"Deinterlace renders" effects a progressive project?

Question

Does choosing the "deinterlace renders" selection inside the project settings tab have an effect on a project that is (was shot and edited in fcp) progressive? I shot my film using a JVC HDV camera in 25p mode, ingested and edited on fcp using ProRes 422 at 25p, and then sent to color for color correcting. I'm not doing the color correcting however, an operator is, and when she set up the project, she changed the quicktime export codec to Uncompressed 10 bit 422, and then checked the "deinterlace renders" box (she turned it on). The renders seem fine to me on the small monitor, however it will be transferred to 35mm film. I noticed that when I click and unclick the box in color, the shot which is selected changes slightly and I see a shift of movement in the parade and vector scopes. The operator insists checking deinterlaced renders does nothing to the images, and that she does that for every project she does... however... any other opinions on this? The manual says nothing on the issue. Thanks!

Answer 1

If you have 50 fields, then you are likely working in a "Segmented", not "interlaced" mode and that may explain why you see a little shift when checking the button. If the base video frame rate is 25, then each frame is still made of two components -- interlaced means they are temporally displaced, segmented means that although the frame was composed progressively, half of it is field 1 and the other half is field 2. You can get away with screwing up the dominance because there is no temporal displacement -- no one would notice if field 2 came before field 1-- there is no bouncing ball that would appear to stutter back and forth...
True progressive is actually still kind of rare, especially in tape formats.
Film isn't either progressive or interlaced -- it is the whole frame at a time as shot in camera.
A laser recorder does scan a progressive image onto intermediate or negative, and the CRT film recorders display whole-frame images through a progression of R-G-B filters. The lasers are better in my experience, both for consistent contrast and color accuracy.
jPo