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  #21  
03-07-2020, 05:45 PM
history1 history1 is offline
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Quote:
The sample does indicate clipping is happening before the capture card. What was the workflow used for the capture? If it was AG-1980 direct to capture card, then the VCR is clipping the bright parts of this tape internally.
The way I have things set up is: AG-1980 > Green AVT-8710 TBC > Capture Device. The camcorder wasn't a very high quality one. That's how it recorded the video. There are quite a few over exposed areas in the tape. I've tried to fix it by keeping within range in the histogram but that doesn't help.
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  #22  
03-09-2020, 01:44 PM
msgohan msgohan is offline
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The AVT-8710 may be what's clipping the overexposed areas. Need a VCR direct to capture card video sample.
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  #23  
03-11-2020, 12:19 PM
history1 history1 is offline
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My AG-1980 was sent to the shop (TGrant) so I only have my regular VCR to plug directly into the capture card. It's not the combo unit, that stopped working. It's a JVC regular unit from 2002. I did a test capture of that one shot you were talking about. It's still overexposed. Like I said, it was recorded that way so I don't think there is anything that can be done. I still have the original Hi8 tape, so I did a test capture from that too, directly from my CCD-TRV138 Hi8 Sony camcorder. It's not the same camcorder the video was shot from. There is no S-Video out on it so I only was able to connect via composite. As expected, still overexposure. Both clips are included right here.

If it helps to why it's overexposed, the video was shot with a Sharp branded camcorder from 2001.


Attached Files
File Type: avi vcr.avi (58.91 MB, 6 downloads)
File Type: avi hi8.avi (64.17 MB, 6 downloads)
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  #24  
03-11-2020, 01:44 PM
traal traal is online now
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Looking at vcr.avi and hi8.avi, there was too much dynamic range in the scene to properly expose both the bright sunlight building outside the window and the relatively dark indoor windowpane at the same time.
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  #25  
03-11-2020, 07:02 PM
Eric-Jan Eric-Jan is offline
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Originally Posted by traal View Post
Looking at vcr.avi and hi8.avi, there was too much dynamic range in the scene to properly expose both the bright sunlight building outside the window and the relatively dark indoor windowpane at the same time.
Also some interlace artifacts.....
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  #26  
03-12-2020, 07:53 PM
history1 history1 is offline
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Also some interlace artifacts.....
AVI files, these ones, are supposed to look like that, I think. It's when they're converted to other formats when the artifacts disappear.

Last edited by history1; 03-12-2020 at 08:15 PM.
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  #27  
03-12-2020, 11:19 PM
msgohan msgohan is offline
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Comparison screenshot with waveform attached as ZIP (too wide for forum).

Some highlights are intact on the VHS copy while the Hi8 cam player is pumping up the levels of the original. But most of what you'd want to see in this shot was never recorded in the first place and isn't correctable, as you say.

The Hi8 cam player is also adding oversharpening artifacts like false darks around the bright windows.


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File Type: zip history1 vcr.avi & hi8.avi screenshot.zip (977.1 KB, 5 downloads)
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  #28  
03-12-2020, 11:45 PM
history1 history1 is offline
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That's weird. You would think this would be the other way around. I didn't think you would get more detail out of a copy than the original, and the copy on VHS was recorded in EP mode, which is lower quality than Hi8.

Maybe it's the low quality that is EP mode that tones down the false darks? I don't see how details could emerge on a copy. One thing I haven't yet mentioned to you is that the VHS copy was recently recorded from the Hi8 camera I currently have, recorded on the very day I uploaded those clips. The VHS clip was not recorded a long time ago from the SHARP camera I owned back then. The false darks were recorded onto the tape, but EP mode probably toned them down a bit.

Last edited by history1; 03-13-2020 at 12:18 AM.
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  #29  
03-13-2020, 03:54 AM
Eric-Jan Eric-Jan is offline
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I guess the original has some/most details, high and low, different things you try to do with it will make different things visible from that,
would be a simple conclusion of that, try different things again only from the orginal material.
But outside of that low - high range, you will not get any information, the scene in question is maybe not a good example because there is not a human face in it, to measure the skin tones, a scene with more color in it, would be better to use.
white is offcourse which has all colors.... but in this scene it is the most over exposed area, which maybe the camera tried to compensate also too much, or not in a good way, due to the quality of a consumer camera, compensating this will be very hard, if not impossible. so you can only improve on that in a limited range.
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  #30  
03-13-2020, 10:00 AM
msgohan msgohan is offline
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Quote:
Originally Posted by history1 View Post
the VHS copy was recently recorded from the Hi8 camera I currently have, recorded on the very day I uploaded those clips. The VHS clip was not recorded a long time ago from the SHARP camera I owned back then.
In that case, I don't understand it either.
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  #31  
03-13-2020, 04:19 PM
history1 history1 is offline
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I also have an old VHS tape that this scene was transferred to back in the day from my old Sharp camcorder. Same thing.
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  #32  
03-13-2020, 09:00 PM
hodgey hodgey is online now
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Analog video recorders will clip the video signal at some set brightness level before encoding it to tape. The signal has to be clipped before being put through the FM-encoding process as one would otherwise end up with horizontal black streaks on playback at white/black transitions when the signal level goes too high. (E.g See this source)

Maybe that's what you're seeing on the recordings. If the recording is overexposed (whether due to bad manual setup or camera auto-exposure not being good enough) the brighter parts may end up being clipped. Same with digital stuff like miniDV for that matter, though in that case it's pretty easy to know if it's from the recording process since the video is all digital.
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  #33  
03-13-2020, 10:01 PM
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Quote:
Analog video recorders will clip the video signal at some set brightness level before encoding it to tape. The signal has to be clipped before being put through the FM-encoding process as one would otherwise end up with horizontal black streaks on playback at white/black transitions when the signal level goes too high.
Are you saying that a VCR that records from a Hi8 camcorder adjusts the brightness levels so that they wouldn't seem so bright after recording? I do notice the levels are a bit better in the VHS version.

I did a little reading in the link you provided and it looks like a VCR can also adjust the dark levels too, so that they wouldn't look so bad, am I correct? This is something that VCRs do, adjust the bright and dark levels so that they become more balanced?
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  #34  
03-14-2020, 07:41 AM
Eric-Jan Eric-Jan is offline
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I guess AGC will have different "limits" on different devices, it's analog, not digital, digital is set to standard values, which most manufactors will value/follow.
Maybe you can use different analog passthroughs to get a better result, but the source material is all what you got, and no magic.
Check if you can do any adjustments in the devices settings/menus.
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