Welcome to our community

Be a part of something great, join today!

Log in
  • 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 :)

Redcine-X Histogram not correct?

K

kevin nations

Member
Joined
Jul 8, 2013
Messages
11
Reaction score
0
Points
0
Location
Texas
I am on a job and just received footage. Looking at these shots, its obvious that some of the highlights are over exposed and blown out to the point where there is lost information. However, when I look at the histogram, it is not slammed up against the side with a raised goal post. Shouldn't it be?

Any thoughts on why this might be happening? Forgive me if this is a dumb question.

-
kevin
 
Bob: I am not sure I have permission to post this footage. Instead, here is a still frame of what I am talking about. I denoted on the frame grab the areas that are blown out. If I try and adjust look settings, there is absolutely no definition in these areas and I can't pull any detail out of it. By looking at the WAVEFORM, it does appear there are FLAT sections that agree with my blowout theory, but I am perplexed as to why the HISTOGRAM isn't looking the way I think it should.

Stacey: Maybe? I am using iMac 27" retina

http://www.nationsunderground.com/ClippingExample.png
 
It's hard to say for 100% certain without having the R3D to play with, but to my eye, what's happening is that the footage itself is clipped, but the ISO and/or exposure and/or FLUT and/or Gain is knocked down enough that the stuff that's clipped is below 100 IRE; remember that the Histogram and Waveform in RCX is dynamic, meaning that as you adjust the sliders for the metadata, the Histogram and Waveform change with the changes. If you take a look at the Histogram, that last peak on the right is very sharp, both before and after. If you take a look at the Waveform monitor that corresponds with that part of the image, that to me looks like peaking/clipped footage. A hair fuzzy around that top line, probably due to the metadata adjustments that have been made, but still, peaking. Note how there's NOTHING above it, either for the section peaking on the left of frame or on the right of frame. It just flatlines around 87 IRE.

The skintones look good. But those clipped sections look clipped.
 
Get on the latest release build of RCX.
the dry slider should take care of this
what camera FW are they on?
If you have pulled back the ISO then it might still be clipped. Is this "as shot" or did you pull back the ISO in RCX?

Anyway, all things to check on.

battistella
 
Check to see if the Gain slider is adjusted. The camera would state that this is clipping however, you can lower the value in Redcine-X Pro to be below clip. A .R3D snapshot and RMD would be useful to really see what's up. I guarantee the camera was illuminating the Stop Lights and the highlight Goal Post was filled a bit.

*edit, Kevin. PM or email me off the air and I'll take a look.
 
You must log in or register to reply here.
Back
Top