C100: Vertical lines in underexpose area

Doug_EX

Doug_EX

Well-known member
Underexposed-vertical lines.jpgCan someome can tell me if this is normal on this camcorder? Vertical lines in the dark (underexposed) area.
 
I'm wondering if there's a way you can provide a 1:1 pixel version of this - I can see all kinds of things that gives me a shiver, but I could put them down to the fairly aggressive way images get posted to the board - they're imported, scaled and recompressed and therefore somewhat untrustworthy for analysis. It may have masked what you're seeing and created stuff the rest of us see (the stuff in the light is pretty unpleasant! LOL) - there's nothing better than a PNG, and 100% JPEGs too.

Another thing, whilst we're pixel peeping, does 'what you see' appear in some frames but not others? I have a 'torture test' clip of leaves in the wind, and over a number of frames, the quality varies according to a pattern. Let's say 5 is good, 0 is crap. So from a good frame:

5, 1, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 3, 1, 1, 5 (maybe 4 and it goes on)

Furthermore, the '1' frames show horizontal issues (not vertical) which seem to stem from an inherent 'interlace' approach to encoding. But I digress...

Vertical bits?
 
What ISO are you shooting at? I found anything over 4000 introduced vertical banding if you looked close enough. a 1:1 as Matt said would be very helpful to pinpoint the issue.
 
Black balance. Lower your master ped. While the camera is great in low light, it's not a night vision device. Maybe use a different profile other than WDR in that kind of situation. Black balance (did I say that already). Increase your NR in super low light to +2 or 3.

And yes, it is normal. Your camera is fine.
 
Yes, the iso was at least 6400 I think. I just wanted to push the camera to the extreme to see when the image would fall apart. I was panning in my living room to test my new Tokina 11-16 and when I ended up near the book shelf, I saw some vertical lines and was wondering if it was normal. Thank you!
 
Totally normal. You need to make a profile for low light high ISO shooting.

I often use Brian C Weed's REC709 with NR increased to +2 for high iso lowlight shooting. I used these settings in the following that was shot at 5000iso using the 24-105 at F5.6-F8. THe only lighting is from the dimmed down model lamps and a bit of creep from the closed overhead skylight. Vimeo will show some compression, but trust me when I say the master file is clean clean clean and sharp sharp sharp.
password: sebree
 
I had a problem with C300 where in one area I was getting in some frames horizontal lines from left side extending about 60 - 80% to the right. The problem was very visible at high ISO (6400+) in underexposed footage. The camera was sent to warranty repairs - according to Canon its "sensor assembly" was replaced.
 
For me it's not just in one area...it's in the dark area. I noticed it again today at 850 iso and I was outside. I must admit I did not black balance.
 
Matthew B said:
What PP are you using?
Click to expand...
You mean CP (custom picture)? Wide DR.
I did some tests this morning...I think my problem was really that I didn't black balance often enough. I remember changing iso setting quite a few times but almost never BB.
 
https://vimeo.com/79568437
I did a few test since my first post. Black balance did not change a thing. The vertical lines are really visible with the lens cap on. The vertical lines are always there and there pattern doesn't change. Example: There is a vertical line that is wider than others at about 2/3 (from left) on the image. This line will never move. It will be more visible in underexposed area for sure but its there. The vertical lines seems more visible on the cam's lcd than on my computer.
I upload a test on vimeo. There some compression from vimeo that doesn't allow to see very well the lines.

password: vert
 
Wow...just found something quite interesting. The ''peripheral illumination correction'' was set to ''on''. I set it to ''off'' and the vertical lines disappeared. Does anyone has an explanation for this?
 
Rodney Charters, ASC talks about this on the below video. In the video he talks about the vertical lines as "Fixed Pattern Noise". He says that he ran into it on the Red camera at above 2000 ISO. It sounds like you are running into it on the C100. He said that he did not run into it on the C300, but as noted above, that might not be the case. If this is what you are dealing with on the C100 there just might not be anything you can do about it as it is a flaw in the sensor design.

Here is the video, he talks about the "Fixed Pattern Noise" starting at about 3:05.


The Wikipedia page on Fixed Pattern Noise.
 
Alexsey1976 said:
Yes there are these lines on my C100.
These lines appear when switching ISO me too wondering is this normal?

Total darkness ISO 500<--->10000:
https://dl.dropboxusercontent.com/u/88377485/00053.MTS

Dark scene ISO 500<--->12800:
https://dl.dropboxusercontent.com/u/88377485/00055.MTS
Click to expand...

It seems to be the same problem that I noticed on my C100. Like I said in my last message, I set to ''off'' the ''peripheral illumination correction'' and the vertical lines disappeared. Hope this help.
 
And like I said previously, the lines are always there no matter what the ISO settings and they are fixed...they don't move on the screen. But they will almost never be visible in non-dark areas.
 
It looks like this is a feature of the C100. I also have a Sony FS100, there has never been such lines.
I solved the problem this way:
Black - Master Pedestal: -2
Black - Master Black - Red: -2
Black - Master Black - Green: -3
Black - Master Black - Blue: -5
 
Last edited:
You must log in or register to reply here.
Back
Top