View Full Version : Interlacing problem in Premiere 1.5.1 - electrostatic sparks


Dan Robinson
February 15th, 2006, 09:56 PM
I'm currently working with some footage of Wimshurst and Van De Graaff generators in operation. These are the 'static electricity' machines you see in science museums that create big sparks and make people's hair stand on end.

I'm having a problem with some sequences where the machines are outputting rapid-fire sparks. These sparks are very quick and are only occupying one half of an interlaced frame, and are randomly on either the even or odd half of the frame. No matter what I do, I only get half of the sparks to appear in the final project (in this case a WMV file for the web). The 'reverse field dominance' option in Premiere just causes the other half of the sparks that weren't showing up before to be visible and vice versa.

I've tried both Premiere's Frame Hold and Field Options settings and the interlaced processing in the WMV encoder, but still only half of the sparks show up in the final wmv.

I could just chop up the video into a hundred individual clips with each spark and apply 'reverse field dominance' to the ones that are needed, but I was hoping there would be a setting that would cause all of the sparks to be visible.

Dan Robinson
March 1st, 2006, 10:34 AM
Is there a way to deinterlace frames where the even and odd frames are combined rather than one or the other eliminated altogether?

Christopher Lefchik
March 3rd, 2006, 12:10 PM
Unless you added a DeInterlace filter as a Pre Encoding task in the Adobe Media Encoder and chose either the Upper or Lower field, both fields should be combined in your encoded WMV file. You can check this by going to a section with fast movement and looking for a combing effect. If you see this, then both fields have been combined. If not, then somewhere along the way your footage is being deinterlaced. Unless you added the aformentioned DeInterlace filter in the Adobe Media Encoder and chose one of the field options, then the deinterlacing is happening in the editing process.