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Old June 29th, 2004, 07:03 PM   #31
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Pondering this some more.... Just looked at my cameras and I think I need to re-shoot those tests one more time (arrgh) because the custom presets were clearly influencing the results. On the last test:

VX-2000
-----------
COLOR LVL = 0
SHARPNESS = -2
WB SHIFT = -4


PDX-10
---------
COLOR LVL = -1
SHARPNESS = -3
WB SHIFT = 0

This explains why the VX-2000 wouldn't white balance (duh!). I'm going to reset the defaults on all these (0). I imagine this will give an image that looks sharper but with stronger white outlines adjacent to the black lines. I don't like the overall feeling of the default sharpness for most things, but maybe it is more appropriate for bringing out detail in wide shots? To be continued...
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Old June 29th, 2004, 09:02 PM   #32
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Please do. We all adore you for the effort you put into it. Don't forget the AE point though. I just can't believe all that noise, and hope that underexposure is part of the reason :-(
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Old June 29th, 2004, 09:58 PM   #33
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Just finished shooting all my tests but I won't get a chance to edit and post until tomorrow, but verrry interesting :

I think these images will look a lot better. I reset all the custom presets to their defaults.

Used the waveform monitor in BTV pro to confirm exposure and focus. What a cool shareware program... I didn't even know it HAD a waveform monitor!

Tom is absolutely right in his frequent comparisons of low light capabilities of these cameras. I used halogen lights indoors with better control this time. The VX-2000 shot at f6.8 0dB while the PDX-10 was f2.8 0dB (according to its data code). That's 2.5 f-stops. Actually, based on the waveforms it's probably more like 2.25 f-stops or something, but the iris doesn't move in clicks that small.

Now this is really interesting: The PDX-10 showed my 16"x12" chart almost exactly full frame. But the VX-2000 showed a white border left and right when the chart filled the frame vertically! That must means the CCD proportions are not correct... when you film with the VX-2000 everything will look a little too tall and skinny! When I get the images into photoshop I can see how many pixels are involved, but it seems significant and is very noticeable. I have never seen any mention of this before. I double and triple checked this to confirm, and used the same tripod without moving it on both cameras. I lined it up vertically and horizontally on the chart as best I could.

I also shot a still photo with the PDX-10. Wow, 4:3 video really discards a huge portion of the CCD. That 690,000 pixels mentioned elsewhere sounds about right.

I re-shot my year-and-a-half old 16:9 tests also since I feel a lot better about exposure and focus on these new tests; I will be sure to export them as high quality JPEG's this time.

I also shot a still JPEG of the chart with my Nikon 5700 and will size that down to 720x480 for comparison. I think it might be better to use this in the tests instead of the raw chart JPEG since the contrast scale on the hardcopy looks different, but we'll see.

Give me a little time and I'll put a whole lot of stuff online, including all the raw images...

It would probably make sense to start separate threads in the appropriate camera forums to discuss these specifics, and I'll followup here with results that relate to the original "wide shot resolution" issue.
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Old June 29th, 2004, 10:34 PM   #34
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Way to go, Boyd! We will be eagerly waiting and Thank You for the work.
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Old July 1st, 2004, 09:14 AM   #35
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After recently shooting extensively with my first DV camera (the DVX100,) I can definitely see how the camera does a better job with close up shots then it does with wide shots. On wide shots everything seems….well…busy…almost as if the focus is soft, but it’s not really the focus. I simply think it’s the limited resolution of SD that is to blame. If I have to use the DVX100 on my feature then I will stick with medium and close up shots as much as possible.
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Old July 1st, 2004, 01:50 PM   #36
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Jim: Yeah, with the small resolution of SD, those wide landscape shots don't look that crisp and detailed. However, there are some ways around it. I have done a test before with a scanned 35mm picture from our Yellowstone vacation. The video (and at that time I was using a 1-chipper Sony TRV-140 Digital8.) didn't look that great on the far off shots, so I took the 35mm pic of the area, scanned it, added a bit of noise/grain to the footage, and put it in w/ the video footage. It looked acceptable to me. Although it was downsampled to 720x480, it looked way better than the video shots of the same area.

You can really go far and do some careful compositing with foreground atmospheric elements w/ motion layered over it, swaying trees, etc, etc... Also, environmental projection mapping would work if you want some camera motion in the shot.

Yeah, that is a lot of work but it may be worth it if you want a high quality shot.

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Old July 1st, 2004, 02:04 PM   #37
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The results are in

Here's my first attempt at organizing all the test shots I did the other day: http://www.greenmist.com/dv/res

I've tried to include all the tech notes on the webpage itself. The basic format shows 300% enlargements of a small section of the chart for quick comparison. Click on any of these to see the full frame as captured. These frames have not been altered in any way, other than exporting as high quality JPEG's from Final Cut Pro.

What I learned:

(1) The original JPEG file is still by far the cleanest image. The dv-compressed version does show some mosquito noise now however, not quite sure why this is more evident than it was in my earlier test.

(2) When I photographed the chart with my Nikon 5700 and down sampled to 720x480 it also yielded a very clean image with just a slight amount of noise. DV-compressing this image starts getting a bit more ragged, but still far cleaner than either the PDX-10 or VX-2000. Notice how the color and contrast shift due to the limited DV colorspace.

(3) The PDX-10 still is interesting to me. It shows better resolution than the camera in DV mode, but is still pretty noisy (sorry Ignacio ;-) What surpised me was that when I DV-compressed this image it changed very little.

(4) For 4:3 video the VX-2000 clearly beats the PDX-10, but not by a lot. However look at the improved vertical and horizontal resolution and somewhat lower noise level.

(5) Good example of the "warm image" that the Sony cameras are known for. In photo mode the PDX-10 image looks pretty neutral, but switching to video mode produces a pinkish cast. Both examples were manually white balanced. The video image also appears lighter as has been observed elsewhere.

(6) When it comes to 16:9, all those extra pixels on the PDX-10 make a huge difference. No contest here. The DV compression seems especially unkind to the VX-2000 in this example which looks pretty much like a big blob with less than 200 lines vertical resolution.

(7) I repeated the test from http://www.techshop.net/PDX-10/ to divine just how the PDX-10 samples video in the different modes and arrived at similar results, give or take a few pixels.

(8) Probably the most useful thing I learned in this excercise was that you can significantly improve the quality of your DV images if you look at a waveform monitor and adjust exposure and focus accordingly. These new tests are much cleaner than my first attempt.

Conclusions? Well the original question was "why do DV wide shots look so bad?" I only tested two cameras, but from what I saw it seems the answer lies in the cameras themselves. For whatever reason, they don't seem optimized to handle fine image detail. The DV codec itself introduces some artifacts, but nothing nearly as severe as the noisy grain I saw when enlarging framegrabs.
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Old July 1st, 2004, 03:46 PM   #38
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Thanks Boyd for the very interesting pictures, together with the complete picture descriptions. I believe they cover the matter very well. I posted some time ago on the VX2000 uprez issue: a better solution is to shoot in 4:3 and let yr display scaler do the uprez...a significant difference! Not only the difficulties with uprezzing interlaced pics are then gone ( because they first deinterlace before uprezzing) but also because they can uprez to a higher vertical pixelcount than the 525 NTSC lines.
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Old July 1st, 2004, 08:03 PM   #39
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Great work Boyd. Thank You for clearing up the noise issue, so to speak :-)
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Old July 2nd, 2004, 06:37 PM   #40
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Boyd, in looking at your test pics of the 4:3 from the PDX10, was there any kind of edge enhancement on ?
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Old July 2nd, 2004, 07:36 PM   #41
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That would be the sharpness setting on the PDX-10. I put it, and all the other custom presets, in the default position by performing a reset. The default is in the middle of the scale. Minus 3 clicks would turn it to the minimum. The VX-2000 was set the same, however even with matching settings less edge enhancement is visible there.
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Old July 3rd, 2004, 03:14 AM   #42
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Some picture contents (leafs, rocks...) "look" sharper when there is some edge enhancement. During standard shopping demo's an
attracive element for many people... and smart sales people.
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Old July 3rd, 2004, 07:55 AM   #43
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Funny you should mention that Andre.... yesterday evening I took my cameras out back and filmed a few seconds at each of the sharpness settings... in a scene with rocks and leaves!

Results to follow.
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Old July 3rd, 2004, 11:40 AM   #44
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Boyd, it was quite a long swim for observing you shooting...But back to reality...what looks awfull when applying too much(and thick) linear edge enhancement are human faces at quite some distance, like shooting groups of people.
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Old July 5th, 2004, 04:15 PM   #45
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For your consideration, a few more tests inspired by this topic:

http://www.greenmist.com/dv/garden Here I photographed an outdoor scene that has a lot of texture and fine detail using my still and video cameras. As I did with the resolution charts, I created a reference image by shooting a 2560x1920 high quality JPEG with the Nikon 5700 which I downsampled to 720x480. Quite a bit of detail is apparent here. Once again, I then compressed this JPEG with the DV coded, and the results may surprise you; it is very hard to tell any difference. I repeated this test several times, and actually compressed it into a new Quicktime DV movie which I used for my frame grab to insure that it really was DV compressed.

This image looks considerably better than either of the video camera images. So yet again I must conclude that the DV codec gets unfairly blamed for creating blocky images with lots of artifacts. I think that this test, and the resolution chart tests I shot before, support the thesis that the real culprit is our (relatively) cheap DV cameras! I would be interested to see any other tests that lead to different conclusions. But at least I now understand why the high quality broadcast cameras cost so much more than the small chip prosumer cameras we all know and love :-)

And once again, to put this all in perspective, I am looking at a small section of the image that's been magnified. The overall video frames look pretty good by themselves.

You will also find a variety of other new tests here that I've just completed, including the effect of the sharpness custom preset: http://www.greenmist.com/dv. Enough testing for now... phew... time to get outside and enjoy what's left of this beautiful holiday weekend!
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