“Ghosting” on downconverted text

[Tim Mclaughlin]

Forgot the details:

FCP 5.1.4
OS 10.4.10
Quad Core G5 2.5 GHz
Kona 3 with K-box

Downconverting DVCProHD 720p via HDSDI to DVW-500.

All standard def stuff looks GREAT. 10 bit Uncompressed SD does NOT have this problem.

This seems to be a down conversion problem only.

Tim McLaughlin
Avid and Final Cut Pro Editor

[Paul Provost]

are you downconverting by just rendering out in an fcp timeline, or are you downconverting an hd timeline using the Kona card output to a deck?

Paul Provost
http://www.postandbeam.tv

[Tim Mclaughlin]

Downconversion is happening entirely through the Kona 3 card.

I’m performing “edit to tape” from my HD timeline and having the Kona card downconvert via SDI as either letterbox or anamorphic and add the pulldown.

[Arnie Schlissel]

I have not seen that going from a 720P timeline to beta via the component out on a Kona 3.

What kind of monitor are you using for the downconvert? I try to monitor downconverts on a CRT, the LCD that we use doesn’t show the whole story with SD interlaced footage.

Arnie
Now in post: Peristroika, a film by Slava Tsukerman
https://www.arniepix.com/blog

[Aaron Neitz]

Now I’m confused… you said you were using Kona LHe or Kona 3?

Can you digitize a digibeta that you made with these ghosted text and post a still image for us? I think that’ll help tremendously.

[Aaron Neitz]

Also like I asked earlier, are you certain you have broadcast safe titles?

The only reason I ask is on an old project for HDCAM-SR which we were peaking at 110 (this was for filmout, no broadcast safe needed to be adheared to) any downconvert to SD showed a weird ghosty/ringy quality in solid graphics and gradients. Disclaimer: this was using a Blackmagic card

[Gary Adcock]

[Aaron Neitz] “Also like I asked earlier, are you certain you have broadcast safe titles? “

Aaron

Good question, I would Like to also ask about the fonts being used. Thin or fine fonts
do not look good in SD, while the fine detail holds up in HD the inter-field blurring brought on by not having enough data when doing a conversion can bring this on.

My test – Use a standard title in SD and the same in HD downcoverted should look the same, and in all of my tests they do. Only on very fine text detail when doing an HD downconversion does it break apart or ghost. – it means that your font is NOT suitable for SD viewing.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD

[Tim Mclaughlin]

Thanks for the feedback and questions guys.

Here is a link to hi-rez JPEG files as well as a zipped archive of TIF files that I’ve compiled.

One file is the original HD, one is a 10 bit capture from the SD downconvert, and one is a totally unfair comparison by taking the HD frame and resizing it in PhotoShop.

As a test, I readjusted the levels of the name keys in AE (to a range of 16 to 235), and I was still seeing the same issue.

I just need an answer on how to fix this – or if it’s even fixable. Am I doing something wrong? Does DVCProHD always look like crap on downconversions? Is there something wrong with my card?

Tim McLaughlin
Avid and Final Cut Pro Editor

[Aaron Neitz]

Ah, I see

I see this on downconversions too. It’s a function of that strong primary color, white type, and hard edges. There’s probably some YUV maths involved in going from a 4:2:2 HD space into a 4:2:2 SD space… That’s why Photoshop does such a good job – it’s pre-sampling your HD as 4:4:4 RGB.

Did you try letting Compressor do a downconvert? Or dropping the HD timeline into an SD with Best rendering?

[Tim Mclaughlin]

Letting Compressor or FCP handle this makes it look even worse. The interlacing artifacts are terrible.

I’d take ghosted titles over those 2 options.

Tim McLaughlin
Avid and Final Cut Pro Editor