What is this?

[Hugh Mobley]

Pls take a look at this clip and maybe someone can tell what is going on, the second part of the clip where the girl is on bas then runs off its a double image, I shot 25 min and alot of the bat swings etc were like this. I was shooting apeture 8, 0 gain and 725 shutter speed, manual, no nd filter. Auto called for 8-0-and 1000 shutter speed, I locked the stetting and was on a tripod. Any ideas? Is this rolling shutter?, I have not experienced this before, only when shooting 24 p, this was 1080i, Is it is the camera or the capturing, we captured with cineform into vegas.

[Bryan Shelley]

I don't think your clip made it to your post. Sounds pretty interesting though, from your description. I'm wanting to see it.

Bryan

[K.C. Luke]

Yes did not see any clip or link...

[Sebastian Pigott]

Did not see the clip but I'll take a shot in the dark. The camera was on a tripod.....was steadyshot turned off?

[Hugh Mobley]

what am I thinking, thought I put it up:

http://www.hughmobley.com/test2.html

[David Tamés]

Hugh, Looks like the double image you see is the result of interlace in the original video. Since each field is recorded at a different moment in time, fast motion will register as a double image, since the two fields are 1/60th of a second apart from each other. You don't see distinct interlaced lines in your QuickTime frame due to the codec used to make the QuickTime blended the two fields to reduce the effect of interlace and it's tell-tale jaggy edges on motion, but with field blending you still see double image w/ fast motion. Also, each of the fields is very crisp and sharp, that's a result of the high shutter speed, which eliminates the motion blur you would expect to see with fast motion when the shutter speed is set lower.

Frame from your video copied below for reference.

In this day and age of wonderful progressive scan cameras, there really is no reason to shoot interlaced unless (1) you like to cause more work for your compressors downsteam from the camera or (2) you need to capture fast motion and can't shoot 60p or (3) you like ye olde 60i video look (I'm being playful, I'm not trying to start a 24p vs. 60i vs 60p vs. ... debate).

[Hugh Mobley]

I have been shooting interlaced because of lousy results shooting progressive, which might have been better with higher shutter speeds, we capture with cineform and deinterlace, but apparently this didn't do it for this clip. The other camera we used was a Z1 and it didn't show anything like this. is it your opinion to shoot progressive, maybe 30p and keep the shutter speeds up for fast moving subjects.

[Adam Gold]

Originally Posted by David Tames

In this day and age of wonderful progressive scan cameras, there really is no reason to shoot interlaced unless (1) you like to cause more work for your compressors downsteam from the camera or (2) you need to capture fast motion and can't shoot 60p or (3) you like ye olde 60i video look

Yeah, that #2 is the killer. There is no 1080/60p cam in this price range, so that's the key limiter.

Hugh, shooting 30p in this situation will eliminate the double image but may look jittery when played back. You should try it and let us know what you think.

FWIW, I shoot a lot of baseball but never shoot at anything other than 1/60 and never deinterlace, and I've never had this problem.

[David Tamés]

Originally Posted by Adam Gold

[...] FWIW, I shoot a lot of baseball but never shoot at anything other than 1/60 and never deinterlace, and I've never had this problem.

If you shoot 60i for fast motion purposes, and 60p is not an option, try compressing the video using a better de-interlacing technique, which is available in most compression applications. For example, I personally use Compressor (in Final Cut Studio 2) which provides very good deinterlacing results when I create a set of custom resizing/deinterlace settings like: "Resize Filter: Best (Statistical Prediction)" and "Deinterlace: Best (Motion Compensated)" and "Adaptive Details: ON" and "Output Fields: Progressive" and "Rate Conversion: Best (High Quality Motion Compensated)" etc.

These kinds of settings dramatically increase the time to create a compressed progressive scan video from your 60i original, if you don't have a fast machine you will be waiting a long time for your compressed video, however, the results are dramatically better.

Experiment with a short segment that displays the interlace issues. Look for the similar options in whatever compression software you're using.

[Seth Bloombaum]

While David's suggestions about good alternative workflows are certainly valid...

This indeed looks like an interlacing issue, yes. But Cineform deinterlace can do better than this. Possibly the field dominance/field order setting was wrong in the deinterlace. Try again and look for this control. It needs to be matched to the field order of the original footage.

I will disagree with some of the above and suggest that 60i is a very good good format for sports-like motion. Were it me, I would not be going progressive at all, except in prep for slomo sequences. Of course, I don't have access to a 60p camera...

[Adam Gold]

Originally Posted by Seth Bloombaum

I will disagree with some of the above and suggest that 60i is a very good good format for sports-like motion. Were it me, I would not be going progressive at all, except in prep for slomo sequences. Of course, I don't have access to a 60p camera...

That's what I was trying to say, but Seth said it better than I did...

[Hugh Mobley]

I did not capture this personally, but I will as soon as I get the tapes back. I have not had this issue in the past, although I have seen a double image on some birds wings. there is possibility it was captured differently than the way I do, I'll see. although I know cineform was used. the girls feet were not moving all that fast where the camera couldn't keep up, The girl running around the bases didn't present this issue. We have over an hour of this softball and only need a few minute for the TV promo. so this clip will probably not even be used. just needing to find out more on how camera works with motion and the best way to shoot.

[David Tamés]

Originally Posted by Seth Bloombaum

[....] Cineform deinterlace can do better than this [...] I will disagree with some of the above and suggest that 60i is a very good good format for sports-like motion. Were it me, I would not be going progressive at all, except in prep for slomo sequences [...]

Essentially, if you shoot 60i and deinterlace, then it's not really 60i anymore, so maybe we agree more than we disagree. I do appreciate the crisp "motion capture" of 60i, but I'm not crazy about interlace artifacts. Maybe it's aesthetics, I like a little motion blur in my images.