Originally Posted by 6bkt9
Just received a P50GT50 and have been watching it for 3 days after researching that this TV represented the best bang for the buck available.
Admittedly - I should have spent time in the shop watching it and comparing it to others, but the TV was setup in a brightly lit shop and not in a way I would have noticed. I also thought the research & ratings made it a safe purchase.
I'm seeing rainbows too - and any content from my virgin media box (@50Hz) I also see flickering as well when I'm not looking directly at the screen.
I love the blacks/contrast and colours in comparison to any LCD/LED I've seen but the TV is making me feel slightly dizzy watching it and is distracting - any fast movement or action on screen or my eyes looking from one part of the screen to another means I see rainbow flashes - much like I also see on a DLP projector display.
I used to own a Samsung plasma 50" 7 series plasma and didn't see this rainbox effect so I would not have expected it from the Panasonic especially one rated so highly.
I've only had it 3 days and now contemplating having to resell it 2nd hand and buying another TV.
Panasonic's spec sheet stating 2500Hz focused field drive etc seems like technical mumbo jumbo when the reality is, on poorer quality content, the set in general use is disappointing, to say the least - compared to its rivals.
Anyone else had this experience?
The thing I would stress to any purchaser of a TV is to definitely spend time (an hour or more) watching it in a shop on a variety of content - but lit properly like your home - to establish whether you can see any artifacts.
The other thing is perhaps the reviews are biased towards the top of end of content quality and would be better if they also focused on day to day use as well - I wish somewhere I had seen a caveat that if you are prone to seeing rainbows or flickering or wanted to watch a set top box with a 50hz signal, to look elsewhere.
You are dumping numerous complex topics into one post. Many of these have become independent discussions on there own.
From the 50 Hz VM box comment, I am guessing you are in the UK which runs video content at 50 Hz. I'm not very knowledgeable about non-US systems but from what I know, most of the effects you are describing are related to how TV's upscale and de-interlace 50-i SD content. Color trails and flickering have been criticized for years in the UK because of the way some TV's handle double scanning and frame interpolation. Different STB's contribute to the problem in how they process the raw signals.
Low refresh rate flicker can very noticeable below 55 Hz on average. If I set my GT50 to the 48 Hz rate (this is an option in the US for 24-p direct input) the flicker is very pronounced, at 60 Hz it can only be seen by a small percentage of people and only on bright areas in the image. I'm not sure what is available and compatible in the UK, but if you can find a secondary video processor to clean-up and rescale the output from the VM box before it goes into the GT50 you may get much better results. Here in the US, the PQ on the GT50 is excellent on HD content and good on SD content but some feel the SD content is not all that it should be. If the TV is actually running a 50 Hz mode, I'm not surprised it looks flickery. Check to see if you have any options for a 50i/100i mode and/or and interpolation/interlacing options.
The rainbows on single chip DLP's (in the US) were created for a completely different reason. Those sets used a spinning wheel that alternated the colors on the screen "in time" which averaged to "white" in theory. On fast motion pans the averaging time per frame could be too short to give a neutral color balance. Research done earlier by the US military on color perception showed the entire design would not work. Plasma displays create "white" by simultaneously displaying red, green, and blue pixels side by side in space rather than completely red, green, and blue images alternating in time. 3 Chip DLP's were much closer to plasma. The rainbow effects on those was related to de-interlacing the video signal to display it on fixed pixel "progressive" chip.
2500 Hz FFD is a technical topic but is very real. Keep in mind this has nearly nothing to do with refresh rate. Too many people seem to think this means 2500 Hz refresh rate; NO not even close. The field driver has a fixed time (the refresh rate) to generate plasma, excite the phosphors, let the phosphors emit, and let the phosphors decay to the next state needed. 2500 Hz refers to the rate each pixel can undergo this cycle. This high rate allows for the capability of multiple adjustments within each frame and finer grey scale control. Whether or not Panasonic can develop video processing software to take full advantage of the 2500 FFD hardware is a wait and see prospect. I love my GT50 but I can't say the 50 series video processing is taking full advantage of the 2500 FFD. Maybe next year the video processing will catch-up to the greater capabilities of the panel and display driver.
Hope things work out for you.