Quantcast Correcting distortion from external TBC? - digitalFAQ Forum
  #1  
08-24-2019, 04:30 PM
TheVistaGroup TheVistaGroup is offline
Free Member
 
Join Date: May 2019
Posts: 4
Thanked 0 Times in 0 Posts
Hi folks, I'm collecting and capturing interesting/weird/instructional/religious/travel VHSs I find in thrift stores. Starting with nothing, this has been an exhilarating and rewarding experience.

Workflow:
  1. VHS tape to
  2. JVC HR-S5900U S-Video Out (video calibration ON, all other settings off) to
  3. DPS-235 TBC (with proc amp settings adjusted manually per tape) S-Video Out to
  4. ADVC-110 to
  5. Firewire to
  6. Thunderbolt to
  7. USB-C to
  8. iMac to
  9. Final Cut Pro X
Problem: My DPS-235 is distorting the top section of video, bending it to the left slightly (in most cases), or dramatically (in few cases). The benefits I receive from the TBC outweigh this little issue.

I have installed Windows 10, and am curious to know: how I can correct this distortion without ditching the TBC altogether? Examples attached.


Attached Images
File Type: jpg setup pic.jpg (88.7 KB, 5 downloads)
File Type: jpg vlcsnap-2019-08-24-14h25m44s512.jpg (46.9 KB, 4 downloads)
File Type: jpg vlcsnap-2019-08-24-14h25m17s892.jpg (49.0 KB, 4 downloads)
Reply With Quote
Someday, 12:01 PM
admin's Avatar
Ads / Sponsors
 
Join Date: ∞
Posts: 42
Thanks: ∞
Thanked 42 Times in 42 Posts
  #2  
08-24-2019, 06:18 PM
lordsmurf's Avatar
lordsmurf lordsmurf is offline
Site Staff | Video
 
Join Date: Dec 2002
Posts: 8,516
Thanked 1,397 Times in 1,227 Posts
There's a reason the DPS/Leitch units are not suggested. Several, actually. It really does not do much, and is weak compared to TBCs designed for VHS. That was a broadcast rackmount unit with different sources in mind.

You've run into tearing. Sometimes TBCs cause it (bad reaction to tapes).
- Sometimes, maybe, the AG-1980 can fix it.
- But more often it requires the ES10/15 units.
- Of course, if the DPS causes it, nothing can be done but to use a suggested TBC.

Your VCR is low-end, no line TBC, so it complicates matters. Hard to place blame on anything yet. The tape is the root cause, timing errors, but either overcorrected or lack of correction is the issue here.

That's not a little issue.

If you ditch Mac, then also ditch the Canopus box, as it's losing 50%+ of your color quality (4:1:1) chroma compression. With Windows, there are better USB cards, some cheaper than the Canopis (yet better quality), and I have several available in the marketplace.

- Did my advice help you? Then become a Premium Member and support this site.
- Find television shows, cartoons, DVDs and Blu-ray releases at the TVPast forums.
Reply With Quote
  #3  
08-24-2019, 07:44 PM
TheVistaGroup TheVistaGroup is offline
Free Member
 
Join Date: May 2019
Posts: 4
Thanked 0 Times in 0 Posts
Thanks for the reply. There's no difference in color or "cleanliness" when using or not using the TBC, so I'll only use it when capturing a tape is difficult —*instead of using it all the time.

I also have a StarTech video upscaler (S-Video to HDMI) and a virtual machine of Windows 10, so perhaps I'll experiment with that and see if I can tell the difference between 4:2:2 and 4:1:1.

Thanks again!
Reply With Quote
  #4  
08-24-2019, 09:03 PM
lordsmurf's Avatar
lordsmurf lordsmurf is offline
Site Staff | Video
 
Join Date: Dec 2002
Posts: 8,516
Thanked 1,397 Times in 1,227 Posts
- TBC is always needed to avoid frame timing issues, often resulting in lost frames (thus losing audio sync)
- Upscaling is not suggested, messes with interlacing, loses quality
- You cannot capture in a VM, native OS required. (tip: dual boot)
- 4:1:1 will always lose noticeable color fidelity; note that it may be missed in the small capture window, but is very obvious viewed on most modern HDTVs

- Did my advice help you? Then become a Premium Member and support this site.
- Find television shows, cartoons, DVDs and Blu-ray releases at the TVPast forums.
Reply With Quote
  #5  
08-24-2019, 09:34 PM
TheVistaGroup TheVistaGroup is offline
Free Member
 
Join Date: May 2019
Posts: 4
Thanked 0 Times in 0 Posts
Aha, I see. So, when a capture is “terminated” automatically, is that usually a result of a dropped frame? That’s happened to me a bit.
Reply With Quote
  #6  
08-24-2019, 09:51 PM
lordsmurf's Avatar
lordsmurf lordsmurf is offline
Site Staff | Video
 
Join Date: Dec 2002
Posts: 8,516
Thanked 1,397 Times in 1,227 Posts
Outright termination of a capture is a common issue, especially with the capture Mac-based DV FCP(NLE) workflow you're trying to use. That whole workflow has capturing issues. Even with a stable signal, FCP would fight you.

Capturing can be easy, or a can of worms. You have the latter.

Video capturing can easily turn into the most miserable and hellish computer experience you've ever had, if done wrong, with the wrong equipment. Forget all the marketing puffery nonsense that was spouted by hardware/software manufacturers. Once you learn the technical aspects of video, you'll quickly see how those promises were ludicrous and clueless nonsense.

This is a basic working workflow:
- recommended JVC/Panasonic S-VHS VCR with internal line TBC
- recommended external framesync TBC -- or TBC(ish) to cut some corners on costs (but also some slight quality loss)
- recommended capture card, preferably using WinXP or Win7

Deviating from that increases problems. People try to fight this formula all the time, in an effort to not buy the proper tools. The usual excuse is that other equipment is "good enough", but that's just a euphemism for lousy quality.

Your root problem is the tape, probably correctable with a better VCR, but almost definitely correctable by a TBC(ish). With just a TBC(ish), you could then ditch the DPS, and the rest of the workflow would work. Better would be to replace the capture card as well, and capture on Windows (even 10 works, but again XP/7 gives better experience). I still have a TBC(ish) pair available, if you want it, in the marketplace, PM me.

- Did my advice help you? Then become a Premium Member and support this site.
- Find television shows, cartoons, DVDs and Blu-ray releases at the TVPast forums.
Reply With Quote
  #7  
08-24-2019, 10:30 PM
TheVistaGroup TheVistaGroup is offline
Free Member
 
Join Date: May 2019
Posts: 4
Thanked 0 Times in 0 Posts
Man I appreciate your thorough responses. You're doing more for the VHS community than the capturers/restorers themselves just about!

What's the point of capturing VHS in your opinion- restoring the video to be attractive and appropriate for today's audience, or archiving the format as it exists in <current year>?
Reply With Quote
  #8  
08-24-2019, 11:06 PM
lordsmurf's Avatar
lordsmurf lordsmurf is offline
Site Staff | Video
 
Join Date: Dec 2002
Posts: 8,516
Thanked 1,397 Times in 1,227 Posts
Thanks.

The main point is to archive it in the best possible quality. Nobody likes to watch crappy quality video, and in fact most people simply won't watch garbage. No complaints, no trying to find/do better, just move on to something else. It's not enjoyable, too distracting.

And the reason for archiving is because lots of content is unique, unreleased in a digital form (or at least unreleased in uncut/uncensored form), though some do it simply because of nostalgia (or a "time capsule of recordings", as a person on this site put it a few years ago).

It's hard to make VHS "attractive and appealing" in the HD era, but you can certainly not make it look worse than the tape. Cheap/sloppy/wrong methods or worse. Good tried-and-true methods extract the full tape quality, correcting analog errors on ingest. Sure, you can further tweak color at a scene-by-scene/micro level, and many do, but that's never been my focus. That really NLE work, color grading, post-capture, post-restoration.

- Did my advice help you? Then become a Premium Member and support this site.
- Find television shows, cartoons, DVDs and Blu-ray releases at the TVPast forums.
Reply With Quote
Reply




Similar Threads
Thread Thread Starter Forum Replies Last Post
Correcting Washed Out Captures? ehbowen Capture, Record, Transfer 3 08-06-2018 07:05 AM
Color Correcting and Removing Artifacts from 8mm Film Scan ehbowen Restore, Filter, Improve Quality 17 06-05-2018 03:49 AM
Can a TBC fix this distortion? zoltanx Restore, Filter, Improve Quality 1 09-19-2016 04:41 AM
Help correcting de-interlacing problems, please. TerryJW Restore, Filter, Improve Quality 1 06-21-2016 04:25 PM

Thread Tools



 
All times are GMT -5. The time now is 09:35 AM