Question about projectors

[seven_deuce offsuit]

Do projectors shoot with progressive scan or interlaced? I'm going to be showing one of my videos at school and I was told it was going to be shown on a projector. If it was progressive and my video was interlaced, would I have to change my video's field order to progressive to get the same smooth movement in my video?

[edDV]

Do projectors shoot with progressive scan or interlaced? I'm going to be showing one of my videos at school and I was told it was going to be shown on a projector. If it was progressive and my video was interlaced, would I have to change my video's field order to progressive to get the same smooth movement in my video?

We would need the projector model number to get specific but most projectors will take either interlace or progressive source and convert internally to its native scan format.

Any composite or S-Video input is by definition interlace. A VGA input is by definition progressive. If you are feeding 480i from the computer to VGA, your graphics card chips are making the interlace to progressive conversion.

Bottom line: You don't need to change your video.

[seven_deuce offsuit]

I was reading an article on progressive scan on wikipedia and it said this:

Progressive scan will have half the frame rate of an interlaced scan's field rate, at a given line rate. This reduces motion smoothness, which may be a disadvantage in fast-changing images such as sports coverage. To maintain the same smoothness, double the line rate is required.

I don't know if that would matter for my video if you said was true. Since my video is interlaced I thought it would lose smoothness at a projector shooting at progressive scan. I remember showing a slideshow once on a projector and the movements and transitions weren't smooth. It was also an interlace video so I'm assuming the projector was progressive.

[edDV]

I was reading an article on progressive scan on wikipedia and it said this:

Progressive scan will have half the frame rate of an interlaced scan's field rate, at a given line rate. This reduces motion smoothness, which may be a disadvantage in fast-changing images such as sports coverage. To maintain the same smoothness, double the line rate is required.

I don't know if that would matter for my video if you said was true. Since my video is interlaced I thought it would lose smoothness at a projector shooting at progressive scan. I remember showing a slideshow once on a projector and the movements and transitions weren't smooth. It was also an interlace video so I'm assuming the projector was progressive.

This depends on the projector and the same issues would apply to a progressive television.

If the projector is native interlace (e.g. DLP) then progressive is converted to interlace. If the projector is progressive, interlace to progressive conversion can be done crudely (e.g. 29.97i to 29.97p blend deinterlace) or done in various advanced "line doubling" modes (e.g. 29.97i to 59.94p adaptive, motion compensated, motion predictive, etc. deinterlace).

In other words, it can be done in a way that preserves motion resolution. It all depends on the technology in the projector.