επειδη διαβαζω το avforums θα ηθελα να πω κατι
το τι κραξιμο εχει φαει η vt20 απ'τους χρηστες αυτου του forum ειναι κατι το ασυλληπτο και ανεπαναληπτο ειδικα για τηλεοραση τετοιας κατηγοριας τιμης αλλα και γενικοτερα σαν τηλεοραση εγω προσωπικα δεν θυμαμαι αλλη να εχει φαει τετοιο μαυρισμα απο χρηστες
μιλαμε για την απολυτη παρανοια σε σημειο απιστευτης εμμονης με 99% αρνητικα ξανα και ξανα σχολια
με αποθεωση το παραληρημα ενος που το παιζει ο ξερολας του forum και εγραψε το συγκεκριμενο post...
"This post is to explain the findings of a visit to see and try to address some of the issues forum member Mysst (Chris) is having with his 50VT20. You have seen his postings. The brief was to see if calibration would help address some of them.
The findings are what they are and I’m not going to wrap anything up, just going to report to you how it is and what we found. What is going on is complex and I will attempt to explain in an easy non technical way.
On first inspection there were some very obvious things. 1, the amount of artefacts in the image. 2, nasty ringing round edges caused by edge enhancement. 3, posterization. 4, false contouring. 5 image retention.
Chris had set his VT20 using some results published from a net review. They were in the professional 2 setting. I thought the image looked green.
The signal source I used was a Sencore VP401 professional signal generator so all the patterns generated to take readings from the set are reference level. The meter used was a Klein K10, software is Calman V4 professional version.
Professional 1 setting was unused so I used this so we could easily see a before and after.
The set had 600 hours plus on it. First reading MLL, with 0IRE. This measured 0.012FL this is 0.004FL higher than the first VT20 I measured strait out of the box. BUT we should NOT conclude anything from this as it a different set, but to put it into prospective, one of my 3 year old Pio 4280 sets measured 0.011FL last night and my Pio 600a measured 0.002FL last night. Next measurement was light output with a 100IRE pattern. This measured 26.8FL and was too low for his room. So I ramped this up to 30.2FL when calibrating. Next I looked CIE colour points and my thoughts were correct, green was out, not slightly but miles out, hugely oversaturated, yellow too was out by some distance. Red too was out a little moving towards yellow, cyan too towards the green marker and Magenta was a little out towards red. Only blue was more or less where it needed to be. This meant overall the white point was pushing towards green. Greyscale showed at 80IRE all 3 primary colours were high and all at differing levels, at 20IRE they were all low and again all at differing levels but this time they were low, all signs of an incorrect gamma curve. I corrected the colour mix getting the primaries to line up at 80IRE but this sent 20IRE further out and lower, so I changed the gamma preset from 2.2 to 2.4 again could not correct this properly (remember this is also fighting with the fact that the main part of the ISF menu keeps covering the test pattern, not only that you have to keep moving the meter around because each sub setting appears at differing positions from the main menu and this is an absolute time consuming pain is the ass!)
I won’t go into the detail of how to try and change the gamma curve but involves shifting the 0 centre starting points of the high and low gain presets to differing equal start points IE highs to -3 and lows to +3. This helped but caused issues at mid IRE points so the only solution is compromise. I corrected the CIE gamut points by adjusting the saturation of the primary colours. Managed to get all the primary points correct, but there are no secondary adjustments. However the magenta and cyan fell into place with only yellow pushing slightly towards red. This brought the white point into line. Then checked black and white luminance levels, set up saturation completely defeated any edge enhancement (sharpness completely to the left and all other enhancement settings off, before going back to check greyscale and gamut points for a final time and making some minor changes decided that what I now had was the best that could be achieved.
Putting Sky back on and looking at the cricket, and golf straight away skin tones, whites and grass all looked substantially better. Colour had had more intensity while skin tones were in check. So the calibration (2 hours) had certainly improved colour accuracy.
That’s the good news, sadly the rest is not.
Posterization, it still there but it moves to different areas of the image. Posterization can be described as a sort of rippling effect in colour, you see it in a fade. Freeze the end of advert with a white back ground and then change to the different picture presets. As the picture re appears you will see this ripple effect, but as each preset has differing characteristics the ripple “settle points” end up at different places on the final static image. It’s hard to explain. But when the picture is moving these ripples once you see and understand will be a distraction.
False contouring, look at the still image below, this is a perfect example, the texture of the face is lost, the set cannot differentiate the subtle skin tones that are needed to produce a detailed image, and so it guesses and gets it wrong so you see these large areas of mush instead of detail. And when people talk about shadow detail, sorry but being able to see his hair and his shoulder is NOT shadow detail that is skewed gamma that falsely raises brightness level. If I raised brightness higher THEN you see colour detail in his cheek, but that washes the image out and reduces contrast. Actual shadow detail colour gradations are not good.
NOW, the image was from Sky Movies HD, things are better from Blu Ray but if like me, the bulk of what you watch is broadcast TV, then the image above is what you get. A good set should be able to deal with whatever you throw at it. And SD broadcast is even worse. Lesser thought of competitor sets handle this better.
Image retention, the BBC logo was in the image for the whole time I was there and showed no sign of fading. Chris had had BBC news on for around an hour or so before I arrived. Nuff said.
Edge enhancement, it can’t be defeated properly leaving ALL broadcast images with ringing and blu ray images being over sharp and unnatural.
Motion tracking, having looked closely at this and looked at all the exampled to highlight the issues, this is IMHO what is happening. Quite simply, theses sets are trying to be all things to all men and is not able to differentiate the differing types of frame rates thrown at it. Film, 24p, video, Pal, NTSC HTPC, gaming, 3D all need different settings and the set is tripping up.
This is really hard to explain and break down but I will try. Below is not what is happening but it’s a simple theory to enable some understanding.
If you have been watching some film that needs 24p, let’s assume the TV had received a 24p flag (trigger). You finish watching the film and then put some football on, but the set receives no VIDEO flag, it’s still in 24p mode but it needs a 50Hz flag but does not get it, so it stays in 24p mode. Now it’s far more complex that this but its goes some way to explaining it. Where I think the main issue lies is that I actually don’t think the set has a native 50hz mode, I think it’s is 60Hz natively and it’s doing some sort of conversion, BADLY. This is why some people are seeing flicker!!!! 3D works properly because all the frame rates are in harmony, 120Hz that’s 2X60Hz, blue ray works properly 24px5 that’s 120Hz but 50 does not go into 60 or 120, does it?
Pioneer sets have manual adjustments so you can get things right, you also have a PC MODE, that works at 60Hz and if you feed SKY, Virgin, a UK DVD player into this mode. IT DOES WHAT THE VT20 and all the other Panny sets do, same flicker same judder!! 600HZ IFC is an over ride to try and deal (mask) this but we all know the side effects.
As stated the set is making these adjustments automatically, but because the sets native rate is 60Hz not 50 Hz and does not have a native 50 Hz mode, IMHO this is why the issues are present and sadly I don’t think its firmware fixable.
It’s fixable with 3rd party external processors but do you want to spend £2/3,000 pounds on one and then some £500 to have it configured. Good processing costs and its CAN’T be automated. Not only that add to it, like in the case of Chris here, that he is going through an amp first with certain things configured it throws things out even more.
To sum up, I don’t know what to say, this set is a showcase for technology, it’s like the iphone 4 or a Microsoft Small business server. It’s trying to do everything and gets the most basic things needed wrong. The iphone 4 is a superb technology showcase but is crap with making phone calls. A Small business server has everything a small business could want but struggles to allow basic control as it is pushing you to do what it wants, not what you want.
And then there is the VT20. Its 3D works better than any competitor, however watching it in the day time here at Chris’s while there was no flicker in the image, his beige walls were flickering like a mother and taking the glasses off it was easy for both of us to see this flicker of the glasses. This ficker made daytime viewing unwatchable. Static images are really sharp but the second there is any movement resolution falls away and integrity of the image breaks up making Pal 50 Hz broadcast TV hard to watch.
There you have it, calibration helps colour accuracy but sadly addresses nothing else. There is much more I could post but hope this gives an idea of what seems to be the reasons behind the motion issues."
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