Pixel Format: Video Levels or Full Range
by Useph George on Nov 13, 2009 at 9:28:23 pm
Got a canon HF S100 camcorder. It produces AVCHD files on an SDHC card.
Does anyone know how I can tell if the 8bit rgb range is 0-255 or 16-235? I dont want a visual verification. I would like something that writes min blue val = 0, max blue val = 255 or min blue val = 16 and max blue val = 235 - or something similar. I have written to canon. All canon has to say is that its not documented.
Does the x.y.color camcorder setting change the range?
does setting the sony vegas project properties video levels change the pixel/rgb values on the preview screen. Ie if a file rgb ranges of 0-255, does setting the project properties to "video settings" clip the 0-255 values, or does it compress the range.
The canon camcorder has the ability to create color bars and test tone. I can also record this test pattern onto an SDHC card. When I download the recorded test pattern, copied it to the vegas pro clipboard, and pasted the image to adobe photoshop elements, I can see the rgb values of the color bars. When I do this I get a bit confused as to whats going on.
What do the Vegas Vectorscope readings tell you? What does the waveform monitor tell you?
When copying from Vegas to Photoshop, you're compressing the image and converting the file, therefore potentially skewing your result.
Image should be 0-255, but I don't know that camera, it may be 16-235, might be 0-255. View the exported bars in Vegas.
RGB = 0-255 color range
sRGB = 16-235 color range (aka, studio RGB)
XY doesn't change the range, it changes the depth of color.
Douglas Spotted Eagle
Certified Sony Vegas Trainer
Re: Pixel Format: Video Levels or Full Range by Useph George on Nov 14, 2009 at 5:35:01 pm
Thanks for the reply.
Using "full range", the video scopes:histogram (luminance/r/g/b) shows the values 0-255
Using "video levels", the video scopes:histogram (luminance/r/g/b) shows the values 0-238 ( mostly - Mostly the values near 255 shifted to lower values. values near 0 did not nearly shift as much. )
What I also learned is that the "digital" "color bars" do not appear to be so perfect when displayed on the various vegas video scopes. For video scopes:vectorscopes there are 2 dots in each of the B/G/Y/R boxes. Mg/Cy boxes have only one dot. The Histogram for the R/G/B values are all different.