View Full Version : A1 Ghosting


Steve Lewis
July 21st, 2008, 09:41 PM
Hey Fellas,
I seem to get a lot of ghosting and motion blur when I shoot with my A1 (I am shooting in 60i). Here is a video to check out: www.vimeo.com/1336452 Is this normal? Any suggestions?
-Steve

Andrew Kufahl
July 21st, 2008, 10:45 PM
Hi Steve,

I'll state what is probably the obvious... Ghosting was apparent when there was a lot of quick movement from the dancer, and probably most apparent when there was a lot of quick movement from the dancer and the camera (i.e. the camera trying to keep up with the dancer). That leads me to wonder if you remember what shutter-speed you were shooting at?

The only other thing that kind of stood out to me was that even though you say it is 60i, I didn't really see any interlacing, therefore I'm wondering about your render settings? I downloaded your video and pulled it into Sony Vegas to see what I could get, and it looks like you may have rendered to 30p? Does that sound correct? If so you'd probably want to ask around to find out what settings other people that use the same software as you are doing. What software are you using to render?

Andrew

Ivo van Aart
July 22nd, 2008, 02:54 AM
To the eye, this doesn't seem to be 60i. That could be the problem. This much ghosting is not normal, even for videocamera's.

Peter Szilveszter
July 22nd, 2008, 04:11 AM
Looking at it seems a few possibilities, shutter speed bellow 1/60, rendering method to de-interlace is not right or even maybe the Noise Reduction is turned on, although not sure with that much light it would do anything but I have it always off so don't know if that has impact.

how does it look if you play back directly from tape to your tv?

Steve Lewis
July 22nd, 2008, 04:31 AM
Hey Thanks for your help:
Some more info: I am using Final Cut Pro and imported as HDV, I am working with a 1080i60 timeline. I exported as MP4, 5000kbps, 1280x720. I don't think that MP4 allows for de-interlacing, so I don't it is that. I know that I didn't consciously do any 30p stuff and the timeline is still in 60i and I don't think my settings are wrong in FCP (though there is a chance). As far as the shutter speed, I honestly don't know, but I think I kept it at 1/60. Thanks for your help!
-Steve

Andrew Kufahl
July 22nd, 2008, 08:54 AM
Steve,

I really do believe this is not an "A1" issue... it really seems to be a render output issue. You may therefore want to consider posting your question in a different section of these forums for [possibly] more specific help (not that the help here isn't good... but you know what I mean).

Everything I'm seeing (and it appears others feel the same) is more indicative of progressive. With interlacing, you'd normally see smoother motion (not ghosting), and you'd see interlacing lines (fields). I tried to trick Sony Vegas into rendering an interlaced MP4 file that Vegas would re-recognize as progressive, and I just can't do it. That leads me to believe that Vegas isn't lying when it says your footage is progressive.

I'm not an FCP user (never used it), so I personally can't give you too much direction on your render settings unless you post some screen shots or something. Which is why my recommendation is/was to post your issue in an area for FCP (maybe in "Non-Linear Editing on the Mac").

We'll do our best to help you, so please don't think I'm trying to "run you out of town".

Andrew

Garrett Low
July 22nd, 2008, 09:46 AM
Hi Steve,

I'm not a FCP user but you might check your field order for the interlace. HDV should be upper filed first. I've had it backwards before and come up with something similar.

Bill Thesken
July 22nd, 2008, 03:49 PM
Hey Thanks for your help:
Some more info: I am using Final Cut Pro and imported as HDV, I am working with a 1080i60 timeline. I exported as MP4, 5000kbps, 1280x720. I don't think that MP4 allows for de-interlacing, so I don't it is that. I know that I didn't consciously do any 30p stuff and the timeline is still in 60i and I don't think my settings are wrong in FCP (though there is a chance). As far as the shutter speed, I honestly don't know, but I think I kept it at 1/60. Thanks for your help!
-Steve

Could it be the shutter speed needs to be increased for the quick motions?

Steve Lewis
July 22nd, 2008, 04:55 PM
Thanks for the suggestions,
I started a thread on the mac section:
http://dvinfo.net/conf/showthread.php?p=910688#post910688

-Steve

Bill Busby
July 22nd, 2008, 06:49 PM
To the eye, this doesn't seem to be 60i. That could be the problem. This much ghosting is not normal, even for videocamera's.

To my eye, most anything on Vimeo looks to be a different frame rate than intended. It's always got the jerks goin' on. In my opinion Vimeo is one of the worst for showcasing & even more so for trying to show a problematic piece.

I used the download link for the file & just opened it & to me it looks purely like an interlacing issue stepping through frame by frame in QT.

Steve Lewis
July 22nd, 2008, 07:47 PM
I used the download link for the file & just opened it & to me it looks purely like an interlacing issue stepping through frame by frame in QT.

So, is that normal for MP4 files (which can't be de-interlaced)?
-Steve

Bill Busby
July 22nd, 2008, 08:03 PM
I wouldn't know Steve. I've never had the need for Mp4's. They just don't fit into my workflow. Maybe you could try deinterlacing in your NLE before exporting to an mp4? Or maybe there's something else altogether wrong & it just appears to be an interlacing issue I'm seeing. Hopefully someone else can chime in here that may be of help.