Chromakey questions

doncarp wrote on 9/24/2003, 10:52 PM
I have read the manual and searched the forum, but have not found an answer to my question.

I just used the chromakey feature for the first time. I followed the manual step-by-step but was not seeing the expected results in the preview window. After much frustration and many attempts I decided to render the region with the chromakey effect. The rendered AVI had the proper effect.

I am almost sure that when I saw SPOT demo VV in Cleveland that he just dragged two clips onto the timeline and the preview window (projection screen) showed the proper results. In my case I was using clip art on a green background. The rose in the clipart needed to rotate and float back and forth until it reached the desired location. It is difficult to move the object to precise locations if you cannot see the second track for reference.

What am I doing wrong?

Comments

TheHappyFriar wrote on 9/24/2003, 11:28 PM
I'm not sure what you're saying. It would probely be easier if i had a screenshot to look it... But here goes.

Could you of possibly muted the bottom track? Also, (i' m assuming the rose it on the top track with a background on the bottom) if you plop the background on the bottom track, do you see it in the preview window? What about after you plop the rose on rhe top track? After you apply the chroma key? If the chroma key it set up properly, you should be able to see through it in the preview window.

doncarp wrote on 9/24/2003, 11:35 PM
Q: Could you of possibly muted the bottom track? A: NO
Q: Also, (i' m assuming the rose it on the top track with a background on the bottom) A:YES
Q: if you plop the background on the bottom track, do you see it in the preview window? A:YES, before the rose on green background goes on the track above it.
Q: What about after you plop the rose on rhe top track? A:Just the rose on green background.
Q: After you apply the chroma key? A:Just the rose on green background.
Q: If the chroma key it set up properly, you should be able to see through it in the preview window. A: I don't
BillyBoy wrote on 9/24/2003, 11:58 PM
When you stack one track on top of another the uppermost track hides the lower tracks. To overcome that drag down the opacity level of the upper track and the lower track will bleed through. To do this hover your mouse over the top edge of the top track until the cursor changes into a two headed arrow. Now grab hold of the blue line you see which controls the opacity level. As you grab it (click left mouse, hold down and drag) you'll get a readout of the current opacity level. Let go when you can see enough of the underlying track.

For chromakeying, the settings of the threshold sliders can be critical depending on the object. They interact so you got to move both back and forth for the best effect to make the color you want transparent.

Of course you used the eyedropper tool to pick the color from the preview window you want transparent and you remember to return the opacity level to 100% before rendering.
josaver wrote on 9/25/2003, 3:22 AM
Have you checked the bypass efects on the preview window???

Josaver.
Tom Pauncz wrote on 9/25/2003, 9:53 AM
I am just going through chromakeying for a project, simulating a 'sports desk' for a non-prof junior soccer club video. The green screen background is less than perfectly lit.

1. Apply Secondary Color Correction FX and use the 'Saturate Green' preset from the pulldown. You can tweak this with sliders.
2. Apply Chromakey FX and choose 'Pure green' from the pulldown. Again, this can be tweaked with sliders.

The FX chain has to be in that order.

Bon chance,
Tom
Spot|DSE wrote on 9/25/2003, 10:14 AM
Don,
Sounds like you may have had the tracks in the wrong order? or perhaps forgot to re-check the Chromakey box? The way I demo'd it there in Cleveland was to uncheck the box, get the color sample, then recheck the box in the FX dialog.
HTH