Noise test shoot. No lighting and tweak in post

saru

saru

Active member
Hey guys.

I recently bought HVX200 and it is WONDERFUL.
Ergonomics are great and you feel it is a solid camera.
Though the two things I noticed;

* Low resolution LCD -> okay, I knew it and I'll get an external LCD anyway.

* NOISE -> there's noise, but I can live with it,,,,,,, though when you tweak the footage in post, you'll see awful amount of block noise !

I did a test shoot on this second matter and want to share the result - so that we can do something about it hopefully..


http://www22.tok2.com/home/hvx200/
There are lots of .png images so please be patient. QT .mov is available too.


Any idea how to handle this problem ? Light 2 stops over and bring the detail down ? Noise reduction filter ?
Any advice are welcomed.

cheers
 
Light 2 stops over and bring the detail down ? Yes!
You still have to watch the banding and blocking but it's not as bad.
 
holditnowfilms said:
Light 2 stops over and bring the detail down ? Yes!
You still have to watch the banding and blocking but it's not as bad.
Click to expand...

Is lighting 2 stops over the same as opening up the iris 2 stops?
 
Saru, do you have a DVX by any chance to test that exact same scene with? Apply the same filters to that footage so we can compare.

The kind of noise that is showing up on the HVX is, I believe much different from that of the DVX. I would love to put that arguement to rest (even if I'm seeing things incorrectly).
 
It looks like to me your pushing the dynamic range too far. Do you know how many stops difference you are from windo to black?
 
Hi Saru,

Can you try reducing the coring to -2 and the master ped to -4 to see if that helps reduce the noise (we'd love to see a comparison).

There is speculation that reducing the coring might help reduce the blocky nature of the noise. Generally, crushing the blacks is supposed to help reduce noice - although to my eyes BPRESS looks worse than HIGH - Bringing the master ped down to -4 takes the black levels closer to RGB black, I'd be interested to see if that helps.
 
holditnowfilms said:
Yes it is the same thing. You run into trouble when you are already wide open. Then you need more light.
Click to expand...

Understood. Thanks for answering.

I assume that while highlights/whites look blown out, they will be recoverable in post.
 
Once something is blown out you can't recover it because it means the information is gone. A blown out highlight means whatever detail was there is now replaced with white.
 
js33 said:
Once something is blown out you can't recover it because it means the information is gone. A blown out highlight means whatever detail was there is now replaced with white.
Click to expand...


It appears that the highlights are not actually blown out, they only appear that way on the lcd, due to it not being able to show the full range of what the camera is capable of.

The lcd looks blown out, but the camera is capturing more than the lcd shows, so if you blow the highlights out slightly, it will look normal on output..with this camera.
 
Be careful with that advice, as that depends entirely on how the brightness/contrast in your particular LCD is set up.

If you want to know whether you're really blowing out your highlights, set your zebras on 105% and USE THEM. Check for blowouts. If you're not seeing zebras, you're not blowing out, regardless of whether it "looks" blown-out on the LCD or not. If you are seeing zebras, you're in danger of blowing out.
 
I thought he was talking about really blownout highlights in which case they are not recoverable.
 
2nd Test

2nd Test

Hi all

Sorry I did not have time to respond but today I did another test. I also shot same scene with my old trusted DVX100.


http://www22.tok2.com/home/hvx200/



What I thought:

To me, HVX200 has much LESS visible noise than original DVX100. That's before and after applying the filter on my test. The DVX noise is more like video noise whereas HVX noise is more like grain (this also means noise is bigger tho). I even didn't realize DVX was THAT noisy.

However, HVX clearly has some problem with fine, low-lit gradient. Once you lit and shot low, you wouldn't want to raise the video signal in post - you'll see nasty blocky noise on there. That includes heavy or moderate colour tweaking too. You really can not take advantage DVCPRO HD's 4:2:2 colour once you low-lit. Sad.

The second test I did showed less block noise. I honestly don't know if it attributes to the settings (DETAIL CORING -2, MASTER PED -4). My gut feeling says that it is a result of slight change in lighting. There must be some point in terms of IRE where HVX begins to show blocks of noise.

For the gamma, B-PRESS and CINE V seems to be more susceptible to block noise than HIGH or CINE D. One interesting find - set MASTER PED +15 and close the iris and see the blue channel of the image (master monitor's blue only would do). The thing we see here could be the different gamma and noise block patterns.

So, as some other member have suggested, 2 stops over shoot could be best way to avoid all the noise issue with HVX.

What do you guys think ?
 
Saru,
did you have same amount of light when you shot with dvx as with hvx?
If you did, dvx seems to be at least one stop faster.
Does anybody know dvx100 A/B/E 's chips' pixel sizes?
 
toke lahti said:
dvx seems to be at least one stop faster.
Does anybody know dvx100 A/B/E 's chips' pixel sizes?
Click to expand...
It actually looks 2 stops faster to me - look at when you can see the detail on the front of the G5 grille clearly in both cameras.

The noise in the DVX is much finer and "grain-like," and even though it's there, I find it far more pleasing than the blocky mess the HVX puts out.
 
Instead of watching the lame Oscars last night. I did a bunch of tests. My conclusion is this:

- Matrix set to Normal will yield less chroma noise. Cine-matrix has the same noise but contains more color. I prefer having more of the lumance type of noise.

- Detail coring and detail level - don't really descrease the noise. It will try to blur it which makes it much blockier. This will be evident where there is subtle gradations. increasing coring and lessening detail will make the graded areas band.

- Cine D will be the best to reduce banding problems.


So..... I found the best setting for me is to use Cine-D, Detail level 0, Detail Coring 0, and Matrix set to Normal.

I know it sounds strange but that's what it came to. By setting coring to a higher value and the Detail low, made the noise artifacting look very videoish because it gave the appearance of removing noise in certain parts of the scene. Leaving those at the default settings at least made the noise evenly spread everywhere without looking blocky. I encourage people to do there own tests.
 
The banding issues after colour correction are, I think, due to the aggressive DVCProHD compression removing dithering noise that would get rid of the worst effects of 8bit banding. The weights used in video codecs tend to compress shadows more than mid ranges / highlights, and in shadows, you have less quantisation levels anyway. This leads to banding when you increase brightness, (or remove masking colour). Best thing to do is to make sure nothing in the scene gets too dark, and reduce brightness in post if need be to get the mood looking right.

I'm going to try out my new noise reduction algorithm on the footage you provided on your website, when I can get it to download right!

Graeme
 
I have been interested in these noise discussions - but the issue all but dissappears outside of a testing env. I just completed a music vid this weekend - and it had a lot of dark tones. Noone noticed any noise and to be honest I didnt notice any cause I stopped looking once it became about the image I was capturing.

If you want to see some samples go here.

http://www.dvxuser.com/V6/showthread.php?t=48626
 
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