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Old January 17th, 2008, 06:08 PM   #31
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Quote:
Originally Posted by Adam Letch View Post
in your TrueColour, or any calibration? As I believe the 50/60p is a 3:1:1 compression.
Adam, to add a color cast would defeat the whole purpose of TrueColor and would make it a misnomer. Please read the description about it on my website, http://www.paolociccone.com , the stated goal of TC is to give you the closest way to record neutral images with your camera. On my cameras, with a calibrated chart, with controlled light, TC provides neutral color.
Please double check the parameters in your camera and the white balance. If a color cast is still present it means that the color matrix of your camera is different from mine, something that is pretty common. That's why it's advisable to calibrate your camera with your own chart. The articles that I published on my website can help you perform that task.

BTW, with HDV you have 4:2:0 compression, regardless the frame rate.

Hope this helps
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Old January 17th, 2008, 07:40 PM   #32
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Oh no don't get me wrong Paolo

your TC is legendary stuff, I know that the intent is to add no colour cast, I've been using it on the HD251 since June 07, I just couldn't figure out how this colour cast had come into my work, the only thing I could think of was that I never shot in 720 50p before, I wondered whether it was possible that the colour matrix changes, and I vaguely remembered somewhere on this forum when the camera first came out, said that it used a 4:1:1 compression to be able to fit all the information in the same bandwidth.
I've seen it in my DV stuff now as well which is why I wondered that might be the case.
I'd love to be able to do my own matrix, but I've only got a little DSC camette chart which I would imagine isn't no where near enough to do the job. The only other thing I could think of is my tiffen polarizer has reacted to a cleaning agent or something and adding a colour cast. I know, I'm clutching at straws.

But anyways onward and upward...

ps : anybody other than me find that the 50p has more artifacting and noise compared to 25p?

Thanks
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Old January 17th, 2008, 08:07 PM   #33
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Adam, like with many things, "debugging" something like this is usually done with a process of elimination. Start with the "naked" camera, no filters on the lens, no ND, check the shutter (1/100 in this case), check the white balance, lights etc. Remove all elements one by one. The camera doesn't change compression because of frame rate. 4:1:1 is the DV compression. When the camera is set to record in DV format it does use 4:1:1 but that's expected, that is part of how SD DV is encoded on tape. Any of the HD modes use 4:2:0. The only difference is that when the HD200/250 records at 60p it uses a long GOP. 15 frames instead of 6. The color space and the color encoding remain the same.

Good luck.
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Old January 17th, 2008, 09:25 PM   #34
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Thanks Paolo

I knew there was some difference between the 50/60p and 24/25p, and the GOP was it then. Thanks as always for you prompt replies. I hope you current ventures are going well.

Regards

Adam
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Old January 19th, 2008, 01:06 PM   #35
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who-hoo!

no gloating here Paulo, ;^)
but be aware that although DVNTSC is 4:1:1, DV PAL IS 4:2:0.
4:2:0 is better for progressive material. Here's a ref:
http://www.adamwilt.com/DV-FAQ-tech.html#colorSampling
more than most of us really need to know about this...

In case I've injured your pride, here are some props: The testing routine is simply the best approach, even though it can take a lot of time. The lessons stick and apply to new situations much better. Just look at Eric taking this approach and trumping all us old-timers.

Makes me guilty here posting test videos online just for my whimsical queries.
Yes, the 300mm has minimal breathing issues for real work. The limited DOF and blooming from blur makes it hard to track - BUT, in the 2nd clip, I can still see the size of the rear view wing mirror change noticeably. It's cropped when in focus, and smaller in frame at the long focus at the start.
Prime lenses are generally much less subject to the problem. The 80-200 I suspect will be more noticeable. But hey - this is such quibbly (sp?) stuff. Good to be aware of, but even the significant breathing of the standard zoom is rarely a distraction to me.
Ah yes, the bokeh. A rich, luxuriant spread, with a peachy texture, typical of the California coastal regions. 8.6 points. Highly recommended. Ready for immediate consumption.
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Old January 19th, 2008, 01:27 PM   #36
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I'm such a chump. SO used to the 16X breathing somewhat like I did the first time I saw my wife - I considered the 300 breathless. That thing basically zooms when you focus.. I see what you're saying though, the mirror does distort. I promise I'll test the 80-200 today. I've been neck deep in a new project that's really got me consumed.
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Old January 19th, 2008, 01:51 PM   #37
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Dude - don't test it for me! Take your time, and check for yourself when your using it for something else.
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Old January 19th, 2008, 01:58 PM   #38
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Sean, this is how I learn. And I need to learn.. Don't fret yourself. It's all in a day's (year's) work.
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