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  #1  
02-20-2020, 05:54 PM
history1 history1 is offline
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Hello everyone. I have made an interesting discovery. I found that videos that play back on my VCR/DVD combo unit (Panasonic DMR-EZ37V) actually show more detail in high-exposed areas than my Panasonic AG-1980. Less exposure is shown which actually reveal more detail. I was playing this VCR out of curiosity to compare the picture with my AG-1980. Does anyone know about this kind of thing? Even though the picture may have improved I would still prefer to use my S-VHS VCR because that's what many people suggest in video capturing. Is there a way I can fix the exposure on my Pro unit to match that of my combo unit, or even better?

I have included a couple of example pictures to show you what I mean.


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File Type: jpeg Combo unit.jpeg (131.3 KB, 40 downloads)
File Type: jpeg S-VHS VCR.jpeg (121.4 KB, 40 downloads)
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  #2  
02-20-2020, 06:50 PM
BarryTheCrab BarryTheCrab is offline
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Actual video files, unprocessed, I think would be preferable.
That being said I see more red color bleeding from the woman’s dress, down on the right side, in the Svhs jpeg.
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  #3  
02-21-2020, 09:49 AM
hodgey hodgey is offline
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There are trim-pots insinde the VCR that adjust the Y level, though I woudln't recommend messing with them unless you know the level is higher than it's supposed to be. You should be able to adjust the level on the capture card side (or tbc). The AG1980P does also have some image settings to adjust sharpness and noise reduction - probably someone that uses these can fill you in on how to set it.
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  #4  
02-21-2020, 03:51 PM
history1 history1 is offline
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My TBC (AVT-8710) won't correct the levels in a way that more details show up. Adjusting the levels on that only brightens/darkens the picture, nothing else. Same thing with levels in software (VirtualDub). The problem lies within the VCR (those trimpots you were talking about). Is it easy to access them so I wouldn't damage the VCR (AG-1980)?
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  #5  
02-23-2020, 11:52 AM
traal traal is offline
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What capture card are you using with the AG-1980? In VirtualDub you need to adjust brightness and contrast so the video levels fit within the blue area of the histogram. Does that fix the overexposure?
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  #6  
02-23-2020, 12:03 PM
Eric-Jan Eric-Jan is offline
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What i notice from these pictures, is the inperfection of the vertical lines, at one picture....
which means the video signal is too strong ?
I guess you should go for the combo, and move on, i've seen worse captures....
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  #7  
02-23-2020, 02:06 PM
hodgey hodgey is offline
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It looks like the TBC in the AG1980P is off at least.
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  #8  
02-23-2020, 03:41 PM
Eric-Jan Eric-Jan is offline
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You could also use the Intensity Shuttle with the Panasonic DMR-EZ37V because the Panasonic DMR-EZ37V has also component video output, which you also can switch to progressive output, check the manual for this.
This way you can set (the capture) video levels in the video setup driver settings, or in post with Davinci Resolve, works perfect.

(the DMR-EZ37V already gives a better and clean video signal output, it looks very much alike the DMR-ES35V)

btw. you did not tell which capture device you use, it's important

Last edited by Eric-Jan; 02-23-2020 at 03:51 PM.
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  #9  
02-23-2020, 04:47 PM
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Quote:
Originally Posted by Eric-Jan View Post
you also can switch to progressive output,
This will result in far less detail, not more, as it requires deinterlacing (and not a good method, either).

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  #10  
02-23-2020, 05:47 PM
Eric-Jan Eric-Jan is offline
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Quote:
Originally Posted by lordsmurf View Post
This will result in far less detail, not more, as it requires deinterlacing (and not a good method, either).
Why ? i only can find info, that component video output (also de-interlaced, with this EZ37V model available) is better then s-video or composite video, in anyway ...never worse.
de-interlacing will always give less detail, anyway ?
A side effeect of component progressive output is also, that it removes Macrovision (if present on tape) i noticed.

Last edited by Eric-Jan; 02-23-2020 at 06:02 PM.
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  #11  
02-23-2020, 06:02 PM
history1 history1 is offline
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Quote:
What capture card are you using with the AG-1980? In VirtualDub you need to adjust brightness and contrast so the video levels fit within the blue area of the histogram. Does that fix the overexposure?
I am using an AIW 9800 Pro.

I have already tried adjusting the brightness and contrast, as well as putting it in range of the histogram, and that doesn't work.

Quote:
You could also use the Intensity Shuttle with the Panasonic DMR-EZ37V because the Panasonic DMR-EZ37V has also component video output, which you also can switch to progressive output, check the manual for this.
This way you can set (the capture) video levels in the video setup driver settings, or in post with Davinci Resolve, works perfect.

(the DMR-EZ37V already gives a better and clean video signal output, it looks very much alike the DMR-ES35V)
I don't have that unit. Right now I'm just going to try to use the AG-1980P. It's highly suggested, and I already have it. Many people use it, and I don't think many people would if there is an exposure issue. I think there's some sort of problem with it. Maybe a caps issue? I am already planning on sending the unit to TGrant Photo so they can look at the caps, the unit already has other problems.
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  #12  
02-23-2020, 06:09 PM
Eric-Jan Eric-Jan is offline
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Quote:
Originally Posted by history1 View Post
I am using an AIW 9800 Pro.

I have already tried adjusting the brightness and contrast, as well as putting it in range of the histogram, and that doesn't work.



I don't have that unit. Right now I'm just going to try to use the AG-1980P. It's highly suggested, and I already have it. Many people use it, and I don't think many people would if there is an exposure issue. I think there's some sort of problem with it. Maybe a caps issue? I am already planning on sending the unit to TGrant Photo so they can look at the caps, the unit already has other problems.
The AIW 9800 Pro has also component video input
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  #13  
02-23-2020, 06:19 PM
hodgey hodgey is offline
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Quote:
Originally Posted by history1 View Post
Maybe a caps issue? I am already planning on sending the unit to TGrant Photo so they can look at the caps, the unit already has other problems.
Not impossible, I had issues with blown out video and other things on a Panasonic AG5700, replacing certain caps and adjusting some gain pots improved it (though haven't completely figured out other issues.) May even be more plausible on a 1980P due to the video path involving digitization (which could result in clipping and other issues if things are off with the VCR).
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  #14  
02-23-2020, 06:22 PM
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Quote:
Originally Posted by Eric-Jan View Post
The AIW 9800 Pro has also component video input
Why do you insist on component (Y+Cr+Cb), from an analog tape format that is Y+CrCb, and can use s-video (Y+CrCb). What is the purpose of it? You gain nothing. In fact, you limit your workflow options. As well as introduce potential crosstalk issues by switching carrier cables.

It makes no sense.

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  #15  
02-23-2020, 06:38 PM
hodgey hodgey is offline
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If you're grabbing the processed output from a DVD-Recorder it may give a marginal quality improvement over S-Video, especially for PAL as it would avoid doing vertical chroma smoothing done in PAL a second time by the capture card. It may evade macrovision, or may make it worse, as component doesn't support all forms of macrovision. Granted, DVD-recorders tend to screw up the image when seeing copy protection in any case.

The raw video on vhs (and video8,betamax etc) is Y/C and not component so any component output will have had to go through a chroma decoder, and most likely a digitization step.
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  #16  
02-23-2020, 11:45 PM
history1 history1 is offline
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I think I found out why the combo shot is less exposed than the SVHS one, and if so there is no problem at all with my pro unit. I had captured test shots of the same scene with both units. The thing is, when I advanced each test shot frame by frame to the subject presented in this post, I tried to match to the exact frame on both shots, but actually couldn't match them to a tee. It's a movement shot, so the exposure/details fluctuate as I move. Since both frames are not at the exact location of the shots, the exposure is a tad different between each frame. I just tested this out and found it to be true.

Last edited by history1; 02-24-2020 at 12:09 AM.
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  #17  
02-25-2020, 01:41 PM
history1 history1 is offline
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Quote:
I had captured test shots of the same scene with both units. The thing is, when I advanced each test shot frame by frame to the subject presented in this post, I tried to match to the exact frame on both shots, but actually couldn't match them to a tee. It's a movement shot, so the exposure/details fluctuate as I move. Since both frames are not at the exact location of the shots, the exposure is a tad different between each frame. I just tested this out and found it to be true.
I found out that this is not the reason why the exposure is different for each of those frames. I've been doing more experimenting, and have test captured the same scene multiple times with only the AG-1980. At the same frame as above the exposure is different for each take. I think it's a caps issue after all.
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  #18  
02-25-2020, 08:00 PM
msgohan msgohan is offline
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As noted way back in post #2, we need short, unprocessed video samples attached.

As hodgey said, the AG-1980 line TBC appears to be turned off in the post #1 screenshot. Or it's not working properly.

Quote:
Originally Posted by history1 View Post
I've been doing more experimenting, and have test captured the same scene multiple times with only the AG-1980. At the same frame as above the exposure is different for each take. I think it's a caps issue after all.
Maybe. Did you give the capture card's AGC enough time to settle? If you just did FF/RW directly to the desired spot, AGC can cause differing levels. You need to seek to a bit before the comparison scene each time.
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  #19  
02-26-2020, 05:06 PM
history1 history1 is offline
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Quote:
As noted way back in post #2, we need short, unprocessed video samples attached.
Unfortunately my combo unit just stopped working. I was able to get a raw avi from my AG-1980P of that scene but wasn't able to get a copy from my combo unit. The tape is now stuck in there and I can't get it out.

Quote:
Maybe. Did you give the capture card's AGC enough time to settle? If you just did FF/RW directly to the desired spot, AGC can cause differing levels. You need to seek to a bit before the comparison scene each time.
No I didn't. I did let it settle before the new capture I did today, but comparing that with the images I have from past captures with the AG-1980 the exposure level is still the same. I used the timing graph of VirtualDub to see when the tape had relaxed enough for a capture, capturing only when the lines all merged together. I hope I did it right.

Quote:
As hodgey said, the AG-1980 line TBC appears to be turned off in the post #1 screenshot. Or it's not working properly.
It was turned off, I had discovered. The capture I did today was made when the TBC was turned on.

Here attached is the capture I did today. The painting shot I got the snapshots from is at the very end.


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File Type: avi SVHS.avi (71.44 MB, 9 downloads)
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  #20  
03-07-2020, 04:31 PM
msgohan msgohan is offline
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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.

Quote:
Originally Posted by history1 View Post
I did let it settle before the new capture I did today, but comparing that with the images I have from past captures with the AG-1980 the exposure level is still the same. I used the timing graph of VirtualDub to see when the tape had relaxed enough for a capture, capturing only when the lines all merged together. I hope I did it right.
I don't think the timing graph would really relate to the idea I was referring to. But the sample does include enough "pre-roll" before the painting shot, regardless.
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