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  #1  
03-01-2013, 10:07 PM
JasonCA JasonCA is offline
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In this case, I'll stick with the "no question is too dumb" philosophy.

But, I was wondering if someone could comment on a single capture being able to capture the full color dynamic range of VHS?

Considering VHS is analog, does a single capture card (say ATI USB 600 through S-Video) capture the full dynamic range of colors for the VHS signal in ONE pass (assuming a proper setup where the color levels fall within the proper NTSC ranges of the histogram)? In other words, could the sampling of the VHS signal not fully sample the full spectrum of colors for a VHS signal?

This sort of leads into my other similar question. I've heard a lot about how Elite Video's BVP-4 Plus can boost the resolution of the video. I don't quite understand how that is possible? I've read the BVP-4 plus has a "increased resolution (1200 lines vs. 800) and signal-to-noise ratio (68dB)". Since the BVP-4 seems to enhance the resolution and perhaps even the colors, I was wondering if perhaps capturing video without using the BVP-4 could reduce the dynamic range of colors that is being captured by a capture card?

Therefore, is having a BVP-4 in the loop of your capture (even if you don't really drastically adjust the knobs; leaving them in their defaults) help to enhance the resolution of the video prior to it entering the capture card?

I suppose I'd like to convince myself that a single pass of the VHS with a capture card does indeed capture the entire video signal? In other words, am I sucking out the full quality of the VHS signal in a single pass of VHS into my capture card and getting all their really is to get? (Yes, I know having a TBC is important to have in this loop too as well as a good VCR for a good capture).

As a side note only (if someone wants to additionally answer this), an alternative to the ATI 600 USB is the professional "Aja Kona LHi-LHe-LSe HD/SD 10-bit Digital and Analog PCIe capture card series" which is roughly $1000+ dollars. Is there really any improvement as far as quality in capturing with a Aja Kona over the ATI 600 USB? Higher raw uncompressed bit-rate? Maybe 10-bit Aja Kona vs 8-bit ATI 600 USB (I don't really know what the bit-rate is for the ATI 600 USB)? Why should anyone bother with a Aja Kona when the ATI 600 USB is much cheaper and still available?
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  #2  
03-02-2013, 10:22 AM
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lordsmurf lordsmurf is offline
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When you're talking about dynamic range, you're talking about bit depth. VHS color is so crappy (by modern standards) that even 6-bit dithered processing could get it all. For sure 8-bit can, and is what may cards are. Most other sources are also adequately captured at 8 bits. Anything higher can too, but isn't required.

Resolution boosting is an optical illusion. It's a trick. Now, that's not bad, it just fool's our eyes. The Elite BVP4+, as an example, puts the NTSC lines of resolution into a bigger palette to process. Then it augments the signal by giving it false contrast -- placing white pixels by dark ones. But there's trade-off in the signal, and it does lose that "archival" value.

Aja is a better card, but you won't see that with VHS tapes. Something like that is intended for better formats, like BetacamSP.

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  #3  
03-03-2013, 03:00 AM
JasonCA JasonCA is offline
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Quote:
Originally Posted by lordsmurf View Post
When you're talking about dynamic range, you're talking about bit depth. VHS color is so crappy (by modern standards) that even 6-bit dithered processing could get it all. For sure 8-bit can, and is what may cards are. Most other sources are also adequately captured at 8 bits. Anything higher can too, but isn't required.

Resolution boosting is an optical illusion. It's a trick. Now, that's not bad, it just fool's our eyes. The Elite BVP4+, as an example, puts the NTSC lines of resolution into a bigger palette to process. Then it augments the signal by giving it false contrast -- placing white pixels by dark ones. But there's trade-off in the signal, and it does lose that "archival" value.

Aja is a better card, but you won't see that with VHS tapes. Something like that is intended for better formats, like BetacamSP.

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Great to hear from you Lordsmurf....really! It helps yes!

What about the shadow detail that is lost on a straight capture (or what seems to be lost)? For instance, if I did one single capture (without a BVP) using my ATI USB 600, I may not see objects that may actually exist in dark areas when the video is captured. However, when using the Elitevideo to adjust the video prior to it being captured, I can make an object that was dark more visible and perhaps see an object that was otherwise hidden in a dark area of the video. Is this a trick of the eye?

That leads to the question ... if I didn't have a BVP prior to capturing in the loop, would I have ever been able to adjust the video in post editing to see the object that was hidden in the dark area? Perhaps a bit complicated to explain, but I think you understand what I am asking.

So I'm trying to grapple with how do I know I'm pulling ALL the color and video from the VHS tape? And, I'm trying to grapple with if a single pass through the capture card really does grab all that detail in the VHS video that could possibly be seen?

Can you explain what you mean by this:

Quote:
Originally Posted by lordsmurf View Post
But there's trade-off in the signal, and it does lose that "archival" value.
It begs me to question: how does one know when it's good to use the Elite Video BVP for capturing? If having the Elite Video in the capture loop affects the "'archival' value", then why use it? And if what can be done with the Elite Video can be done in post editing, again why use the Elite Video? If I'm really capturing all the video in a single pass (the full dynamic range of colors) and all of that good stuff exists in the data stream, then I don't see why I couldn't post edit the video to do the same thing that I could have otherwise done with the Elite Video prior to it being captured?

Is it just that the Elite Video is great at fooling the eyes prior to the video stream being captured? Or maybe, the Elite Video helps to reduce the complexity that it otherwise would have taken to do in post editing software to accomplish the same thing? Or, what if I used the Elite Video as simply a pass thru device: benefit from the so called "increased resolution (1200 lines vs. 800)" but leave all the knobs in their default positions to not really alter the video? Anything gained?

I sometimes feel like I must capture the video twice: The first time, to just have a straight normal capture. And the second capture, to use a BVP to see detail in dark areas that I would have otherwise not have seen in straight unmodified capture.

Quote:
Originally Posted by lordsmurf View Post
Aja is a better card, but you won't see that with VHS tapes. Something like that is intended for better formats, like BetacamSP.
Again a bit off of my original topic, but I am curious about this too in regards to the AJA card. Apparently, you can upscale the VHS video for HD for perhaps viewing on a HD TV. From what I have read in the forums, it seems it's still better to capture VHS in a standard format (740 x 480) at the best quality you can get (good VCR, good TBC, and good capture card). Then, using software I could then later upscale the (740x480) video for viewing on a HD TV. Wouldn't that be equivalent to having done the up-scaling in hardware with the AJA card? Really where does up-scaling start in terms of VHS? For all I know, 740 x 480 is perhaps already a bit up-scaled too for VHS (isn't NTSC VHS roughly equivalent to 333x480 pixels of luma and 40x480 of chroma). But, it seems 740 x 480 is regarded as the standard for VHS capture. Will capturing of VHS in 740x480 remain as the standard in the future?

Sure, in the future, VHS may look pretty lousy on a HD TV. But, I would hate to question to myself, "Ohhh, if I used an AJA card, it would have looked better" .
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  #4  
03-03-2013, 10:30 AM
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It's not "lost" detail in shadows. VHS simply doesn't reproduce shadows/darks/blacks very well. The BVP4+ is able to bring it out, however. The tape plays like "blah" whether it's into a VCR/TV or capture card.

Use it when it makes the picture better, period. Don't when not.

Restoration is about making it better, not perfect. If you add one smaller error, but can remove several larger ones, that's a success.

Not everything can be done in software. The Elite Video BVP4+ is not replaceable in software. Different, yes. You can do step 1 is the BVP4+, and do more step 2 in software, too. Sometimes the Elite is better, sometimes software is better. There's no one answer.

Be sure your monitor/TV is color calibrated if you're darkening videos like that.

Upscaling is useless. Capture SD as 720x480 max. That'll always be the standard.

No, that AJA card won't help. The grass isn't greener.

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  #5  
03-03-2013, 02:24 PM
JasonCA JasonCA is offline
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Quote:
Originally Posted by lordsmurf View Post
It's not "lost" detail in shadows. VHS simply doesn't reproduce shadows/darks/blacks very well. The BVP4+ is able to bring it out, however. The tape plays like "blah" whether it's into a VCR/TV or capture card.

Use it when it makes the picture better, period. Don't when not.
So what's going on then? You said VHS doesn't reproduce the shadows/darks/blacks very well? But if the shadows/darks/blacks or detail do exist, it still must come from the VHS tape.

This to me means the signal is weak when going straight from the VHS to the capture card without a BVP4+. So when the capture card samples the video, it can't pull from that weak signal that detail that is truly there? But, if you add the BVP4+ prior to it entering the capture card, the BVP4+ can boost those weak signals to send into the capture card? The capture card, then can better sample the shadows/darks/blacks much better?

That's sort of my understanding of why this can really only be done by the BVP4+ and NOT done in software.

Sound about right?

Quote:
Originally Posted by lordsmurf View Post
Restoration is about making it better, not perfect. If you add one smaller error, but can remove several larger ones, that's a success.

Not everything can be done in software. The Elite Video BVP4+ is not replaceable in software. Different, yes. You can do step 1 is the BVP4+, and do more step 2 in software, too. Sometimes the Elite is better, sometimes software is better. There's no one answer.
The BVP4+ sounds like it's a genius at manipulating parts of the signal so that the capture card can better sample it to pull out detail that otherwise could not have been pulled out without the BVP4+.

Quote:
Originally Posted by lordsmurf View Post
Be sure your monitor/TV is color calibrated if you're darkening videos like that.
Will do! I'm learning to use the waveform more though too.

Quote:
Originally Posted by lordsmurf View Post
Upscaling is useless. Capture SD as 720x480 max. That'll always be the standard.
Good to know! 720x480 max it is. Hear that everyone? Capture VHS as SD 720x480 and later upscale the video in the future....it's as good as it gets.

Quote:
Originally Posted by lordsmurf View Post
No, that AJA card won't help. The grass isn't greener.
Yes, I'm trying to save the water! No point in standing there trying to water it while you are staying me and thinking I'm knowing the AJA card won't improve a thing in terms of up-scaling is concerned.
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  #6  
03-03-2013, 02:42 PM
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kpmedia kpmedia is offline
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The VHS is weak, yes. And it takes a BVP4 to pull it out, or fudge it (fake). Usually both. Any proc amp works that way.

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  #7  
03-03-2013, 05:56 PM
JasonCA JasonCA is offline
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Quote:
Originally Posted by kpmedia View Post
The VHS is weak, yes. And it takes a BVP4 to pull it out, or fudge it (fake). Usually both. Any proc amp works that way.
Thanks kpmedia!

I still don't know if I believe it to be 'fake' though? The VHS is weak, but what exists in the VHS signal exists regardless if it's weak or not. The BVP+, I would hope, doesn't ADD things to the video...only enhances it. I perceive the BVP4+ has the ability to boost that signal so that the capture card can see it beyond thinking it's noise. So the BVP4+ must be a good at manipulating those signals in a way that enhances certain areas within a frame of video to bring out the detail. So would you really call that fake when a BVP+ only enhances or manipulates what already exists?

For me this is interesting, because I'm trying to understand the purpose of why things must be done PRIOR to the video entering the capture card? And why it can't be done simply in post editing?

Discussing this helps....even if I fully don't understand it like others can.
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  #8  
03-03-2013, 08:10 PM
NJRoadfan NJRoadfan is offline
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It sees noise.... and attempts to "sharpen" it. Some things are easier to fix in the analog domain vs. digital. If you are crushing whites and blacks (anything above 235 and below 16), you lose it with a capture card since the information was never recorded to begin with.
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The following users thank NJRoadfan for this useful post: kpmedia (03-12-2013)
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