Confused: Why a VCR with TBC if separate TBC needed anyway?

[BrainStorm69]

the S-VHS cap was WAY better and less noisy than the VHS caps.

This may be dependent upon the VCR.
I notice that your Toshiba VHS VCR pics of VHS playback are clean.
I also notice that your JVC SVHS VCR pics of VHS playback are noisier, similar to vhelp's VHS pics.

Perhaps the JVC SVHS VCRs do not perform as well with VHS tapes as the Toshiba VHS VCR?

That may be true. I do think the DNR of the Toshiba is pretty good (somewhat better than the JVCs'). I may have to repeat the test on the Toshiba without the DNR and see what they look like. I may even do the test with several of my other VCRs when I get the time.

[vhelp]

One question realted to the recording with the JVC on VHS tape. Does your JVC
support SVHS-ET recording? If so, are you sure that the VHS recording on the JVC wasn't
done in SVHS-ET mode? My experience with SVHS-ET is that it does give a bit better
resolution, but more noise than regular VHS recording. Those VHS tapes just were really
not made to handle the bandwidth, I think.

I'm not sure what you mean by this.

But, my JVC unit *does* support this feature. On the unit, there is a logo
with the S-VHS EP and a button associated with it, and when pressed in, it
lights up w/ a green dot and followed by turnning on a logo/blip S[VHS]

I'm just not sure which does which, and at what time, etc. So, I just assume
that it is off, all-together.

But also, I don't know if that is *strictly* for svhs tapes or vhs tapes, or
both.. (I can't find my user manual at the moment)


A special note on the purpose of this test "for finding timg-base -/+ sync - theory".

I don't see how this would be as important to know, other than to know
what is causing one's issues with regular vhs tapes (assumed to be non-comm,
and user produced by "aged" equipment, and cheap vhs tape brands of
those days) that they are trying to transfer via capture device.

I mean.., most of the times, when a user experiences issues with vhs
tapes, it is mainly on account of the capture device and circuitry or
driver who's soul design and purpose is to react/jam the signal with
the audo-assumption of *any* given source being assumed copy-righted.
Thus, causing the reactions you see, relating to Macrovision.

The time-base sync issues (or there phenominas seen) are usually aided by
this Macrovision, or the unit's hardware circuitry auto-kicks in, or the
software driver for the capture device kicks in, (all Macrovision related)
and causes all those random issues during tape capturing projects.

In my many experiences with vhs tapes, all these issues were derived from
Macrovision. Dropped frames was number one enemy on my list, during the
older days of my capturing. When you see "taring" or "curling" of the
tape play (during capturing) you would see random frame drops from this.

Then, there is the capture cards that *seem* to sware that they avoid any
Macrovision. The DC10Plus [DC10+] cards is a good example. This card
*seems* to ignore Macrovision, but alas, it screams loudly, and "curls"
the top portion of the video. This would cause random frame drops.

Sometimes, devices will *seem* to fight this beast, Macrovision. As with
the DC10+ card, it fought with it, and won, but with a price.. dropped
frames, and "curling" at the tops of the video. What I am saying here,
is that there are other such cards that share in this experience.

This (above) was just an example of what *could be* seen as time-base
sync issues.. or something else, time-base (TBC) wise.

Then, there are those cards (TBC's) that say they are this, but are that,
or do this, or do that

My TBC-100 card is such a card. Without going into details, it too, acts
weirdly. Though, it does "shift" the video picture left/right (I forget)
and also, it seems to "filter" or "loose minoote image detail" as an
flaw or whatever issue.

Ok, lets get back on track here

I should give my TBC-100 a shot at seeing if it would straighten out those
virtical lines. Forgeting for a moment, the issue I just mentioned about
this card, and just go for the test part. That would be interesting.
Does it live up to the BrainStorm69's test of Virtical limits.. I don't
know..

-vhelp 3784

[vhelp]

I think that most VCRs exhibit some time base errors on pre-recorded VHS tapes
also. In comparing captures of various pre-recorded VHS tapes played on my JVCs with the
TBC on vs. caps from other VCRs without TBCs, I have frequently noticed subtle time base
errors in the caps from VCRs without TBCs. They are not easy to see without comparing
exact frame screen caps unless there are vertical straight lines in a particular scene,
but they are there. I'm interested in that as well as tapes made on different vcrs because
I also have a significant number of pre-recorded VHS tapes to back-up.

Yes, I've briefly talked about this in my previous post.

When the source tape is a Commercial tape, it has Macrovision embeded.
And, when the capture card receives the images, it does whatever it was
disigned to do, and in the end, (depending on the card maker's design
purposes) will react, Macrovision'wise. I would suppose that it is up
to the Maker's of the device, who serves (I mean) incorpates the Macrovision
"reaction" method. This could be "taring of the video" or "Curling",
or "color reduction" or "brightening/darkening" the video, etc.

No matter what, any method of "reaction" for the purpose of serving
Macrovision, will surfice and cause the capture device to fail or
produce bad video. In any event, the user would not be able to make
much use of the captured source.

I also have a significant number of pre-recorded VHS tapes to back-up.

Pre-recorded tapes should not be a problem, unless they have aged to the
point of requiring a TBC or such device to help fix it. In addition,
the capture device should be considered, when working with aged tapes.

Having a non-Macrovision type capture device is criticle during these
times. And those that do not serve this devil will produce very clean
and stable video. And, the better the capture device, the better the
video results.

My belief is that if the capture device is from an ATI brand, it will
probably suffer some form of "false" Macrovision, and consiquentially,
result in those mentioned issues above. (based on actual experiences,
we'll exclude ATI cards of the BTxxx chips, as they don't exhibit any
Macrovision nor false ones for that matter -- the ATI TV Wonder VE is
just one example BTxxx chip, which I have and own)

(FWIW, ATI is one of the greatest servant of Macrovision)


Determining weather or not you have Time-Base issues ...

Below are just a few brief notes on this.

I suppose a good way of determining or verifying your given setup
for flawless operation, is to use an capture device that absolutely
does not serve Macrovision.

I know with absolute certainty, two capture devices that do not serve
Macrovsion. The ADVC-100 and the ATI TV Wonder VE. These two
would be a good tool for preliminary testing of time-base issues.

Thus, if you capture with these, any vhs materials, and you have no
problems or issues, then you are just about ready for the next steps.

But, if you do see problems, then you have to look at your vhs tape
and equipment, or use a device that fixes the video. Course, it would
help if you knew/know what to look for first, then solve with the proper
tools.

But just throwing in a TBC or tool at every vhs tape is not a wise and
practicle excerise. The number one important rule/step here, is first
start with a capture device that does not serve Macrovision.

This process will determine your next steps.

-vhelp 3785

[BrainStorm69]

@vhelp -

SVHS-ET is using VHS tape to record S-VHS bandwidth, at least theoretically. If you didn't have the SVHS-ET button "on," then your recorder just recorded VHS.

As far as MV goes, my AverMEdia DVD EZMaker card completely ignores it. I've never had a problem at all capturing anything commercial and MV protected with the card (thank god) . So I do not believe the time base errors I am talking about related to commercial VHS tapes are MV related. They are caused the same way the time base errors that show up in the tests of non-MV protected video we just did are caused. Differences in the mechanical aspects of the different machines that record and play the tapes. These errors show up as small displacements in the picture just like in the test examples we posted above, they are just subtle and somewhat difficult to notice unless there are straight vertical lines or edges to objects in the picture. I'll see if I can post some images later to show you what I mean.

As far as using your TBC-100 to see if it fixes the problems, I expect that it won't, at least not to any significant degree, since my TBC-3000 doesn't. But it would be worthwhile to confirm it.

[vhelp]

As far as using your TBC-100 to see if it fixes the problems, I expect that it
won't, at least not to any significant degree, since my TBC-3000 doesn't. But it would
be worthwhile to confirm it.

Ok. I will see what I can do to help confirm this with you.

(I just wish my TBC-100 was easy to rig up with a power supply. I hate
having to hook it up to my pc for tests and things - it's annoying.
And I just blue another UPS power supply/fan on my pc here, though lucky
for me, I had another one, and brand smelling new)

- hay.. another idea came to me ...

Anyways.

I'm going OT here..

I need to pick up a couple of vhs head cleaner kits. Any brand you might
have for suggestions via K-Mart ??


-vhelp 3788

[vhelp]

Another addition, [Tue, Jan 24, 2006] ...

I revised [page 2] to include another test image performed by myself,
and my equipment, and using BrainStorm69's "test pattern" vob.

( The reason for revising from page 2 with this info, is because that was
the page where my test excerise originated from )


REFERENCES:
** 1st test pattern vob here - if it hasn't been removed yet, or
** fully assembled test vob here - last latest one U/L'ed
** Instructions to produce DVD test disk here - requires ifoEdit and TMPGenc [MPEG Tools]
** [Page 2] - has more info on all the tests I ran so far.


-- Note, from previous processed tape, mentioned again for posterity sake --

Again, I used my Sony SLV-685HF vcr for this latest test's (continued)
and analysis. Thus, I hooked up my AD-1500 dvd player to the Sony vcr, and
RCA wire, and recorded to the Sony in SP mode onto a regular vhs tape.
-- ***************** --

In this latest test, I proceeded to play the latest recorded regular vhs tape
inside the Sony SLV-685HF unit, and SP mode.

And, I captured from this vcr (above) to my ADVC-100 (dv device) using the
RCA wire connectors, and used same method with vdub, noted in a previous post
to obtain .BMP pic, finalized to .PNG file as other pics.

In block diagram form:

AD-1500[out: RCA] -> sony.vcr[in: RCA, r-VHS, SP][out: RCA] -> ADVC-100[in: RCA]


To view all the pics in their entiretiy, head over to [Page 2] here.
You can find more info on all the tests I ran so far.

Here is an example of my lastest pic test excerise:



** test.pattern.ad1500.sony.rca_sony.rca.advc.sp.1.pn g -- added Tue, Jan 24, 2006
-- AD-1500 -to- sony.vcr[r-VHS, SP], (sony[r-VHS, SP] -to- advc -- all RCA wire --


Some notes..

I found it interesting to note how the image's virticle looked so
straight and no sign of kinks in them. I guess that the best all
around method is to *stick* with your vcr throughout. That is,
if you record to vcr A, then, you should capture from this same
vcr A. Otherwise, just as BrainStorm69 has theorized (if I may
interject here) that problems (time-based related, for instance)
will arise.


@ BrainStorm69

I think I am begining to understand where you are headed with all this.
And, my eyes () are opening even wider than before

( fwiw, I haven't run that test excerise w/ the TBC-100 yet. I wanted to
finish up on this (above) idea I mentioned )

So far, good post

From the Video Workstation of,

-vhelp 3791

[BrainStorm69]

Some notes..

I found it interesting to note how the image's virticle looked so
straight and no sign of kinks in them. I guess that the best all
around method is to *stick* with your vcr throughout. That is,
if you record to vcr A, then, you should capture from this same
vcr A. Otherwise, just as BrainStorm69 has theorized (if I may
interject here) that problems (time-based related, for instance)
will arise.


@ BrainStorm69

I think I am begining to understand where you are headed with all this.
And, my eyes () are opening even wider than before

@vhelp - I think it now seems to be pretty much a given (although I'm still open to evidence otherwise) that using different recording and playback vcrs will cause time base errors. But where I'd really also like to go with this is to determine if you will always have time base errors capturing pre-recorded VHS tapes without the use of a TBC because by definition, the recording device is different than the playback device. And what I'd really like to determine is whether there is a stand-alone TBC that you can use with VCRs that don't have internal TBCs that comes close to what the JVC VCRs with internal TBCs can do with respect to correcting these time base errors. Unfortunately, I have only one response to my thread on that topic, and no pictorial evidence.

@ Davideck - I'm sure you will read this sometime. I think it would be interesting to try this test on the older JVC VCRs to see if their better transport system minimizes the problem.

[vhelp]

fwiw mentioning here...

I did a little reading up on my JVC manual (I found it) and it has the
feature to "manually" adjust tracking. Now, assuming that it has some
relations to time-base attributes, I was wondering if that would help
with the time-base issues in the images posted so far, and if so, would
runing additional test be necessary - to be sure.

Also, for afficial purposes, in getting the proper terminology of such
issues into perspective..

In the pics I have posted, (those that gave you the insight to time-base
errors) with the "kinks" in some parts of the virticle lines, the question
I have is:

"Is or should this be refered to as, 'time-base' or else some other error" ??

Thanks,
-vhelp 3793

[davideck]

Also, I'm hopeful we can get some other folks to use this test with VCRs without built-in TBCs, but with commercial grade external TBCs to see if the commercial grade TBCs can remove or lessen the waviness caused by time base errors that the Datavideo TBCs don't.

Here you go.
I borrowed the FOR.A from work last night just for this experiment.
Eight Captures. Unstable VHS Recording. Playback on JVC HR-S7600.

1 ) 7600(TBC Off) -> PVR-250
2 ) 7600(TBC Off) -> LiteOn 5104 -> PVR-250
3 ) 7600(TBC Off) -> DataVideo -> PVR-250
4 ) 7600(TBC Off) -> FOR.A-> PVR-250

5 ) 7600(TBC Off) -> MiniDV Dub -> PVR-250

6 ) 7600(TBC On) -> PVR-250
7 ) 7600(TBC On) -> DataVideo -> PVR-250
8 ) 7600(TBC On) -> FOR.A-> PVR-250

I think it would be interesting to try this test on the older JVC VCRs to see if their better transport system minimizes the problem.

With respect to older VCRs and better transports...
VCRs introduce timebase errors during record and during playback, so its an interactive process.

Recording and Playing on the same VCR seems to minimize the overall timebase error. The Record error profile is matched and cancelled by the Playback error profile. Vhelp's pics point this out.

For different Record and Playback VCRs, the process seems roughly additive. Stable VCRs will not compensate for recordings made on unstable VCRs. But stable VCRs will minimize the additional timebase errors added during playback.



JVC 7600 with TBC Off


JVC 7600 with TBC Off with LiteOn 5104 DVD Recorder


JVC 7600 with TBC Off with DataVideo TBC-3000


JVC 7600 with TBC Off with FOR.A FA300


JVC 7600 with TBC Off -> MiniDV Dub


JVC 7600 with TBC On


JVC 7600 with TBC On with DataVideo TBC-3000


JVC 7600 with TBC On with FOR.A FA300

[davideck]

"Is or should this be refered to as, 'time-base' or else some other error" ??

Yes, the kinks should be referred to as timebase errors.

[BrainStorm69]

@davideck - thank you for your testing efforts! While the FOR.A looks to me like it does a better job than the Datavideo, it still doesn't come that close to the JVC's internal TBC. What model FOR.A TBC is it? I'd l;ike to find the specs and see if they are comparable to the other TBCs you and I found specs on that are +/- 15ns for residual time base errrors.

Any theories on why the JVC still does a better job?

EDIT: FYI, I should be getting the AG-1980 today. May be able to run a few quick tests on it tonight.

[davideck]

@davideck - thank you for your testing efforts! While the FOR.A looks to me like it does a better job than the Datavideo, it still doesn't come that close to the JVC's internal TBC.

I agree, although the error at the very top is quite substantial so its a pretty extreme test. Even the JVC TBC doesn't completely eliminate it, but it does show how much better the JVC is.

Creating the unstable recording was the fun part. I ended up sticking tiny pieces of foam tape on top of the scanner in one of my VCRs.

I was attempting to generate timebase errors by creating a weight imbalance on the rotating upper drum. Instead, the edges of the foam tape started slapping against the top of the VHS tape as the scanner rotated! The whole thing was buzzing like a swarm of bees! When you were a kid, did you ever use clothespins and playing cards to make your bike sound like a motorcycle? It sounded kind of like that. At first I didn't know what to do...but then I thought "well, this should create some nasty timebase errors" and so I let it run for a minute or so.

In any event, nothing caught on fire, the VCR has recovered, and I am pleased with the result.

What model FOR.A TBC is it? I'd l;ike to find the specs and see if they are comparable to the other TBCs you and I found specs on that are +/- 15ns for residual time base errrors.

The FOR.A model is the FA-300. It is also spec'd at +/- 15 ns residual error.

Any theories on why the JVC still does a better job?

I wish I knew. I have the schematic of the 9800. The TBC/DNR system contains one ASIC and one memory chip. These same devices also function as the comb filter during record. Very impressive.

And to think that the Panasonic may be even better...good luck with your tests!

[vhelp]

Evening everyone

Hi guys,

Could be nothing, but..

I got an idea. It's rather crazy, and never been done before, least not
in this type of situation in what we are trying to determine with respect
to time-base issues.., or anything, for that matter. And this could be
used as a new way of tooling around for answers.

If you can wait, while I try and set the stage for things to come. I have
to first see if it is do'able, and perform a few quick test runs. And if
everything works out the way I have imagined it to..

Stay tuned

-vhelp 3794

[BrainStorm69]

@vhelp - international man of mystery, eh? I'm interested to see what you've got.

Otherwise, I have the Panny. It seems to be in pretty good shape, although not pristine by any means. I suspect that it could stand a good head cleaning, and to be in really good operational shape, I bet it could stand to have all the rubber and belts replaced and to be lubed. It squeaks some when fast forwarding and groans a little when you hit rewind or fast forward.

There is a 3-way switch for "detail," "normal" and "edit," as well as a slider bar for picture sharpness, going from "soft" to "sharp." One thing I have noticed in my testing so far is that it doesn't seem to suffer from the time base errors as much as my other vcrs when the TBC is off. And for this particular test, the best picture seems to be provided with the 3-way switch set on "detail" and the slider bar all the way to "sharp." There is also something strange that I can't yet account for. The tga file for the screen cap without the TBC on is about half the size screen cap with it on. I'm just not sure what's going on in that regard.

Anyway, I'll leave you with a few screen caps to take a look at to see what you think. Note that only the last one is with the TBC on.


AG1980-edit-sharp-TBCoff


AG1980-norm-sharp-TBCoff


AG1980-detail-sharp-TBCoff


AG1980-detail-sharp-TBCon

I need to do more testing as I have time. I also need to do what I can to service it myself - mainly cleaning the heads and tape path.

[FulciLives]

The AG1980 looks damn impressive but one thing I need clarity here on ... was the tape used recorded with the AG1980 or recorded with another VCR then played back on the AG1980.

Have we determined that recording the test pattern on the VCR that you play it back on resutls in better results than recording it on VCR A and playing it back on VCR B?

- John "FulciLives" Coleman

[BrainStorm69]

The AG1980 looks damn impressive but one thing I need clarity here on ... was the tape used recorded with the AG1980 or recorded with another VCR then played back on the AG1980.

Have we determined that recording the test pattern on the VCR that you play it back on resutls in better results than recording it on VCR A and playing it back on VCR B?

- John "FulciLives" Coleman

The tape used was the exact same one used for the JVC tests - recorded on my HS-U781 Mitsubishi machine. And yes, generally speaking, I think we have determined that playing back in the machine on which the recording was made is generally better as far as minimizing time base errors go.

Edit: I agree that the Panny with the "detail" setting looks pretty darn good on this test. The "detail" setting somehow cleans up the aliasing that appears on the "edit" and "normal" settings. Unfortunately, the manual is weak in explaining these settings. All it says is that switch is "for controlling the picture image."

[FulciLives]

I agree that the Panny with the "detail" setting looks pretty darn good on this test. The "detail" setting somehow cleans up the aliasing that appears on the "edit" and "normal" settings. Unfortunately, the manual is weak in explaining these settings. All it says is that switch is "for controlling the picture image."

I agree that the last two pics (using the detail-sharp setting) look best. The one with the TBC on I think looks the best but even without the TBC the "wavyness" or TBC error(s) are just barely there ... rather amazing if you ask me.

I guess the next step is to see if the AG1980 works that well in "the real world" ... I'm suggesting some captures using not test signals but quality SP VHS recordings ... maybe even commercial pre-records. Perhaps even compare it this way to your other VCR units or at least the Toshiba and JVC units.

- John "FulciLives" Coleman

[BrainStorm69]

I agree that the last two pics (using the detail-sharp setting) look best. The one with the TBC on I think looks the best but even without the TBC the "wavyness" or TBC error(s) are just barely there ... rather amazing if you ask me.

I guess the next step is to see if the AG1980 works that well in "the real world" ... I'm suggesting some captures using not test signals but quality SP VHS recordings ... maybe even commercial pre-records. Perhaps even compare it this way to your other VCR units or at least the Toshiba and JVC units.

- John "FulciLives" Coleman

I agree that more testing is needed, including "real world" stuff. I'm also interested in seeing if the AG1980 does that well minimizing time base errors without the TBC "on" from tapes made on some of my other VCRs, or if it is just a fluke that it did this well with the recording made on my Mitsu.

[davideck]

OH MY GOSH!!!

Sorry for all the capitals, but look what happens when I record my unstable VHS tape to MiniDV (without any TBC) and then play it back. The timebase errors were clearly visible in the Camcorder view finder during record. Where did they go during playback?

For a comparison, go back to my previous post of images in this thread. I have also posted this image there.


JVC 7600 with TBC Off -> MiniDV Dub

[Wile_E]

************************************************** ***********************************
1/28/06 UPDATE:
I have replaced all caps. Used VirtualDubMod to obtain caps, and have added the Sharp Mode caps.
************************************************** ***********************************

Here are comparisons from JVC 9911U. Recorded to Sony VHS "Premium" tape. ADVC300 had everything turned off except for AUTO AGC. JVC had Digital R3 off.

Record Workflow...
VOB on Vegas timeline > DV out to ADVC300 > JVC 9911U S-Video

Played back workflow...
JVC 9911U S-Video > ADVC300 > Vegas timeline > JPG screenshot

DNR TBC OFF AUTO MODE R3 OFF


DNR TBC ON AUTO MODE R3 OFF


DNR TBC OFF EDIT MODE R3 OFF


DNR TBC ON EDIT MODE R3 OFF


DNR TBC OFF SHARP MODE R3 OFF


DNR TBC ON SHARP MODE R3 OFF

[FulciLives]

OH MY GOSH!!!

Sorry for all the capitals, but look what happens when I record my unstable VHS tape to MiniDV (without any TBC) and then play it back. The timebase errors were clearly visible in the Camcorder view finder during record. Where did they go during playback?

For a comparison, go back to my previous post of images in this thread. I have also posted this image there.


JVC 7600 with TBC Off -> MiniDV Dub

What MiniDV did you use? A camcorder with analog-to-digital pass-thru and if so what model etc.?

My guess is that the MiniDV cam (or whatever it was) has a TBC built-in.

That pic does look rather amazing !!!

- John "FulciLives" Coleman

[davideck]

What MiniDV did you use?

JVC GR-DVL915U

The best TBC I have has been hiding in my Camera Bag!

[Wile_E]

My gosh, my caps look blurry compared to the previous AG-1980. What did I do wrong? I will try again tomorrow. It is getting late. The JVC 7600 even looks a lot better. Anyone else have a 9911 that they could try this test on?

[FulciLives]

My gosh, my caps look blurry compared to the previous AG-1980. What did I do wrong? I will try again tomorrow. It is getting late. The JVC 7600 even looks a lot better. Anyone else have a 9911 that they could try this test on?

Maybe try a different method of doing the screen shots like using VirtualDubMod for instance (that's how I do all my video capture pics).

- John "FulciLives" Coleman

[davideck]

A camcorder with analog-to-digital pass-thru

I didn't try the pass-thru. Maybe I don't have to dub to tape.
I'll try that tomorrow.

[lordsmurf]

On my new LCD monitor, those images davideck posted above truly look like shit. All of them. They suffer from some sort of image processing flaw, when they were turned into JPEGs.

All the other images on the page are fine.

So don't think too hard into it Wile_E. Your image do appear slightly softwer than BrainStorm69's, but not a whole lot.

Consequently davideck, sorry. I'm not really reading this post anymore. Not sure what your images are for here, but they look awful. If I were you, I'd redo them all.

[davideck]

Consequently davideck, sorry. I'm not really reading this post anymore. Not sure what your images are for here, but they look awful. If I were you, I'd redo them all.

Sorry about that.
It was easiest for me to count and capture frames using VideoReDo. The version I am using only lets me capture up to 640x480.

They look fine on my CRT...

[The_Doman]

What MiniDV did you use? A camcorder with analog-to-digital pass-thru and if so what model etc.?

My guess is that the MiniDV cam (or whatever it was) has a TBC built-in.

That pic does look rather amazing !!!

I have the same good experience with my Sony D8-DCRTRV120 analog in/passthrough option.
Unstable VHS stufff comes out perfectly stabilized, it really works great...

Maybe try a different method of doing the screen shots like using VirtualDubMod for instance (that's how I do all my video capture pics).

Yes this an very important factor, different capture programs can give different results.
Also the used (DV) codec can make a very big difference!
For example the popular mainconcept DV codec will give a extremely sharp image compared to other DV codecs. This is not always what you want with a (noisy) VHS source..

[BrainStorm69]

@davideck - those caps don't look bad on my monitor other than the "reswedge 720-480" looks pretty aliased, which may be because your screen cap is 640x480. Otherwise, they look quite good. Can you use vdub or vdubmod so you can get a 720x480 screen cap? It will be quite interesting if the passthrough on your camcorder works this way!

@Wile_E - I don't think your caps look all that different than the ones I posted earlier in the thread from my JVCs. However, I think it would help if you could use vdub or vdubmod to capture your images also. I think there have been other threads were it's been shown that some programs make screen caps better than others. It would be helpful for comparison purposes if we were all using the same program for screen caps. Also, did you try using the "sharp" mode on your 9911? I'd like to see some caps from you using "sharp" mode also.

[davideck]

BrainStorm69 -

I'll see what I can do this weekend. As I'm sure you can imagine, I'm a bit preoccupied with wanting to test the pass-thru performance. I also want to haul out an oscilloscope to see if my MiniDV camcorder provides continuous sync at its Analog output. Maybe it's a great synchronizer too!

I checked out my images on an LCD Monitor and some did look a bit washed out. I realized that 640x480 was not the optimal choice when I posted them. But as this was a thread about timebase errors, I was not focused on comparisons of brightness, sharpness, etc.

Wile_E, my images may not provide valid comparisons for the concerns that you have mentioned.

But I believe that the timebase error profiles are accurately represented in my images. My intention was to provide a relative performance display of timebase correction capability. So I created one unstable VHS source tape, played it back on one VCR, and captured with one device for all of my tests. The only difference was the TBC device. In all of my images, the timebase error magnitude is most significant at the very top and then decreases down the frame. You can therefore compare the performance of each TBC device by identifying where the wavy lines become straight as you look up and down along the Vertical axis.