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Panasonic HDX900


Lee Dashiell

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Hi,

 

i have one big problem, cromatic aberation, so it realy a maner to corect this in the camera.

 

Here it a frame, 300% zoom and contrast/luminace at max. in CS2.

 

The lens it HDcg Canon.

 

I realy apreciate your help.

 

Of corse more footage are at this link, but are CC http://www.flickr.com/search/?q=hdx900&w=all

 

Gabriel Bordas

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As far as I know Panasonic has only included CA compensation in their two newest 2/3" cameras, the HPX500 and HPX3000 (the compensation files are created by Panasonic for specific lenses). There is no CA-Compensation included in the HDX900.

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Hi Michael,

 

thank's, i now about CA in the HPX camera but it there a maner to manual do this. How it achived CA.

 

Panasonic programs the CA compensation for different lenses, and includes those compensations as files in the camera. It's not something that the user can perform, like lens shading.

 

As for color correction, I suppose it could be done to some extent, but it would be very labor intensive. CA seems to vary with aperture and focal length..

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  • 2 weeks later...
The chips are 720. It does an internal upconversion to 1080p, and downconversion to 1080i.

 

 

-- J.S.

Can you elaborate on this more I am not sure I fully understand what the camera is doing to get to 1080I How does it differ from say the Sony F-900 s 1080I

Edited by Scott Imler
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  • 1 month later...

We did our shoot a couple of months ago on the HDX-900, and the production has put some frame grabs on its website:

 

http://www.sugsproductions.com/LLC/Production_Stills.html

 

The pictures look a little too "video" for me, but I have no idea how they were grabbed, or how compressed they are. I did kind of miss the Varicam's "variable shutter." I like shooting w/ a 200 degree shutter, and we mimicked that effect by setting the shutter speed at 1/40 second, but this really seemed to rob me of a couple of stops of exposure. Also, this created a flicker problem w/ practical florescent lights running on a 60hz cycle. (I guess it's a problem I didn't bother to solve.) On the other hand, I have no problems w/ the camera's dynamic range. The actors face in the hot shaft of light, for instance, was way off the chart on the waveform, but w/ no ill effects.

 

Having the SD-out came in very handy when we did our two steadi-cam shots ... no need for a down-converter!

 

I have a bunch of other random thoughts ... but too random to sort out at the moment.

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Can you elaborate on this more I am not sure I fully understand what the camera is doing to get to 1080I How does it differ from say the Sony F-900 s 1080I

The camera is doing a lot of arithmetic. In fact, both cameras do some arithmetic to get 1080i. The Sony F-900 has 1920 x 1080 photosites on its chips, while the Panasonic has 1280 x 720.

 

Theoretically, the Sony could just hand you the numbers straight from the chips for 1080p purposes. I don't know for sure that they do, they might be doing some tweaking. To make 1080i, Sony has to give you two sets of 540 lines, the even ones and the odd ones. But to just pull them directly from the 1080p image doesn't quite work. They have to do some filtering to reduce the vertical resolution to about 65% of the full progressive resolution, or else you'd have massively hideous small area or interline flicker.

 

Panasonic has a bit more math to do, as they have to resample both horizontally and vertically. It's a bit more complex than just laying one grid over the other and taking percentages of the old pixels to make new ones. Usually these are multi-tap filters that use data from several adjacent pixels, with both positive and negative coefficients.

 

If you have access to Adobe Photoshop, re-size some test images using its Bicubic Interpolation -- that's pretty typical of how these conversion filters work.

 

 

 

 

-- J.S.

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  • 4 months later...
Thanks Darrin.

 

Sorry to get off tangent with your post.I have a couple HDX900 questions for the HX900 Guru. I would like to restore the camera to factory defaults and loose the loaded scene file settings. Is there a licky split menu choice? Also is there a detailed forum on the lens files, and how they relate to the different HD lenses available? Thank you for your time, Nick, contact@misterphoton.com

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