TBC Image Quality Thread (pics)

[mike1061]

Thanks for all your work on this.
Mike

[thecoalman]

I'm using a pretty good mointor here so details show up pretty good. Giving it the eyeball test I see little difference between the first set of samples from brainstorm. About the only difference I see is the one JohnFulci pointed out. Cole's on the other hand I can see there's a slight loss in detail.

I know Junkmalle pointed out the difference when enlarged but much of that could be exacerbated by the jpeg compression. I'd suggest providing alternative images in a uncompressed format...

I have a JVC 9800 with a Built in TBC, does this count as a TBC.

I don't think that applies here because of the additional filtering by the DNR, also they're using DVD's as the source.

[Cole]

What people seem to forget is that by the time you encode this to an MPEG, and view it on a normal tv set (or even something larger and/or fancier), at a normal viewable size, all of the talks of lost detail pretty much become moot. This sort of "lab test" on a small computer screen with test patterns is already at the point of being either imagination, or so minute that it doesn't get notice by at least half of the people involved.

Ultimately the final image has got to be watchable, but in the processes of this forum the emphasis is very much on getting the best quality picture that one can; but Lordsmurf is right: at the end of it all, looking good on a television is the ulitmate goal. Sitting up against a television screen watching for picture softening isn't going to happen!

Each piece of equipment I have purchased so far has been to solve a particular issue: JVC 7965 to clean up the chroma noise and the Datavideo TBC-100 to solve syncronisation problems. As a result, I am now quite confident that I am still getting a clean playback without any missing frames or freezes.

The only real upgrade left on my current system is better cables, which may help the situation.

[edDV]

Interesting thread. I still don't have a TBC except the one built into my Sony R-1000 SVHS deck.

For as much as people have insisted VHS is a format that separately records luma and chroma, it really does give off the appearance that it's a composite "merged" signal. Or at very least, a sloppy separation that bleeds into one another. It takes a good VCR with a nice Y/C comb filter, maybe even a line TBC with some DNR, to prevent messy stuff like shown in the images.

A normal home VHS VCR has a composite input (external or internal tuner) that needs to be bandpass filtered before recording. Luminance is low pass filtered below 3MHz and chroma is notch filtered around 3.58 MHz (NTSC) and 4.43 MHz (PAL). Since a notch filter is used for color extraction instead of a comb filter, luminance near subcarrier frequency is picked up in the process. This luminance leakage is what produces the cross-color (false color patterns).

Some S-VHS recorders have a comb filter to separate chrominance from the composite signal leaving luminance out to 4+ MHz and separate chrominance which is downconverted 629KHz for recording.

This is a good summary of the formats http://catalogs.infocommiq.com/AVCAT/images/documents/pdfs/TT189%20-%204611.pdf.

[davideck]

What does anyone think about this?

I think if it's that noticeable, you should buy a detailer and insert it after the TBC. It'll be good for not only counteracting what you think is softer there, but it can even surpass the sharpness of the source.

The "Edit" Mode on my JVC HR-S6800 SVHS VCR provides an effective means for counteracting this softening BEFORE it takes place. The use of detailers, enhancers, etc. AFTER the softening can be a slippery slope along the fine line between restoration and alteration.

This sort of "lab test" on a small computer screen with test patterns is already at the point of being either imagination, or so minute that it doesn't get notice by at least half of the people involved.

I seem to have struck a nerve with my original post in this thread. I am not suggesting that DataVideo TBCs are BAD, or that their softening effect is significant. It is subtle, but it is real. It may actually HELP the MPEG encoding process, and as BrainStorm69 has noted, there may be more to it than just high frequency response.

Some people have a more critical eye than others. If half of the people don't notice this softening, then that suggests that the other half do. That sounds about right...

[BrainStorm69]

What people seem to forget is that by the time you encode this to an MPEG, and view it on a normal tv set (or even something larger and/or fancier), at a normal viewable size, all of the talks of lost detail pretty much become moot. This sort of "lab test" on a small computer screen with test patterns is already at the point of being either imagination, or so minute that it doesn't get notice by at least half of the people involved.

LS, you're probably right from a practical standpoint, but for some reason (probably the silly perfectionist streak in me), I still would like to capture the absolute best image I can for conversion to DVD. Perhaps the little things shown by various threads like this regarding image quality of various aspects of capturing (different vcrs, different TBCs, different detailers, different proc amps, different capture devices, etc.) are unnoticeable each by themselves, but maybe when you add them all up, they do make a noticeable difference in the end DVD. Or perhaps in the end, it is trying to count the number of angels on the head of a pin, but these sorts of threads still are very interesting to me.

For those that want to see uncompressed images because they think the jpeg format is causing compression artifacts, here are the original uncompressed .tga files straight from VDubMod. My experience has been that as little jpeg compression as I'm doing, the jpeg images are pretty darn accurate.

notbc-dvd.zip

tbc-dvd.zip

notbc-svhs.zip

tbc-svhs.zip

[lordsmurf]

Some people have a more critical eye than others. If half of the people don't notice this softening, then that suggests that the other half do. That sounds about right...

Well, I have a pretty good eye for photos and video, have for years now. But I cannot get past the point of mix-up and re-identification. Meaning, if I save thse images to my drive (the JPEGs, not looked at uncompressed yet), and get somebody else to randomly rename them, and randomly copy each of them a few times and give those a new name too, I cannot look at them and say "oh yeah, this one is definitely sharper".

[BrainStorm69]

BTW, I'd still like to encourage all of you who have different TBCs to participate in this thread with comparative screen shots. I'd especially like to see some sorts with the AVT-8710 since I've seen claims by some that it provides a "cleaner" image than the Datavideo TBCs.

[Cole]

The "Edit" Mode on my JVC HR-S6800 SVHS VCR provides an effective means for counteracting this softening BEFORE it takes place. The use of detailers, enhancers, etc. AFTER the softening can be a slippery slope along the fine line between restoration and alteration.

I don't appear to have that function on my JVC HR-S7965, but in case I am being a bit thick, I have posted the menu below.



The "picture control" can be set to "Edit". Is that the setting that you mean?

[davideck]

The "picture control" can be set to "Edit". Is that the setting that you mean?

Yes. There might also be a "sharp" selection.

You could also try turning OFF the TBC/NR to see if this system is causing any softening or reducing the effects of the picture control.

[Cole]

The "picture control" can be set to "Edit". Is that the setting that you mean?

Yes. There might also be a "sharp" selection.

You could also try turning OFF the TBC/NR to see if this system is causing any softening or reducing the effects of the picture control.

I ran a test on several combinations of settings on the JVC's menu and the better set up was TBC/DNR on, B.E.S.T. on, and Picture Control set to (as you advised) Edit. Thanks for the nod.

[lordsmurf]

EDIT mode is really nothing more than turning off all filters. Sort of ruins the point of having a JVC S-VHS unit.

[Cole]

But having the the TBC/DNR still set to on, isn't this still operational?
I take it from this, that the Picture Contol should stay on auto as this will be best for all types of video.

[davideck]

EDIT mode...Sort of ruins the point of having a JVC S-VHS unit.

I disagree.

http://www.totse.com/en/media/cable_and_satellite_television_hacks/edmode.html

The function of edit switches (in general) is this:

In playback, most VCRs add a certain amount of edge "emphasis" to make the
picture appear subjectively sharper. In S-VHS VCRs, they also "average" chroma
information over several lines to reduce noise. Unfortunately, this causes
chroma displacement vertically, and makes the color appear to be sliding down
the screen.

Turning "on" the edit mode switches out most of the extra emphasis, as well as
reducing the number of "averaged" lines, which helps makes subsequent dubs look
a little better.

Some folks (myself included) find that the machine looks BETTER with the edit
mode engaged all the time. It produces a more technically correct picture in
that mode, though with a slight noise penalty. My best advice is to try
switching it on and off while carefully observing the playback image, and
decide which you like best. It has no function during record.

[lordsmurf]

TBC/DNR is separate from the other image quality filters that EDIT controls.

[vhelp]

Evening all.

Here is my experience, coming from a JVC S-VHS HR-S3910U older
generation model.. my eyes tell me the opposite. They tell me to
use Edit mode. And, I see why.

I won't use anything else but Edit. Normal is good too, though I have
not done any actual comparison tests between Edit vs. Normal.

With Edit mode selected, your vcr *retains* the sources original and
full detail. But, in order for this to properly be accurate, or closely
accurate, one has to *record* in Edit mode to begin with, to see the
difference, and make assessments thereof.

It is my opinion that Commerical tapes are in line with Edit mode
already, on account of the finer detail from those types of sources.

I've recorded in other modes, and I can see pretty bad detail, like
too much smoothing, or masky-looking people, because of the smoothing
and/or combo of smoothing/sharpening that these vcrs feature as choices.

If you want to make the most from your vcr, you would be wise to record
*all* your sources in Edit mode, to gain the great detail to begin with.
That means, turn off your DNR and other filters your given vcr offers
you.

Later, if you are those who can't see past DNR or other filters that your
given vcr offers you, you can always turn them on later.

I realize that there are various other factors that reflect quality,
like vhs tape brand and quality-level. But, I have not really put this
area to test yet. I saw another topic on this forum talking about this
here (see below link) and I would like to see some examples of what was
talked about, "grain", etc.

--> whats a good decent vhs or svhs tape to use with my hr-3911u

I would like to see some example pics of various tape brands, please
I would also like to see some ET recordings as well.

Thanks.

-vhelp 3638

[kenmasters83]

vhelp...you are correct with your assumption with the *EDIT* feature on the jvc svhs vcr's..

i recorded several clips with a fresh svhs tape from fuji and well the results are well deadon with what your saying..

i too can see the bluryiness you speak of its very noticable when recording with the *SOFT* feature set to on..

when *EDIT* is enabled it does truly capture the signal as it was meant to be seen..

another thing i should mention is that the only time i use *SOFT* is when i record with supervhs-et enabled..i find that it reduces the noise a litte bit on cheap tapes like the jvc sx tapes..or when playing 10 year old tapes.

i personally cant tell a difference yet what the *SHARP* feature does during a recording as its minimal at best..

but i do know i will leave it in *EDIT* aswell..as it truly does produce the best possible picture quality.

[BrainStorm69]

Is there nobody else with a different TBC willing to put a little work into this thread?

[mike1061]

Please do. I am intrested in a TBC, and have been watching this thread. I don't have anything to add, I just wanted to say thanks.
Mike

[FulciLives]

I've been wanting to purchase the AVT-8710 for a long time now but it looks like I won't have the money until after the holidays.

I would contribute if I could but I can't as of now since I don't own a TBC other than the one built-in on my stand alone DVD recorder but since it can't be deactivated ... no way to test really.

Anyways this is an excellent thread ... I wish more would participate though

- John "FulciLives" Coleman

[SatStorm]

I also use "edit" with my Philips VR 1500 Match Line VCR

Even the manual notifies that "edit is the best option when you dub any tape to a second VCR / DVR"

I prefer to adjust the sharpness with my ACE Enchancer

[peterhuh]

Hi,
on the very first test,
there seems to be some loss of vertical resolution with the Ice Age cap.
I can see jaggy edges on Sloth's lower lips.

Is there something wrong with my IE browser, or there is really loss of vertical resolution with TBC3000?

[vdbdubber]

I have a For-A FA 425 TBC that I use only when necessary, usually when transferring an old ¾ tape to a BetaCam, for restoration purposes. On occasion I will use it when going from a BetaCam to our hard drive to help with synch issues.

I always get two mirrored angled bars that travel across the screen. They are usually subtle but I still can’t help but think there is some way of getting rid of them. Is this a power issue? I have not read about anyone else with this problem, in which case I hope it is easily fixable by some obvious method that slips passed me.

I have attached an image to help illustrate the issue. It is not a screen shot, and the lines are thinned and darkened to exaggerate the problem.

thanks for any help.