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1. Re: Waveform IRE Level Over 100 on Sony A77 but not for Canon T2i
Jeff Bellune Nov 9, 2011 3:50 AM (in response to Dave Dugdale)My guess for the clipped highlights in the MOV file is the format itself, or Premiere's custom 64-bit MOV importer.
Look at the images (not the waveform) in the Sony monitors vs. the images in the Pr monitors: a visual check of the lost highlight information in the MOV file looks about the same.
If you examine the waveforms in the Sony monitors, you'll see that the MOV file is severely clipped compared to the MTS file. It's just clipped at at a higher IRE than in the Pr monitors.
Finally, the skin tones in the Sony waveform monitor for the MTS file max out at about 65 IRE, but the MOV skin tones max out at about 75 IRE. In the Pr monitors they both max out at about 70 IRE.
It's seems that the Sony monitors are showing the same info as the Pr monitors, just on a slightly different scale.
-Jeff
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2. Re: Waveform IRE Level Over 100 on Sony A77 but not for Canon T2i
SteveHoeg Nov 9, 2011 4:59 AM (in response to Jeff Bellune)We've worked with Canon on how to interpret their DSLR footage, and they are a bit unusual in that they shoot full range YUV. This means instead of leaving padding at each end for superwhites and superblacks they stretch out to use all values. Many popular video applications are still getting this wrong assuming Y' goes from 16-235 here instead of 0-255 and you will often be able to notice visible brightness differences where this is being handled wrong.
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3. Re: Waveform IRE Level Over 100 on Sony A77 but not for Canon T2i
Jeff Bellune Nov 9, 2011 5:31 AM (in response to SteveHoeg)Good info, but for me, one point still needs clarification: are you saying it's Vegas that's assuming Y' as 16-235?
Thanks,
-Jeff
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4. Re: Waveform IRE Level Over 100 on Sony A77 but not for Canon T2i
Dave Dugdale Nov 9, 2011 6:17 AM (in response to Dave Dugdale)Thanks everyone for replying, here is a some more info from the two video clips that might help (meta data):
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This is from the Canon T2i:
Video:
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Baseline@L5.0
Format settings, CABAC : No
Format settings, ReFrames : 1 frame
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 29s 654ms
Bit rate mode : Variable
Bit rate : 32.9 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Original height : 1 088 pixels
Display aspect ratio : 16:9
Original display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.661
Stream size : 116 MiB (96%)
Language : English
Encoded date : UTC 2011-11-08 13:05:09
Tagged date : UTC 2011-11-08 13:05:09
Color primaries : BT.709-5, BT.1361, IEC 61966-2-4, SMPTE RP177
Transfer characteristics : BT.709-5, BT.1361
Matrix coefficients : BT.601-6 525, BT.1358 525, BT.1700 NTSC, SMPTE 170M--------------------
This is from the Sony A77:
Video
ID : 4113 (0x1011)
Menu ID : 1 (0x1)
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.0
Format settings, CABAC : Yes
Format settings, ReFrames : 2 frames
Format settings, GOP : M=1, N=12
Codec ID : 27
Duration : 28s 987ms
Bit rate mode : Variable
Bit rate : 20.9 Mbps
Maximum bit rate : 22.0 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.420
Stream size : 72.1 MiB (95%) -
5. Re: Waveform IRE Level Over 100 on Sony A77 but not for Canon T2i
JSS1138 Nov 9, 2011 8:02 PM (in response to Jeff Bellune)are you saying it's Vegas that's assuming Y' as 16-235?
I read it that way myself. But clarification would be nice.
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6. Re: Waveform IRE Level Over 100 on Sony A77 but not for Canon T2i
SteveHoeg Nov 10, 2011 4:16 AM (in response to JSS1138)I don't have a copy of Sony Vegas to test, but you can find some information about this online. Note that this article is somewha old and at that point (CS4) Premiere Pro was also incorrectly interpreting these files.
http://cineform.blogspot.com/2009/01/full-dynamic-range-video-from-canon-5d.html
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7. Re: Waveform IRE Level Over 100 on Sony A77 but not for Canon T2i
Dave Dugdale Nov 10, 2011 7:04 AM (in response to SteveHoeg)Thanks Steve, that link had a lot of great info in it.
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8. Re: Waveform IRE Level Over 100 on Sony A77 but not for Canon T2i
Dave Dugdale Nov 10, 2011 10:35 AM (in response to Dave Dugdale)If anyone is interested more about this issue I talk about it in my latest video:







