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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Black Shading Noise Real-time Indication

Hey Tim,

Thank you for your reply.

Sure if I crush the blacks enough then the noise will go away . . . taking with it most of the shadow detail . . . but that's what shooting AVCHD with an AF100 is for ; -)

Moving the ISO or Exposure sliders in CineX does not change the Gray Bar indicator.

Compression setting: since my original tests were driven at trying to see if changing Frame Rate / Resolution affected the Black Shade Calibration, I went with a higher baseline compression setting since, at 5K / 96pfs, the best setting possible is RC12:1. My thinking was that to take the RC setting out of the equation set it at what the higher frame rates would require then leave it within a small range for the tests.

I'm not ready to restrict myself to 7:1 or below since that rules out the basic reason I purchased the Epic - High Frame Rate / 5K Quality. Even at 75fps the minimum 5K compression is RC10:1 - if that produces unworkable noise in the blacks then we got a purchase decision problem.

Would love to put the speculation to rest and hear from the Engineers at RED who know the answers to all my above questions.

Thank you all REDusers for the input,

-Josh
 
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Push the little R3D button under the viewing window to generate a single R3D frame, which can then be uploaded or attached easily enough (it's only around 1.5MB per RAW 5K frame).

Looking at your Photoshop levels I'd say it's more likely that RedCine-X is giving an erroneous indication that blacks (or something) is clipping at the bottom end. Could also be HDRx X frame if you shot with that enabled?

Anyway, if you can upload an R3D frame others can look for you. For example, it might be only in the Mac based RedCine-X and not the Windows version. Having an R3D can help determine across multiple systems if there's an error in the software or shooting parameters or any number of other scenarios.

HTH

Cheers from Tokyo,

Paul :)
 
Don't seem to be able to attach the R3D files through the Advanced window in REDuser ("invalid file") so here is the links to them through DropBox (give it a minute to upload - I'm basically on dial-up here in NZ):

http://dl.dropbox.com/u/51544095/A010_C008_11285Y.0000000F.R3D
http://dl.dropbox.com/u/51544095/A010_C024_1129TR.0000042F.R3D

Oh and . . . Paul, thank you for the help! Please let me (and the other couple thousand who have viewed this thread but have not chimed in) know what issues you are looking for and how you analyze the R3D snapshot.
 
Here's a couple screen shots of the files uploaded to DropBox. Notice the RC compression rates of 9:1 and 6:1 to address the test variable of compression. Notice also the pegged Gray Bar. Fuckstick!

RC9:1
6430038545_f8a30c9edb.jpg


RC6:1
6430038303_2a4cba9d8d.jpg
 
Josh Beadle said:
Moving the ISO or Exposure sliders in CineX does not change the Gray Bar indicator.
Click to expand...

Both ISO and exposure is implemented thru a gamma function, which doesn't affect the black point. Try the shadows slider, it will affect the "almost black" pixels, so you can lift the levels off the black cut off.

It does seem that there is some funky stuff going on with the scopes, when the processing is set to a lower res. For example the grey bar will show at 1/4 res but not on 1/1 res without changing the image parameters.
I can see from your grabs you are at 1/8 res, try set it to 1/1 instead.
 
Quick grab from the same image at two different res settings:
redx1.png

redx2.png

Just seems to be the lack of precision in the image reconstruction at the lower res settings.
 
I managed to get rid of the grey bar in one of the shots with a combination of some shadow adjustments, contrast, a curve, adjusting the lift, gamma gain, but what really did it and got it to pop away instantly was using the alchemy group and adjusting the clarity slider. This doesn't really answer your question as it's not conclusive at all as to whether this is caused by a sensor default, redcineX, or something else from my end... sorry.

hope you figure it out!
 

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Josh Beadle said:
Don't seem to be able to attach the R3D files through the Advanced window in REDuser ("invalid file") so here is the links to them through DropBox (give it a minute to upload - I'm basically on dial-up here in NZ):

http://dl.dropbox.com/u/51544095/A010_C008_11285Y.0000000F.R3D
http://dl.dropbox.com/u/51544095/A010_C024_1129TR.0000042F.R3D

Oh and . . . Paul, thank you for the help! Please let me (and the other couple thousand who have viewed this thread but have not chimed in) know what issues you are looking for and how you analyze the R3D snapshot.
Click to expand...

01.jpg

02.jpg


I do not see any grey bar ?!?
RedCine-X Pro build 7.17777 buid Beta
 
Anders Holck said:
Just seems to be the lack of precision in the image reconstruction at the lower res settings.
Click to expand...
I could verify Anders' findings on both beta 5 and beta 7 of RCX Pro. Going from 1/8 rez to Full got rid of the grey bar entirely.
 
Petri Teittinen said:
I could verify Anders' findings on both beta 5 and beta 7 of RCX Pro. Going from 1/8 rez to Full got rid of the grey bar entirely.
Click to expand...

Strange, In my case 1/16 rez is giving me the grey bar entirely but 1/8 rez still do not have any grey bar at all... Could it be because I have a redrocket ?
 
Koray Birand said:
Strange, In my case 1/16 rez is giving me the grey bar entirely but 1/8 rez still do not have any grey bar at all... Could it be because I have a redrocket ?
Click to expand...
Could be; I don't have a RR on this PC. Oh yeah, you're on the Mac while I'm running a Windows 7, so that's another difference.
 
Maybe. Also note that going from higher res to a lower res will not always update the histogram.
 
Petri Teittinen said:
Could be; I don't have a RR on this PC. Oh yeah, you're on the Mac while I'm running a Windows 7, so that's another difference.
Click to expand...

Should not make any difference since a histogram is a histogram. Os has nothing to do with it. I do not know if RedCine-X Pro is capable of using ColorSync feature but as far as I tested, no.
Therefore I think this is a bug of RedCine-X Pro. But As Paul said : "At the end of the day, if the image looks good then I'd say there's nothing to worry about"
 
Petri Teittinen said:
It might. Mac and Windows versions of software don't necessarily share the same bugs.
Click to expand...

To be honest I do not have a clue about the Windows side, but as some one earlier mentioned, it is a good idea to compare the histogram of photoshop and redcine to be sure.
 
Anders Holck said:
. . . It does seem that there is some funky stuff going on with the scopes, when the processing is set to a lower res. For example the grey bar will show at 1/4 res but not on 1/1 res without changing the image parameters. I can see from your grabs you are at 1/8 res, try set it to 1/1 instead.
Click to expand...

Props to Anders on catching the software bug in CineX resolving the black information at lower res settings. Going to full seems to reduce the gray bar phenomenon. If RED had a operations manual for CineX they could put that info in there to save users like me a couple days of discovery time. Can anyone tell me how to objectively measure noise in a R3D image/file/frame?

Thank you all for the time and effort!
 
Josh Beadle said:
Props to Anders on catching the software bug in CineX resolving the black information at lower res settings. Going to full seems to reduce the gray bar phenomenon. If RED had a operations manual for CineX they could put that info in there to save users like me a couple days of discovery time. Can anyone tell me how to objectively measure noise in a R3D image/file/frame?

Thank you all for the time and effort!
Click to expand...

I think at the moment you should trust your eye.
 
Eye looking at what specifically? Certainly there has to be an exaggerated view (sliding a adjustment to the extreme) to make noise stand out. Just as there is Edge Focus. Any quick and dirty methods out there to objectively check image quality?
 
Noise changes with contrast and color changes. All of your first grabs seemed very very low contrast, which will tend to make noise less apparent. Some of the grades shown here seem to have a more 'normal' contrast will probably not show much if any noise.

Best way to check noise is to adjust contrast as desired, and watch the result.

Tim
 
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