ALL: 1080i v 720p??? when trying to avoid jello effect of moderate speed panning

[ELN614]

As some of you know I shoot horses running in a field. Last year I shot it at 1080i (for the first time in HD.. all other years it was in SD).
I am thinking of shooting it at 720p since A) they only watch these videos on TV no larger than 40" (playing as media files - not DVD) and B) I need to convert down to H.264 for web viewing, anyways.

I did a little test video shot since I am trying to find a good scene profile to give good saturation and squeeze down the high contrast I get on sunny days. (I should start a new thread to see what people found is best for that, but I digress.)

In my test I found parts of the image to have what I feel is a bit of a jello effect. I don't recall seeing that in last year's 1080i. So does the interlacing help eliminate the perceived jello effect vs the progressive?

other info: Not sure if it matters but I shoot at a shutter speed of 120. I am afraid if I shoot any higher I might get a strobing effect. I might bump it to around 250 to see if it still looks 'smooth' when watching.

essentially... what should I shoot my horses in? 1080i or 720p????

Please Note: I have the AC130 so 1080p is NOT an option on the camera. So don't suggest 1080p!

 

[Rainer]

I also shoot horses. The jello comes mainly from the CMOS sensor(s). As far as i vs p, there's an astounding amount of conflicting information out there. My thinking is that since with i you are capturing 60 fields you are getting twice as much motion information for your 30 frames as you would with 30p, so on a interlaced display it should look smoother. With a p display, it's going to depend on how your display handles the interlaced frames - whether it drops one field or combines them. On YouTube, I understand it's one field dropped and i and p will look the same. I'm not pretending to be an expert in this, it's just how I understand it now, so if I've got it wrong, please chime in.

You can also change the fields into frames with Virtualdub and get 2X slow motion at half resolution. It's not the 720p that's significant, it's the 60fps. You can combine two 720 60fps to create 1080i, so if you don't mind a bit of work in post, it doesn't really matter if you shoot 1080i 30fps or 720p 60fps. As you've seen, you're safe shooting at 1/120th sec at 30fps. If you're going to display in slow motion you're OK at 1/250th sec, otherwise it does start to look stroby, but if you're tracking the horse it affects the background more than the horse so may not matter, you really have to experiment to see what looks OK to you. With your viewing setup I don't think many people could see the difference between 1080 and 720. I don't think there's any way to deal with the high contrast on, say, a sand arena in daylight, spotting the horse with a reflector isn't practical and may lead the rider to damage you or your equipment. Underexposing slightly helps a bit.