anyone agree or disagree?
 
Re: Lens Cap

I'd like to see post of noise in each gain level and frame rate, as well as noise levels at different cine modes.

sure, why not.
 
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Whats the point of measuring the noise level of the circuitry when 0% light is getting to the CCD? Please do stop this home-brewed scientific experiment... especially counting how pointless this is.
 
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I suppose you're right, although--to be honest--one thing that has always bothered me about the dvx is the high noise level in blacks...and the gain on the camera is pretty ugly as well. I wish there were an objective way to measure the noise level of one camera compared to another, especially as I have not seen this kind of noise in the dvx's competition, but I guess it is more complicated than just taking a screen capture of a 0 lux environment.

Well, thanks for the honest response. I suppose I won't waste my time.
 
Re: Lens Cap

AndrewD,

What is a master pedestal, if you don't mind me asking?

I am sorry, I am still a newbie to most of the terms you guys use here. Sometimes I just feel too ignorant when I read some of the posts. But, when we want to learn, we ask right?

All the best

Fidel.
 
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