Digital8 camcorder converts Hi8 tape to DV25 before outputing S-Video analog
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- Опубліковано 15 січ 2025
- If you have Video8 or Hi8 tapes, you can play these back with a Hi8 camcorder or a Digital8 camcorder. They can both play the tapes. But our updated conclusion is that you should play back these tapes with a Hi8 camcorder instead of a Digital8 camcorder.
BACKGROUND
1. Using a Hi8 camcorder, an analog exits the camcorder via the S-Video port (or Composite port). Then your SD capture device digitizes it.
2. Using a Digital8 camcorder an analog signal to exits via the S-Video port (or Composite port). Then your SD capture device digitizes it.
THE PROBLEM WITH DIGITAL8 CAMCORDER PLAYBACK OF HI8 TAPE
But here is the problem. The Digital8 camcorder digitizes the video signal, and then un-digitizes it as it exits via the S-Video port (or Composite port). This unnessary extra step makes the video look worse than using a Hi8 camcorder to play back the tape.
One can see an example of this at the 4:10 mark, where the logo looks blockier in the Hi8 tape version of the video exported with a Digital8 camcorder.
Devices used in this comparison video:
Sony TRV-66 Hi8 camcorder
Sony TRV-330 Digital8 camcorder
ATI All-In-Wonder 9600XT
This is excellent. These real world comparisons are very valuable to archivists looking to squeeze every last drop of quality from their rigs. Thank you. And keep them coming!
Definitely appreciate the comparison! I agree with your conclusion that there doesn’t appear to be any sort of conversion loss through the digital8 camcorder via S-Video and it does suggest an equivalent path in both without any extra digital conversions. This shows that a Hi8 camcorder really never has an advantage over a D8 camcorder for capturing S-Video/analog tapes. Only thing I can possibly think of would be that certain Hi8 camcorder have fewer SMT capacitors inside and therefore might require less maintenance. Your videos also show that you shouldn’t use the “DV stream/firewire” option for 8mm analog tapes for best quality. The difference in using DV capture seems much less pronounced for VHS in the capture comparisons I’ve seen.
For a future video, could you maybe compare Composite vs S-Video vs RGB Component type outputs in terms of image quality? I have a feeling that S-Video may be best. I think a deck needs to add a process for the 3 Component outputs that may degrade it compared to S-Video.
I think you're correct, the Digital8 camcorder is not locking on to any data signal on the tape and is therefore outputting signal straight to the analog output side of its DAC.
I'm not sure which Digital 8 camcorder you were using, but my Sony DCR-TRV740 does in fact convert analog tapes to digital first, when you choose the internal time base corrector option, even when playing through the S-Video port.
Also a thing i noticed is that the TBC and DNR functions in the digital 8 cam maybe is doing the colors look a bit worse or more washed out than the Hi8 camera playing back the tape, i noticed this with a analog video 8 tape from my 1985 CCD V8AF i have. So i did that test and the TBC function of the D8 camera affect the colors a bit.
You said you didn't notice a color difference between the Tide containers, but I definitely noticed a very slight difference. I confirmed with my GF and she noticed it as well. It's not nearly as noticeable as the Blue Screen example, but it's there. Maybe most people wouldn't notice such a subtle change though, it's easy to miss. I assume it's due to the brightness difference between the two, but that's just conjecture on my part.
What was also pointed out to me that I didn't even notice at first because I was so focused on the color was the jaggedness (aliasing?) of the DV example. It's most noticeable on the circle and text of the Tide logo on the zoomed in shot. Not sure if that's just due to any processing or if it's just normal playback jitter from one frame to another, but I thought it was worth mentioning.
I'm far from an expert myself, so ignore me if I missed something. I'm finding these exploratory videos on tape archiving to be useful and fascinating. Please keep up the great work!
Thanks for this. I find spotting the subtle differences in video colors, etc., to be maddening. So I appreciate your feedback here (and your girlfriend, too).
View it on a large HDTV, not a tiny computer window (or phone, or tablet), and it becomes extremely obvious, even to the uninformed masses.
At time code 4:04, notice how jagged that Tide logo is. That is very definite DV compression causing it. Chunky chroma aliasing is the most damning aspect of 4:1:1 DV compression. View that video at normal HDTV sizes, and it's extremely obvious, and even half-blind grandmas make comments on the degraded quality.
Recommendation: you should do a video on what not to do with digitizing VHS
Is important to say because every camera maybe does the playback a bit different with it's TBC in the brightness and colors. If i keep TBC off in my Super VHS-C camera the footage looks way more brighter losing some details in the DV AVI result because i use my digital 8 camera to transfer my vhs-c videos to firewire.
And if i keep TBC activated in my super vhs-c camera the video looks less bright and by that i can see more details and looks better.
TBC from the digital 8 camera does nothing here because it doesn't work as a "passthrough" TBC, only a few D8 models could do this but my TRV730E can't do this.
When things get this technical and there's very little to no difference in the footage you're working with, it's time to take a day off. I understand wanting to get the very best possible results however there are so many variables from capture to settings to playback sources etc. that you can never be quite sure and other decerning eyes may agree and/or disagree with your (or other's) findings. It can drive you around the bend and might even waste your valuable time. It's important to get the best results but it's also important to have a little fun with what you're shooting before it becomes a weary chore.
I highly doubt it, The analog video from the tape is first converted to digital for processing (TBC, DNR ...etc.) in a ADC stage before it gets sent out to a DV encoder for firewire output, The analog out is most likely converted from the ADC stage to analog in an extra DAC stage, It doesn't make any economical sense to have an unnecessary DV decoder inside the camcorder, because that's what it would require if the analog is derived from the DV encoder instead of the DAC after processing.
@@Capturing-Memories Thank you for this. I'm doing more tests that I will post next. In short, from basic VHS with very flaggy tape, out to composite in Digital8, out to FireWire, shows that it completely removes all flagging when TBC is set to on in menu, and removes almost all flagging when TBC is set to off. Are there two line TBCs in the TRV330 Digital8? The TBCs seem to work on passthrough...can that be correct?
@@videocaptureguide What I meant is, when playing back a tape, the signal goes like this:
For FireWire out: Tape -> ADC -> Digital processing -> DV encoder -> FireWire.
For Analog out: Tape -> ADC -> Digital Processing -> DAC -> Analog video socket.
If analog output is derived from DV, it must have to go like this:
Tape -> ADC -> Digital processing -> DV encoder -> DV decoder -> DAC -> Analog video socket. This is an unnecessary complication that adds to the cost of the camcorder.
The quality of the TBC seems to me to be much more important than the price, at least if you don't have a good TBC and can sell the camcorder again (home use). The manual for my SONY Hi8EX camcorder CCD-TRV65E (PAL) states which image content (copy + graphics) the line TBC should be left off for. I would rather use a frame TBC from the DVD recorder.
@@videocaptureguide Those camcorders don’t have just line TBC, they have other image stabilisations capabilities that are part of the digital processing.
@CapturingMemories Hi friend (this is Brad from VideoHelp). They definitely don't do DV Encode -> DV Decode for the analog path.
But how would it add to the cost?
If you play a D8 tape out an analog jack, it's already using a DV Decoder. This decoder would never have to be used by 2 signal paths at the same time, so switching upstream would allow 1 decoder to service any DV chain.
It was nice of you to test this for the commenter, but unnecessary. The schematics in the service manuals are proof that Digital8 cameras do not send their Hi8/Video8 internal playback through the DV encoder chip prior to analog output.
Unfortunately you conflate "A-D" with "analog to DV compression" in this video.
My DCR-TRV340 Digital8 cam definitely does "A-D-A" when playing analog tapes -- even when TBC and DNR are "Off". (In reality, chroma DNR is always-on, hence the scare-quotes.) The digitization is 8-bit uncompressed though. The service manual shows the common 27MHz crystal, so it's probably Rec.601 (720-wide YCbCr 4:2:2).
I've got a thread on VideoHelp showing the digitization and also the compression artifacts caused by DV Firewire capture of Hi8.
Thanks for this. Feel free to add the link to you post. Interested in reading it.
Converting internally to DV depends on the Digital8 camera model. Some most definitely do, while others have diagrams suggesting those do not. Thus the general advice is to avoid Digital8 as Hi8 players, for this reason. Too variable, unknowns, extra work and testing. If you want to deep dive, you can do so. But given that Hi8 cameras are usually cheaper to acquire than Digital8 cameras, it's somewhat moot. Few people have Digital8 tapes, and especially both Hi8 and Digital8, so a need to do both is tiny.
Good point. I found a Digital8 on Facebook Marketplace and the price was lower than elsewhere. Was curious about it and figured it would be good for comparison tests and in case someone has Digital8 recordings.
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I highly doubt the D-8 camcorder converts the video to the DV-25 codec prior to going out to the S-Video port. Having said that this video does not prove anything. The human eye is not going to notice any difference if it did. DV-25 is not going to make something orange turn red like you are expecting. What makes matter much worse is that you insist you ATI products are color accurate and the DV products are not yet you have no way to test out your theory. I have videos demonstrating the ADVC 110 and Intensity Shuttle are color accurate. You have seen those videos and commented on them yet you are ignoring the information. You need to invest in the Blackmagic Design Mini Monitor and the ADVC 110. I know a lot of people are telling you your videos are really good but they are severely flawed. I will have a video response demonstrating why they are severely flawed.
This would definitely harm color, because the ADVC boxes can only downconvert to DV. Not the full 4:2:2 "uncompressed" available from the ATI AIW. The AIW card has some of the most accurate color grading for VHS, as is allows both legal and illegal input values. No crushing of levels. Blackmagic cards have multiple known issues with VHS input, even with TBCs in use.