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Excess Chroma, Broadcast Safe Filter & the Vectorscope
Howdy Cowpokes,
When finishing my program, I thought it would be easier to nest my entire show and apply the Broadcast Safe filter instead of going through shot by shot and using the color corrector to adjust any illegal chroma values.
When I do nest my sequence and apply the filter to the entire sequence, FCP displays the green checkmark when I choose view Excess Chroma, indicating that my chroma levels are legal.
BUT
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6 Replies
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It’s considered lazy and ultimately not quite accurate. 🙂
Ed (who also uses the same workflow occasionally)[Pseudojag] “Can anyone comment on whether the application of the Broadcast Safe filter to the entire program is a lazy and ultimately incorrect way of respecting legal chroma values
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YOu might have a small spike that hits 105 but can’t see it due to the graphical nature of the Vectorscope. So when the Broadcast filter clamps that, you don’t see it happen. All the levels don’t shift down, the filter just clamps down everthing above 100, and below 0.
If this is really for broadcast, you will be doing yourself a favor by going shot by shot and doing a color correct.
Shane
Littlefrog Post
http://www.lfhd.net -
Ive delivered almost 50 one-hour HD docs for broadcast and always throw the BS Safe filter on a final nest of the entire sequence…never shot by shot…I’ve set it up to clamp above 100 and start at 90….I’m only chiming in here to say what has been acceptable for us and wouldnt want to have to do it shot by shot….I guess it depends on how strict the receiving party is…
Sterling Noren
Owner/Writer/Producer/Editor
WideWorld HD Productions
Seattle, WA -
Color correct the proper way: shot by shot. The BS filter is only for “fail-safe” purposes. You don’t do it shot by shot? That ain’t right.
Kevin Monahan
Take My FCP Master’s Workshop!
fcpworld.com
Pres. SF Cutters -
This may help: (from KenStone)
Edhttps://www.kenstone.net/fcp_homepage/cc_legal_fcp4.html
Broadcast Safe Filter
This is an interesting filter that is also included in the Color Correction Bin. The purpose of this filter is to limit the top end of an image, the white values. Using this filter can help to clamp values above a certain point, to ensure that you are still “legal”. I find it very important to have the waveform monitor open while making adjustments with this filter. I think that people tend to think of this very literally as a “Legalize” filter, and do not contemplate just exactly how it is “legalizing” the image.
This filter approaches the task by taking values above a certain point and clamping them, or “cutting them off”. It also will give you the flexibility of determining just where that cut off point is, as well as where it starts to pull higher end values down the scale, so basically shifting the high end a little darker.
You should use this filter with caution. If you color correct so that a majority of the highlights fall fairly high on the scale, above 100, and then apply this filter to cut off the top end, you may end up with undesirable results. This will cause a flattening of the image in the highlights, which appears as dull, flat sections of white, instead of gradations of highlights. This is similar to what you will find when over-exposing while shooting video. There will be blanket areas of white, with no detail in them.
Highlights with Gradation
Flat Highlights
When using this filter, I suggest that instead the whites should roll off a bit, before being clamped. This can be done while using the Color Corrector 3 Way or Color Corrector filter. Adjust the highlights so that the majority of spikes fall below 100. If the top end of a few spikes still fall above 100, but you are happy with the image as a whole, then this would be the time to apply the Broadcast Safe filter.Whites not clipped (without filter)
Whites clipped (with filter)
On the Filters tab, there are several options, but the default is often sufficient.
If you feel brave, then you can set the drop down menu to Custom. Once this is set, use the controls under Luminance and Saturation Limiting to control the clamping point, adjust the range of the falloff, and where the top end sits on the scale.
As mentioned above, this filter should be used with caution when trying to create natural scenes. It is generally more pleasing to see gradation in the highlights, even if it is subtle. If one of the reasons for raising the white levels was to bring more contrast into the scene, then this can better be accomplished by a well balanced scene, then by overdoing the whites. Having a true black in the frame along with a true white will give the image more punch, and more of a feeling of intense white in the highlights.
On the other hand, the Broadcast Safe filter is a great aid when trying to create high contrast looks. With a color corrector filter, then a Broadcast Safe filter, you can keep pushing up the Mids and Whites sliders without the whites going above 100.
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[Kevin Monahan] “The BS filter is only for “fail-safe” purposes.”
BS filter…I like the sound of that.
Shane
Littlefrog Post
http://www.lfhd.net
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