Red/cyan vertical color lines on right of VHS frames?

[aramkolt]

I've seen a variety of threads discussing discoloration on the extreme right or left of a video frame for VHS and I ran across it today in doing some testing, though I believe the signal is coming off of the VCR this way rather than being added by any of the inline devices. I will get around to trying the same tape with some other VCRs and capture devices, but thought this was odd.

What I noticed is that the extreme right most edge has either a pink or cyan color stripe that alternates in color exactly every other frame.

Wondering if the "every other frame" thing has been described before (and if it has a technical name) or if that could indicate anything in particular?

The explanation I've seen before is that when those bars occur, it is due to the original device that recorded the tape.

Couple of clips are attached - one of the original ProRes file and one that's been cropped and upscaled slightly to 720p59.94 in StaxRip. It's a bit hard to perceive the alternating colors when the video is playing because your brain kind of averages out the opposite colors.

Chain is AG5710 with TBC on (set to Edit mode) -> Snell and Wilcox CVR250 (Functions as a frame TBC and 10 bit DAC/SDI converter) -> AJA KiPro recording the 525i/480i SDI into ProRes 422 while preserving the interlacing. What I like about this chain is that it doesn't require a capture PC and there's only one analog to digital conversion outside of the VCR. There's also higher bitrate ProRes 422 HQ available to record to as well on the unit. It's also technically Mac friendly, though deinterlacing options are more limited there as I haven't been able to get Hybrid to work on modern Macs reliably.

Any criticisms of the video quality itself are also welcome. Something like that will be part of my massive comparison on different chains once everything is tested and I come up with a more defined testing protocol.

[Gary34]

Quote:

AG5710 with TBC on (set to Edit mode)

This three-way switch, located on the AG-1980's flip-down control panel, controls several options.

The "edit" switch on the Panasonic AG-1980 operates differently from the "edit" selection found on many JVC VCRs. On a JVC VCR the "edit" position provides a relatively "unretouched" playback image. The "edit" position of a JVC doesn't apply any artificial filters or sharpening to the picture. However, the Panasonic AG1980 "edit" switch is used for a different function.

On the Panasonic AG-1980 there's an "edit" connection on the back of the unit. This connection is used to join two AG-1980s together for editing, or when the AG1980 is recording from a source such as a camcorder. When they're connected like this, you place the DETAIL/NORM/EDIT switch on the front panel in the EDIT position. For normal playback the DETAIL/NORM/EDIT switch should be in the NORM position, per page 28 of the AG1980 instruction manual.

If you playback a tape on an AG-1980 in the "edit" position, it's normal to see some noise and a somewhat blurrier picture. You'll see this on all AG1980's when in the "edit" mode. On the AG1980 schematic, the "edit" position bypasses several important parts of the chroma-video circuits to allow it to "mate" with another AG1980. If you view the "edit" video output on a waveform monitor, you'll see that resolution is reduced in a bad way. Again, use "norm" for regular playback as suggested in the instructions, "edit" position only your AG1980 is recording from another source. That also applies to the 5710.

[aramkolt]

Good point - I'll have to retry in Normal playback mode and see if there's a difference in the output. Detail didn't seem particularly bad to me, but I'll be curious to see if it sharpens up in normal mode. I will say that I didn't see too much in the way of line dropouts or chroma abnormalities - You could be onto something though that the cyan and red field tags do have something to do with a copying process that I am unaware of.

Thanks for the input. I always thought Edit mode bypassed extra processing which is typically better for VHS archival, but I could be wrong for sure.

[lordsmurf]

EDIT does disable chroma NR. on JVC, not Panasonic, nevermind.

[Gary34]

It’s just a copy and paste from Tgrant’s website.