GS400 PAL not conform! at DVinfo.net

Andre De Clercq · April 27th, 2006, 02:51 AM

Did somebody ever verify the GS400 signal on a waveform monitor? The signal has the NTSC 7.5 IRE offset. This doesn't comply with the PAL (CCIR) standard. So this cam is unusable in a multicam session with other PAL camcorders. This faulty situation can also be verified in an NLE (e.g. Premiere ) which has a SW waveform monitor

Peter Jefferson · May 7th, 2006, 07:30 AM

LOL no offense dude, but ive religiously used GS400 and MX500 alongside DVX100s for mult cam shoots.. sure the colours slightly off, but its to be expected considering the variants in each camera.
Ive never had a problem matching colours in post... the only real differences is the saturation of red levels and white balancing in general..

I wouldnt panic too much about it.. NTSC has been running perfectly fine over the last 30-40 years ... what WOULD be interesting to know however would be whether its colour sampling is at 4:2:0 or 4:1:1 and i definately KNOW that premiere cant tell u this.. Another thing to note, is that premiere isnt always corect in teh way it "see's" things.. which is why ive ditched so many projects which were born on it..

Andre De Clercq · May 7th, 2006, 09:09 AM

Thanks Peter for your responce. Be shure, no panic...Of course, when I noticed this first in Premiere pro, I verified this with my Gould Advance oscilloscope and got exactly the same results. Also when compaired to my Sony VX2k and Sony TRV14 signals I get the difference in black level. For the same black (velvet) in a test pattern, the Sonys are at 0 IRE. the GS400 at 7 IRE. I agree , subjectively, when there is are no dark scenes in the footage (movie), the difference will not be noticed by most people. I would be happy if somebody could veryfy if he could get 0 IRE black out of a PAL GS400 even with closed lenscap, and gain at 0db.
On the good old NTSC I agree with the 7.5 IRE offset, even a 15 or 20 IRE standard would be (appart from losing some signal DR) perfectly OK. Only when signals with 20 IRE offset would have to be mixed with 0 IRE offset signals would be a problem.
On the sampling raster I don't think any camcorder manufacturer would fool such a fundamntal standard property. Of course Premiere can't tell you (like any other NLE can't) because it hasn't to measure this or to be adaptive to. It is being set by the project standard, NTSC4:1:1, Pal 4:2:0. If GS400 would keep 4:1:1 in Pal, Premiere with PAL setting would simply interpret as 4:2:0 resulting in a poor 4:1:0 signal with strong (mainly vertical) color leakage.

April 27th, 2006, 02:51 AM	#1
Andre De Clercq Major Player Join Date: Sep 2002 Location: Belgium Posts: 804	GS400 PAL not conform! Did somebody ever verify the GS400 signal on a waveform monitor? The signal has the NTSC 7.5 IRE offset. This doesn't comply with the PAL (CCIR) standard. So this cam is unusable in a multicam session with other PAL camcorders. This faulty situation can also be verified in an NLE (e.g. Premiere ) which has a SW waveform monitor

May 7th, 2006, 07:30 AM	#2
Peter Jefferson Inner Circle Join Date: Apr 2003 Location: Aus Posts: 3,884	LOL no offense dude, but ive religiously used GS400 and MX500 alongside DVX100s for mult cam shoots.. sure the colours slightly off, but its to be expected considering the variants in each camera. Ive never had a problem matching colours in post... the only real differences is the saturation of red levels and white balancing in general.. I wouldnt panic too much about it.. NTSC has been running perfectly fine over the last 30-40 years ... what WOULD be interesting to know however would be whether its colour sampling is at 4:2:0 or 4:1:1 and i definately KNOW that premiere cant tell u this.. Another thing to note, is that premiere isnt always corect in teh way it "see's" things.. which is why ive ditched so many projects which were born on it..

May 7th, 2006, 09:09 AM	#3
Andre De Clercq Major Player Join Date: Sep 2002 Location: Belgium Posts: 804	Thanks Peter for your responce. Be shure, no panic...Of course, when I noticed this first in Premiere pro, I verified this with my Gould Advance oscilloscope and got exactly the same results. Also when compaired to my Sony VX2k and Sony TRV14 signals I get the difference in black level. For the same black (velvet) in a test pattern, the Sonys are at 0 IRE. the GS400 at 7 IRE. I agree , subjectively, when there is are no dark scenes in the footage (movie), the difference will not be noticed by most people. I would be happy if somebody could veryfy if he could get 0 IRE black out of a PAL GS400 even with closed lenscap, and gain at 0db. On the good old NTSC I agree with the 7.5 IRE offset, even a 15 or 20 IRE standard would be (appart from losing some signal DR) perfectly OK. Only when signals with 20 IRE offset would have to be mixed with 0 IRE offset signals would be a problem. On the sampling raster I don't think any camcorder manufacturer would fool such a fundamntal standard property. Of course Premiere can't tell you (like any other NLE can't) because it hasn't to measure this or to be adaptive to. It is being set by the project standard, NTSC4:1:1, Pal 4:2:0. If GS400 would keep 4:1:1 in Pal, Premiere with PAL setting would simply interpret as 4:2:0 resulting in a poor 4:1:0 signal with strong (mainly vertical) color leakage.