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Deinterlace for TV or not?
Hi, looking for some advice please.
I make very short promo clips (no more than 60-sec) for TV shows (PAL) in Adobe Premiere Pro. These TV shows – in the original material – either have the frames blended or aren’t (it could be a case that the lines are far less noticable. Some of it just doesn’t look like the frames are blending to me).
Now, I always tick the “Deinterlace Video Footage” box in the export settings when saving, regardless of the footage.
Should I really be doing that? Should I select “No Fields (Progressive Scan)” instead for certain things, or always?
Incidentally there is no noticeable drop in quality on the PC or on TV.
Also the clips always play back fine on my standard TV with no juddering. Would this be the case for other TVs? Also what about new LCD TVs?
I realise that certain TV stations play in a mix of fields, and even a video clip itself (like an advert) can be in a mixture of fields – going from teeth to not – in different shots.
So, does this really matter? Any advice welcome. Thanks.
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6 Replies
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Hi Brian,
The moment you deinterlace footage you lose half of the information making that image.
TV never needs to be deinterlaced. Interlacing issues only show up if they are in the wrong (conflicting) order upper (odd) instead of lower (even) first.
Leave the setting to what ever the footage is.
1. Export the setting the project is in.
2. Check the Project> Project Settings> General.
3. That will probably be the default setting as you export.
If you do choose the opposite field dominance you’ll get the ugly footage shifting all over the place.
– Jon 🙂 -
You lose a percentage of the vertical resolution when
when deinterlacing not an overall loss. In layman’s terms,
it’s about 20%.Re deinterlacing for new televisions: there’s no yes or no
answer – a lot of the second-gen HDTVs have internal
propriety software (quasi-frame interpolation, for example)
which is impossible to predict in post. Best advice, as
always, is a little bit of R @ D. Test various edits on
as many sets as possible. What looks right probably is right.
And whilst your checking your fields, it’ll be a good time
to check your broadcast safe levels and audio levels too ;).Fast action such as sport is best left as interlaced.
Darren.
x-gf.com
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OK, thanks both for the advice. So, really I’m just keeping it as the original. If it’s interlaced, then keep it interlaced.
To be honest, not all of the original films have the lines/interlaced. eg: – two different scenes aren’t being blended together to create one frame. The different scenes are their own individual frames.
I guess this means these are already de-interlaced in the original? Should I then be interlacing them here?
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Regarding the project settings. This was just the default options I believe. I’ve had Premiere for a few years and cannot remember tampering with these parts. I don’t usually alter defaults on any program.The project is set to “Lower Field First” (PAL of course). So, I guess I should rendering them as as “Lower Field First” and leaving the “Deinterlace Video” unchecked?
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Best to know what your source footage really is. Could be that you are not seeing fields because it was originated on film.
But, for standard-def TV output, PAL and NTSC are both interlaced.
-jeff
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What you just said, leave the deinterlace box unchecked. If you have a mix of footage with interlaced and progressive the interlaced settings of the project will sort it out on export. The only time to set it to progressive is if the project is prog and the screening will happen that way too.
New TVs have a way of dealing with broadcast interlaced footage, most of it is anyway.
– Jon 🙂 -
OK, thanks for the help guys.
My material is actually on DVD or drives – so all digitally. Some of it is interlaced and some isn’t.
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