Iscan Pro and PAL confliction on Panasonic


uncle eric

Ok, finally got the Plasma install in my living room finished and very nice it looks to. Plasma is the Panasonic PW5.

Knowing that the Iscan Pro does a better job at de-interlacing than the panel, I installed one with all sources connected to it and outputing to the Plasma.

As you can imagine, images on NTSC are superb. Quality on many R1 pressings is something to behold. PAL is quite another story.

Sky together with R2 DVD both have the same problems. A slight tearing at the top of the image with a few blocky artifacts. Now it could be that the panel doesn't like the iscan. I'm still unsure.

I wrote to Silicon Image to try and get to the bottom of this and heres the reply from Ron at S.I.

The iScan is somewhat weaker in PAL film mode detection, but it should not behave like that.

Can you plug a computer CRT monitor into the output of the iScan and let me know what the
result is? On NTSC, the iScan outputs 480p which is 720x480, 60Hz, 31.5KHz horz scan rate.
For PAL, it is 576p which is 720x576, 50Hz, 31.25KHz horz scan rate. If the computer CRT
works OK on PAL , then the iScan is working OK and the plasma is probably somewhat par-
ticular about the timings it is getting in and doesn't like 576p.

The iscan is definately out puting the correct scan rates. So far so bad!!!!!

uncle eric

Hi Gordon,
I've have three PAL sources, Sky, a European Digital Sat system, and PAL dvd. All exhibit identical artifacts.

Using the same DVD player, NTSC is awsome.

I tried a Duece MC (thanks Henry) outputing the native res of the panel 852x480 with exactly the same results.

I used to have lots of hair up until last week :mad:


Standard Member

I remembered a discussion regarding problems with the Panasonic PW3 Plasma on a few months back. I think there was some mention of tearing and Iscan Pro etc., with some input from Panasonic themselves. Anyway, if you are interested the link is:

It was a member called Chip who mentioned the tearing. Not sure if it's the same Chip as we have on here but it might be.


Joe Fernand

Distinguished Member
AVForums Sponsor

I wonder if you are having a similar problem to r22flyer - (tearing when using one of Dr Johns boxes) - as Gordon's hunch proved the output levels from the sources are affecting or overloading the display or Dr Johns converter (John is on the case so maybe he can advise if he thinks its his box that is being overloaded).

I wonder if your iScan or display is suffering the same problem with PAL sources - we used to see this type of problem quite often when setting up video walls and the like on exhibition stands and event stages; you only had to slightly increase the output of our pattern and colour generators to start getting the top of the image tearing.


Gordon @ Convergent AV

Distinguished Member
AVForums Sponsor
Just thought I'd add that I now remember speaking with a colleague in another country who had the same issue when using anpther manufacturers line doubler with his first D5. Not sure if he resolved it.

Certainly worth trying tunring down contrast though to see what happens.


uncle eric

Thanks guys. I think the problem is iscan orientated. The humax satelite system is running straight through the iscan as is Sky digital and the DVD player. If I show the Panny (through the iscan) anything PAL its goes into one (even through the DVD player with R2 discs).
Use NTSC (R1), end of problem, superb to look at.
Though it looks like a sync/clamping problem I can't be sure. Whatever it is, I don't think the problem is with the panel or John Sims converter. I think its more iscan/pal/panasonic confliction. Or is it???


I use the iScan on PAL sources with a Fujitsu panel with no problems so it sounds like some sort of iScan/Panny conflict


Active Member
have you tried the Iscan in to a PC monitor? Do you get the tearing? If not, then it's from the Iscan to the screen. I've seen the Iscan working with PAL, and it does a very good job. But I really need more information, please email me.

I've been working with R22Flyer on the component converter issue. He's got a Pioneer DVD player that's outputing 1V for video lines, which should be 0.7V max. 43% more than it should be. With a larger input, you get a larger output. R22Flyer is going to loan me his DVD player (I don't have a Pioneer, only Panasonics), and I'll be able to investigate further.

All the best,

Dr John Sim.

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