Genlocking VHS to Betacam?

[lordsmurf]

By using an HDMI adapter, you're massively screwing up the signal. You won't be able to tell anything whatsoever.

People need to quit trying to force SD content into HD/HDMI. It's not a simple matter of adapting, but one of reprocessing the signals. Whatever flaws exist in the SD signal are now baked in, forever embedded in the video. That's not good.

The rolling indicates it's not a TBC, at least not for the source being used. That's not unexpected behavior.

Solution = get an actual frame TBC.

[latreche34]

Quote:

Originally Posted by Shakedown St.

However the Betacam manual says it has digital dropout compensation. I'm not exactly sure what that implies.

A digital circuit that compensates for missing RF signal due to tape drop outs, For the age of that VCR I'm guessing it will be a line or two compensation, Not like something fency from JVC VCR's at the end of the VHS era that used not just multiple previous lines but fields to correct for noisy lines.

LTBC, DNR and DOC usually work all together to avoid multiple A-D and D-A conversions.

Here is a how it looks

[Shakedown St.]

Quote:

Originally Posted by lordsmurf

By using an HDMI adapter, you're massively screwing up the signal. You won't be able to tell anything whatsoever.

People need to quit trying to force SD content into HD/HDMI. It's not a simple matter of adapting, but one of reprocessing the signals. Whatever flaws exist in the SD signal are now baked in, forever embedded in the video. That's not good.

The rolling indicates it's not a TBC, at least not for the source being used. That's not unexpected behavior.

Solution = get an actual frame TBC.

Now I think we're getting somewhere. So we've determined that unlike the Panasonic AG8700 which does have full-frame pass-through capabilities the Betacam decks do not. That is what I originally set out to determine to crush the rumors. It is still yet to be determined whether Betacam can act like the Panasonic "ES" series recorders as line TBC pass-through (not real line TBC). My hopes on the usefulness of the experiment are now starting to dwindle.

When all is said and done if TBC does not work, it could be that Betacams are no more useful than buying a Sima SCC for proc amp controls (wish I could find one of those for sale) only 50X bulkier and heavier. Don’t want to call it a failed experiment yet though.

Quote:

Originally Posted by latreche34

A digital circuit that compensates for missing RF signal due to tape drop outs. For the age of that VCR I'm guessing it will be a line or two compensation, Not like something fancy from JVC VCR's at the end of the VHS era that used not just multiple previous lines but fields to correct for noisy lines.

Now I was reading this from your host, but I assume those JVCs come from a much later era.

“A trivia worth mentioning is that the Panasonic AG-1980P comes with a "full field" TBC, which is not the same as a full-frame TBC. It's more like multiple lines of correction, instead of single-line correction. However, it is not superior (simply due to having extra lines) to the single-line TBCs found in the higher-end JVC S-VHS VCRs.”

By the way great thread with loads of information below.

http://www.digitalfaq.com/forum/vide...#ixzz6yJpOSt00

-- merged --

Update. I'm about to purchase a TBC calibration tape on eBay for $100 so I can conduct this test. It has lines and shows test screens to make comparisons back and fourth. If this is a bad idea please and thank you stop me. When this is all over I'm probably purchasing an external frame TBC before I run the device into Betacam. A lot of external TBCs have proc controls which makes the Betacam now kind of a redundant and pointless and uneeeded step unless it offers line fixes. Hmmmm...

Last night just shooting the the wind I tried running s-video into the Sony SVO-5800, ran digital component out to Betacam, then digital component out of the Betacam to my television set to see if it stabilized and liked a digital signal better. I'm sure there is a technical reason why but I got a blank no signal at all. So step #2 has been debunked.

At this point now to have any meaningful test I have to use the AG7350 with external sync, which means I have to replace four fried caps on the the servo circuit because it won't track at all. Think I may be better off buying the TBC first and using a different VCR to run the test.

Quote:

Originally Posted by Alessandro Machi

The Panasonic 1980 was probably one of the most utilitarian VCR's ever made. In the six hour mode picture quality wise nothing was better than the Panasonic 7350.

I can't help but look back at this comment a month later. It should be noted that the 7350 now that I've had some time with it does not have frame or even line TBC capabilities that most newer JVC and Panasonics had by the mid 90's. The AG1980 does line corrections very well. This is something that really cannot be acomplished externally unless the Betacam turns into a miracle. I'm still not giving up on this project until I have a definite answer.

I believe you mentioned that because the six hour head does not read HiFi that it produces superior image quality. That would make some sense. HiFi has been known to interefere with picture during loud parts. Notabably in movies with lots of explosions.

[lordsmurf]

Quote:

Originally Posted by Shakedown St.

Update. I'm about to purchase a TBC calibration tape on eBay for $100
If this is a bad idea please and thank you stop me.

That's nuts. Don't do that.

Quote:

When this is all over I'm probably purchasing an external frame TBC

Just do this.
And don't make the mistake of buying any random "TBC" (rackmounts, flawed chipset Cypress, bad TBC-1000s, etc). Don't be a goober, run to eBay with your dollars. You're more likely to waste more money there, that's almost never where you find good TBCs. And you must realize that most sellers are liars and idiots, or both, and know zero about the items they're selling.

Quote:

A lot of external TBCs have proc controls

Yes and no.
- Some TBCs have weak proc amps. Good for minor corrections. AVT-8710, etc.
- Few TBCs have stronger proc amps. TBC-3000.
- Some TBC "proc amp" are actually just calibrations for the TBC itself, not really true proc amps.

Also don't be a goober and run to eBay/etc now looking for AVT-8710 or TBC-3000. Again, you don't want a random unit. The black AVT-8710 is bad (as are any "black era" Cypress, like 1T-TBC), and the rarer TBC-3000 3rd gen is the only TBC-3000 worth getting at today's TBC prices.

[latreche34]

You don't need $100 tape to test line timing signal, As I said before any tape with vertical white lines even you can record a video yourself into VHS that has that type of contents say a test card from a still digital file, Put that money into good use don't throw it away.

[durian]

Hi everyone! just joined the forum so i am a bit late to this thread. My setup has a pvw-2800 beta sp deck. to stop the rolling you need to provide a reference signal . i was told to get this deck to do tbc between my jvc9600u and capture card instead of a dvd player. the guy giving me advice runs a "videotape retro" youtube channel and has some of the cleanest transfers i have seen .he told me to take the composite output from vhs and run to the ref in connection on betacam deck. the same day he told me that i stumbled across a sony tips section for the deck that a gave the same advice. if you do not have a composite out you can split an svideo signal and convert one of the outputs to rca. under the flip panel on the beta deck the setup control seems to be the black levels (another poster said contrast ). video is brightness .i capture in with a BMD 4k extreme 12g card .so far working well for me,even on horrible material very little dropped frames none that stopped recordings no audio sync issues . i needed a decklink for color grading so this seemed like a good way to go. as long as i have the original source tapes i have been impressed by the jvcs ability to sort things out

[RobustReviews]

Quote:

Originally Posted by durian

Hi everyone! just joined the forum so i am a bit late to this thread. My setup has a pvw-2800 beta sp deck. to stop the rolling you need to provide a reference signal . i was told to get this deck to do tbc between my jvc9600u and capture card instead of a dvd player. the guy giving me advice runs a "videotape retro" youtube channel and has some of the cleanest transfers i have seen .he told me to take the composite output from vhs and run to the ref in connection on betacam deck. the same day he told me that i stumbled across a sony tips section for the deck that a gave the same advice. if you do not have a composite out you can split an svideo signal and convert one of the outputs to rca. under the flip panel on the beta deck the setup control seems to be the black levels (another poster said contrast ). video is brightness .i capture in with a BMD 4k extreme 12g card .so far working well for me,even on horrible material very little dropped frames none that stopped recordings no audio sync issues . i needed a decklink for color grading so this seemed like a good way to go. as long as i have the original source tapes i have been impressed by the jvcs ability to sort things out

Yes, this is a way getting a lock between various devices.

Some (?) Betacam decks I think can be set to just sync on the composite input but this would be a rather 'near enough' way of doing it in broadcast where everything would be sync'd seperately but it's a perfectly good method for VHS etc.

We have to employ this trick if we do domestic -> SDI through Sony units otherwise there's no sync' and everything is a rolling mess.

Some seriously high-end VHS machines do have genlock connections, but that's getting into the weeds.