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-   -   Confusing FCP / HDV problem (https://www.dvinfo.net/forum/final-cut-suite/89881-confusing-fcp-hdv-problem.html)

Marco van Belle March 25th, 2007 10:53 AM

Confusing FCP / HDV problem
 
Hi all,

I've shot an HDV music promo and I'm having some problems in FCP 5.0.1 on an iMac G5.

Basically, I'm getting what I can best describe as 'digital abberations' that are very apparent - especially on darker areas of the frame (esp where they meet lighter areas) - (by very apparent, I mean to any trained eye). Basically I've got little whirls that are digitally distorted (like fingerprint whirls) that undulate on background objects and surfaces. In simple terms they are like waves of pixels. Sharp foreground objects are fine. I've checked, and these are not on the tape at all. So it's something to do with me and my system. The problem is not due to my monitor / display - these waves / whirls carry on to Quicktime movies and DVD's.

At the moment I can't post any grabs (not online at home and only this work pc) but details as follows:

Shot on Sony Z1 in HDV 1080i50 with the SGPro 35mm converter - as mentioned, no probs on tape.

Import settings were to import as HDV (not intermediary codec) from a Sony 1080 50i device.

Timeline settings are HDV 1080 50i - but the problem is on the imported rushes, not when dropped onto timeline.

I can't work out what setting I may have got wrong that would allow me to import all the footage etc and edit it / play in timeline without issue, yet creates these problems?

Any suggestions greatly appreciated.

Boyd Ostroff March 25th, 2007 04:24 PM

How are you viewing the footage when you see the problem? Are you using Digital Cinema Desktop? Under some conditions that can give a very inaccurate view of your footage. I have found that dark footage sometimes looks really bad, like it's very noisy when in fact it's ok.

Assuming you don't have any sort of HD capture card for viewing, try exporting back to the camera and watch the tape on a good monitor connected via component video.

Marco van Belle March 25th, 2007 04:59 PM

Thanks Boyd
 
Very valid point - thanks Boyd.

I'm running an out-of-the box iMac G5 setup (bough vv cheap when pentiums came out) with no bespoke HD card.

I haven't played back to camera - but I have exported quicktime and burnt to DVD (intermediate codec & mpeg 2)- both of which displayed the same problem. Would going back to tape be different?

Also noticed further issues which are clearly related - and make me wonder if I have a setting awry somewhere:

When digitizing the footage and watching it play in the log and capture window on my iMac screen it looks identical to what is on tape in camera - sharp, seemingly faultless HDV.

However, once digitized and opened from the clips bin in FCP, the same footage is notably darker, more contrasty, and displays the digital whirls / abberations that I've mentioned in darker and dark/light transitional portions of the frame.

Basically, there is a clear degradation (sp) in quality when played back as a digitized clip as opposed to when played from camera onto the same screen.

As mentioned, I'm still on a big mac learning curve.

More input very gratefully appreciated.

Marco van Belle March 27th, 2007 09:17 AM

Additional Idea
 
Ok - I spent all last night online looking at *ahem* other forums / web articles etc, and cannot find any references to a similar problem. Of course, I could be reading them wrong.

I found this post from Bob Hart in response to someone else's problem:

"the images in HDV may already have some compression artifacts from the high rate of variation between frames in the form of groundglass texture (grain), which can be a characteristic of 35mm relay footage.
A high shutter speed, a coarse groundglass and a high contrast image might aggravate a "grain" tendency."

Anybody think this migth be a viable consideration with my issue detailed above?

Marco van Belle March 28th, 2007 08:40 AM

OK - last solo post
 
ok - I seem to have a thread of my own here and I apologise to mod's for my continued posting, but this is a really odd problem for me and I have a project to deliver quite urgently.

I have now managed to play my HDV timeline back to tape.

It is faultless on the tape playback. So the problem is only on my iMac screen and any media like Quicktime movies, mpeg2's that I create from the timeline.

An Avid editor with some FCP experience has told me to try making a 'Quicktime reference' movie. Which will reference the rushes rather than the timeline? I have searched but cannot find this 'reference' option.

Any help based on these new developments very much appreciated.

Martin Saxer March 28th, 2007 09:38 AM

Save as... in QT Pro

Martin

Liam Hall March 28th, 2007 04:14 PM

File>Export>Quicktime - Make sure the "Make Self-Contained Movie" is unchecked and you're good to go.

Liam.

Marco van Belle March 29th, 2007 06:14 AM

Thanks guys
 
You're spot on as to how to export the Qtime reference movie.

Unfortunately when I tried it last night (UK time) it displayed the same problems as the footage in the timeline.

Yet still the material doesn't appear to exhibit it once played out to tape.

I've tried AIC and rendered to an SD timeline to go to Mpeg2 & dvd and again it persists.

I would naturally assume that it is just an issue with HDV and the conditions we were shooting in (colour of walls - where it shows up the worst - and black clothes / movement) but I keep coming back to the fact that it ain't on the darn tape. However, I am not watching the tape back on an HDV monitor, only SD and LCD screen. So it may be that I'm only getting an accurate representation of the problem with the HDV once it is in FCP?


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