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March 7th, 2007, 04:03 PM | #331 |
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That's exactly it. An SD television dispays 480 lines (essentially that's part of the specs of an NTSC SD television), and a letterboxed 16:9 image uses only 360 of those lines.
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March 7th, 2007, 11:17 PM | #332 |
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Wow, I never thought of that. Thanks for making this topic.
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March 8th, 2007, 12:35 AM | #333 |
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So I did a little test to try out this hypothesis.
I took video of a fan in my room with the FX1 and VX2000, in 16:9 SD on both. Then I captured both into Pinnacle 10 Plus. From there, I captured a 1 bit map from each clip. They are shown below as FX1.bmp and VX2k.bmp. The bit map image turned out to be 853 by 480. Then I took those images into Photoshop, created two new blank images at 640 by 480 to simulate SD TV resolution. I then copied the original photos and reduced them to fit into the 640x480, leaving bars at the top. I will let you be the judge of the images. My impression is that the reduction in resolution actually brings the VX2k image closer to the FX1 image. (I was hand holding each camera, and shot in auto, so there may be some shake issues there.) Check it out.
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March 8th, 2007, 03:26 AM | #334 |
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sorry but the difference stay the same for me, at original size or reduced.
...and VX looks much better. but the important thing is what YOU see, and if you are happy with the VX2000 picture, nobody should complain. From my point of view, SD can be as good as HD. I run everyday good DVD on my 1344x768 42" LCD TV (HDMI comnnection to player) and they look much better than everything i can get from my VX2000, or even the same as my FX1, but these are SD DVD. it is especially amazing on cartoon like "over the Hedge" or "Happy Feet" or "Shreck" were you can see every details of animals furs or every dot of skin texture. The only difference is that the original material is very high resolution. Last edited by Giroud Francois; March 8th, 2007 at 09:52 AM. |
March 8th, 2007, 09:38 AM | #335 |
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It looks like the FX1 image was sharpened more in-camera. Actual resolution isn't as different as the difference in sharpening can make it appear. Try sharpening the image from the VX (in photoshop) and I think you'll find they look a bit more similar.
There are other differences though. The color balance of the FX1 image looks cooler. There appears to be more noise in the VX image. Just my impressions, at a glance. |
March 8th, 2007, 09:43 AM | #336 |
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Sorry for "hammering" you Chris :-) Handholding is probably not the best way to show what the FX1 can do. I have done tests myself, and had them online for a long time but finally dumped it all to make room on my website. But they convinced me that 16:9 on the VX doesn't give the quality I need.
Comparing them on a regular TV probably isn't a good way to judge the difference, but I think Giroud makes a good point. If they work well in your application then who cares what all of us think? ;-) I think it's great that you took the time to do this and draw your own conclusions actually. Much too often people ask questions of strangers and base decisions on the response because they're just too lazy to do a little research on their own. But it you want to do another test, go outside and shoot some kind of landscape on a tripod with a lot of small objects, like distant trees or buildings. I think you will see a more pronounced difference between the VX and FX in this situation. Also, I'm not all that impressed with shooting in SD mode on my Z1. Pretty sure the difference would be more pronounced if you shot in HDV and downconverted either in-camera or with software. Couple things though: 1. It's 360 lines and not 380. 2. The VX and just about all SD cameras without true progressive mode do some form of field blending. This is necessary to prevent flickering edges on nearly horizontal surfaces and lines. Imagine a horizontal line which is only one pixel wide. It would be captured in the odd field but not the even field, and would therefore flash on and off with interlaced video. So even though 360/480 would appear to be a 25% loss of resolution, in reality it's probably not that severe since the VX doesn't really output 480 discreet lines in the first place. |
March 8th, 2007, 09:53 AM | #337 |
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hey chris, want to try something else while you're at it? do another screen cap with that "flash setting" on. i personally don't see a visible quality difference and that mode kinda replicates progressive(kinda) so why not give it a shot!
also, you already turned your sharpness down in the cams, right? |
March 8th, 2007, 10:02 AM | #338 |
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The downsampled Z1 HDV image should be a bit sharper than the VX, but if the downsampling is done in photoshop, the difference will appear to be greater, because the downsampled chroma resolution will be higher than with the 4:1:1 coming from the VX.
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March 8th, 2007, 11:32 AM | #339 |
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Everything was on auto on the cameras, including focus. FX1 was actually set to the PP1, which I have not modified from factory settings, I realized afterward, I used the fan housing because it had straight lines and curves. Should have mounted on tripod, but I did this on spur of moment more than anything just to see results, deciding to post them afterwards. I could have definitely been more scientific about it.
I do see a clear difference, in the full resolution video, comparing the two, and that is clear. My only point is that in the process of encoding to DVD mpeg, then having the DVD player scale to a standard 4:3 screen, the greater portion of that difference can disappear pretty quickly, and assuming that is your target, use of the 16:9 feature on the VX's and PD's may not be as detrimental as I was originally thinking. Boyd, I agree with your thoughts on the actually editing FX1 footage in HDV or Cineform intermediate, then down converting. I do that regularly. And I I'm experimenting with a self built 35mm adapter using that process too. I will try to do the landscape "test" in a day or too, also, because my curiosity is up on that one too. In the past with the VX2000, if I had wanted a leterbox 16:9 effect, I would use an in camera mask. So I will add that to the test too, just to see where that goes.
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March 8th, 2007, 11:35 AM | #340 | |
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Quote:
Lets see, a wedding this weekend, finish UWOL challenge, then fun experiments...
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March 8th, 2007, 11:38 AM | #341 |
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Well no argument there. When you letterbox 16:9 in 4:3 you only have 360 lines in the image area, so there isn't gonna be much if any difference. The expression "pearls before swine" comes to mind if you're using an FX1 for that application ;-)
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March 8th, 2007, 12:11 PM | #342 |
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Boyd:
While we are on the subject of FX1 and VX, lets say for some reason I want to shoot the two cameras in 4:3 for an SD gig. From what I can tell, the FX1 and z1 lops off the sides, relying on the pixel aspect ratio to give the full picture 4:3. But doesn't that actually reduce the actually pixels, and since it does, how does that effect resolution ?
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March 8th, 2007, 03:27 PM | #343 |
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IIRC, the sensor has 960 pixels but interpolates this to 1440 using pixel shifting. So I think there are enough pixels to get full resolution (especially as you say your target is 4:3 on consumer TV's) but it's more like shooting with a 1/4" chip camera since the sides of the 16:9 native CCD's aren't being used in 4:3 mode.
My totally unscientific gut reaction is that 4:3 video from my VX-2000 looks better than 4:3 from my Z1. Recently I looked at some 4:3 material I shot 5 years ago with the VX, and I was reminded just how nice an image that camera can create. |
March 8th, 2007, 07:15 PM | #344 |
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Okay, as Boyd suggested, I did the landscape test on the FX1 and VX 2K, both in SD, obviously. On the VX2k I also shot one in 4:3, using a mask I applied in memory mix mode.
The shots below are labeled and self explanatory. It looks like again, at better performance as Boyd indicated in FX1 16x9, especially at full DV resolution, with what I think is a decreasing the edge in the 640 by 480 resolution reduction. The shot with the matte applied gives pause, at it appears at least as good as the 16 by 9 VX2k mode shot. That confirms what I've seen earlier user indicate. Problem with it is if you mix that on a 16:9 time line, you have to stretch it to fill the frame, and I think you lose there. .....
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March 12th, 2007, 12:35 PM | #345 |
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I recently did a year-end wrap up reel mixing footage from VX2100, Canon XL1s, and a Sony A1U. The final project was 16X9, done in post. I have to say that shooting with the VX in 4:3 and then stretching it in post yields some NICE results. I was pretty surprised at how well the VX stacked up against in the other two cams.
my $.02
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