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Discussion Starter · #1 ·
As I've stated before, I'm interested in the JVC SX21 (maybe Feb. release) so have been holding off on the Infocus 7200, but two things bother me about the published specs on the SX21:


1. DVI not HDCP compliant

2. On spec sheets where it says "3:2 pulldown" it says "no".


Is this a Deal Killer??


TA
 

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Discussion Starter · #2 ·
I should mention I'm not a video tech-head, but I know during the telecine copy process the film 24-frame / video 30-frame is adjusted. If a video device is being fed "adjusted" 24/30 video anyway, why would said video device have to have 3:2 pulldown circuits?


TA
 

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Quote:
Originally posted by Timbelmont
I should mention I'm not a video tech-head, but I know during the telecine copy process the film 24-frame / video 30-frame is adjusted. If a video device is being fed "adjusted" 24/30 video anyway, why would said video device have to have 3:2 pulldown circuits?


TA
TA,


The problem comes during the de-interlace process.


Standard NTSC video is interlaced - that is it scans the odd numbered lines then the even numbered lines. For a projector,

we want to convert this to progressive video where the lines are scanned in numerical order.


The way the 24 fps film is adjusted to 30 fps video is by repeating fields. Lets say we have 4 frames; frame A, frame B,

frame C, and frame D.


Let Ao be the odd lines of A, and Ae be the even lines.


The telecine process or 3:2 pulldown does this:


Ao Ae Ao Be Bo Ce Co Ce Do De


You can see that for every 4 "fields" an extra field is thrown in; Ao and Ce in the above. That's how the adjustment

is made for the lower frame rate of film - 25% more information is created by repeating fields.


The problem comes if you have a dumb de-interlacer. Such an interlacer would take the first two fields Ao and Ae and

combine them into frame A. So far so good.


However, it would then combine Ao with Be. In other words, it would create a whole frame by combining the odd lines of

frame A with the even lines of frame B. These lines were never meant to be merged together - and can give strange

looking artifacts.


That's why the de-interlacer has to be aware of the 3:2 pulldown method for adjusting the 24 fps film rate to the

30 fps video rate.


Dr. Gregory Greenman

Physicist
 

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timbelmont


go to the special guest forum and read the posts from the president of Maxx, they will be selling the SX21
 

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missing features? 1920 x 1080 panels. The rest of the projector can support it, so why not?
 

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maybe this is why


"In reference to 1920 x 1080 as I stated we are working with three well funded engineering / manufacturing firms that are also banking on 1920 x 1080. I am in great hopes they will succeed. If so, we expect to have 1920 x 1080 for approx $ 15,000 retail. Unfortunately, thus far only JVC has brought to the table projectors that work. The other various LCOS units have been more than just poor – very noisy video, blacks that are blue and lacking even in that"
 
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