Image quality - artifacts/pixelation/I'm insane

JasonFox

JasonFox

Internet Sensation
Okay, I honestly have no idea what is going on here. I'm shooting 24PA, as usual, with no gain, etc. As you can see from these stills, there is what appears to be compression artifacts (for lack of a better term) in the video. The one with yours truly in it also has an M2 in the loop, so I did the second quick grab without it just to be sure. I did have to clean the heads recently, but the problem was there before the RCoD appeared. My scene settings are basically stock F6, so I'm not trying to crush the blacks or pump a color too much in camera. I'm using FCP4.5, but it shows up even when I'm outputing straight from the camera to TV via S-video (although it's harder to notice). Any ideas? Is a servicing needed? My images were much better when I first got the camera -- now that I really need it to shoot some stuff, this happens. Aye chihuahua! Any ideas?

Thanks,

Fox


 
The first image is just the interlacing artifacts of the "C" frame in the 24pA data sequence. If you edit your footage on a 24p timeline you'll never see that.
 
i agree with barry on the first. on the second besides the distortion from the anamorphic lens..you mgiht want to either change the shutter speed or open up the iris to let a little more light in. however i did a shot once when i first got the camera and got that rainbow grading/noise that you are seeing. it might be to uneven lighting or something, but i do see what you are talking about. try raising the light levels or some kind of balancing. that should help.
 
Thanks, guys. I realize I grabbed an interlaced frame on the first -- please ignore that. :) I am editing on a 24p timeline -- or maybe I just think I am, I'll check. Note the color blocking on the tile right behind me. Could I still possibly need more light even if I was already having to stop down the iris a bit? With the M2 on, I had the SLR lens at 2.8 and the DVX at 3.4 giving just a bit of zebra (@ 80%) in the blinds.

Thanks again,

Fox
 
i did a test shot once...green screen...and truly lit the area, but towards the corner of the wall the light started to fade off and that's where i noticed the grading of the light. which worsened with saturation. i truly don't know what causes it. it's something to experiment/test but it would be good to know why it happens. don't worry you are not alone.
 
Not so much the grain as, in the shot of me, that's a result of the of ground glass. It's pronounced color banding. Is it all really a matter of not having enough light? Unfortunately, I was unable to get outside in time to shoot some tests last night and will not have time tonight, either. But I'm having a hard time reconciling the idea that I don't have enough light when I'm having to stop down the lens (or lenses with the M2). But I guess I'll have to bust out the work lights and really flood the room to find out. Just hate using such hot lights when it's already 95 outside.

Fox
 
LOL yeah in summer lighting is great! :P

On another note I just cant see what your talking about. All I can make out thats an issue is grain and interlace lines.
 
yeah, the grain is obscuring the banding a bit in the top photo. I'll try to post another example tomorrow evening. Thanks.

Fox
 
jason i get the same thing and i'm not using a GG lens just the leica. you don't really need to flood the room with light...kinda just even it out. as i said i don't know what causes it because as i said above it was happening on a wall that i had lit, but as the light started to fall off the "banding" was there.
 
Well, I'm less worried about that wall (it's just where I had the camera set up after clearing out the kitchen so we could make dinner) than I am about the banding that seems to be going on in the first image. At least I know it's there. I need to upload a better example for you guys to check out. Stupid day job is cramping my style!

Fox
 
Yes, that's why I need to get another frame for you guys to check out. Schedule has not permitted it. Will do it tonight if I don't have to work late.
 
wait...just thought of something...are you using an LCD monitor?

reason i ask i was watching "rush hour" the other night and noticed the light/color grading during the movie. at the time i mentally wrote it off as "oh well it's mpeg", but then right now i was reading this post and put the two together...because right now i'm looking at your stuff on a CRT monitor and it's not there, but at home on my LCD it is...hey i could be wrong, just a thought.
 
I'll give that a shot, novelt. I am, indeed, using an LCD. I have a CRT hooked up with an ADSPyro, so I can watch it within FCP. Hey, where in TX are you?
 
far west texas...el paso. howdy! well here it's more hola! :grin:

actually in comparison on a CRT the grading is there, but more shadowy...whereas on the LCD it's colored noise.
 
You must log in or register to reply here.
Back
Top