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March 13th, 2009, 05:02 PM | #1 |
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Anyone know what this image is suffering from?
There is horizontal banding in this video in spots.
I shot it with my EX1 at HQ 1920 x 1080 /60i and exported it to Raw DV (4:3 cropped) using Clip Browser. It is to be used in a 4:3 NTSC DV project 720 x 480 along with footage from a VX2000. Several spots have horizontal lines like the orange bedspread in this screenshot from the timeline in Vegas 4: http://i2.photobucket.com/albums/y40...ech/Image1.png I tried Avi and several other conversion methods and this is the best I could get it to look. After some conversions I tried the problem looked really pronounced. Anyone know what is it from and what can I do about it? John |
March 14th, 2009, 02:06 AM | #2 |
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Maybe my eyes have finally given up, but I can't see any horizontal lines in your jpeg. Perhaps they show up on a movie clip, if so then I would think it is the dreaded rolling shutter effect. This may be due to the stage lights being out of phase with your camera, try using 50mhz or 60mhz next time. (Page 66 of your Operating Instructions book)
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March 14th, 2009, 03:46 AM | #3 |
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Are the lines just to the right of the girls left arm ?
The lines there look like interlaced jaggies. Paul.
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March 14th, 2009, 04:13 AM | #4 |
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I see what you are talking about. It's a 1/2" horizontal orange/purple/black band midway between her left elbow and the purple furniture. I had to blow it up to see it at first. The artifact looks like its from another part of the frame (from her costume) but it doesn't match the current frame so it could be from a prior frame that did not get updated. It reminds me of the effect of dirty/misaligned heads. Do you see it when you play the footage from the camera on a monitor and bypass your NLE?
BTW, is that from Rogers and Hammerstein's Cinderella? |
March 14th, 2009, 05:20 AM | #5 |
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I had to enlarge the picture to 500% to see the lines. These are artifacts due to the downconversion of HD footage to SD. Do a search on this forum for downconverting techniques.
These only seem to appear on the red blanket (top edge) it looks like your reds are oversaturated, try reducing them in your Profile settings. I also notice your lens seems to have a lot of Chromatic abberations, maybe the colours are not registering correctly.
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March 14th, 2009, 06:18 AM | #6 | |
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Quote:
Someone else suggested that they are from interlacing. I read every post in the archives that I could find and it seems that downconversion is the biggest problem with these cameras and the most often asked question. I couldn't find a consensus. Any suggestions I may have missed regarding converting to 4:3 interlaced from HQ 1080/60i? In terms of "a lot of Chromatic abberations", that scares me. Can you describe them further? It sounds like the camera may need to go in for servicing and I need to be able to describe the problem in a little more detail to them. Do the others see this as well? Do a lot of you shoot stage productions? Thanks for the responses. Truly appreciated. John |
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March 14th, 2009, 06:31 AM | #7 | |
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Quote:
The oversaturated red will show up as a "bleeding", you may have noticed this on some poorly set up TV sets, or if you use an out of gamut red on a text caption. Downconverting footage from the EX3 has also been a headache for me. At present I am using ClipBrowser to output to an AVI (720 x480) and then bringing it in on a NTSC timeline (my project is in NTSC, normally I would use PAL). This has produced very acceptable results, although not as good as I had hoped for from the EX3. I will continue to experiment after I have completed this DVD project. The Chromatic aberations shows up as a green and purple edge to the edges of objects in your footage. Look at the bottom edge of the bar that runs accross the girls dress. or go to the left edge of the frame and see the book - object edges. Given that this is an elargement from a section, I wouldn't worry too much about this.
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March 14th, 2009, 06:58 AM | #8 |
When delivery is expected to be 720x480 (DV), it is always reommended you shoot 720p. Downconverting from 1080 generally results in these horizontal lines/twitter. This won't help you now, but, may be something to remember in the future.
Last edited by Bill Ravens; March 14th, 2009 at 07:33 AM. |
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March 14th, 2009, 07:11 AM | #9 | |
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Quote:
If I shoot in 720p what should I do about putting progressive footage on a timeline with interlaced footage. What do you do? John |
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March 14th, 2009, 07:33 AM | #10 |
Tuff question, John. I avoid shooting interlaced. If in a pinch, my only option would be to deinterlace before mixing. The best way to do this would be with VirtualDub and Donald Graft's deinterlace filter, IMHO.
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March 14th, 2009, 07:37 AM | #11 |
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Shoot 720 60p it is beautiful, and easily converted to 525 60i or 525 30p, or even 24p.
If you shoot 30p it will work well in a 60i timeline just interpret as i. I use Macs, mostly M100 but also FCP. I have never had a problem down-converting in software. I can give more specific details if you need them, but my experience is only on Macs. |
March 14th, 2009, 07:38 AM | #12 | |
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If I shoot another musical with only the EX1 I think I will absolutely take your advice and shoot it in 720p. John |
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March 14th, 2009, 09:05 AM | #13 |
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The only 'banding' that I can see is due to DV style colour sampling issues. That's simply how DV handles colours such as red and blue and the main reason that 4:2:2 colour is preferred over 4:2:0 and 4:1:1.
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March 14th, 2009, 09:53 AM | #14 |
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Where does this image come from? If it's the QuickTime Player have you checked the high-quality box in presentation settings? If it's a screen grab from FCP's canvas, don't sweat it that's just a proxy.
Noah |
March 14th, 2009, 02:09 PM | #15 | |
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Thanks Noah. John |
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