Recently I had the opportunity to calibrate and evaluate the new LG 50PK550 plasma at Cleveland Plasma.
The PK550 is very slim, and that combined with the narrow border give it a sleek, modern appearance. The screen, though highly reflective, seemed to stay fairly dark under high lighting conditions.
Though the PK550 lacks the THX mode of some of LGs other models, the ISF Expert modes offer a good mode to build upon. There are two ISF picture memories available, and they can be tuned to have a separate day and night mode for each input. In addition, they can be locked if you decide to get the unit professionally calibrated and want to make sure nobody makes unwelcome changes to your settings. Even before calibration (attachment 1), the results in ISF mode were closer to accurate than I normally see. However, the negative red in the absolute luminance graph and skewed magenta seen on the CIE graph suggests the uncalibrated ISF preset will have a similar color tone to the THX modes of early production Panasonic V10 and G10 plasmas, before their THX mode was fixed. These measured errors lead to a yellowish antique cast and can rob skin tones of their natural color and ruddiness. The PK550 often automatically dims the black level when it senses a few seconds of no picture content.
Fortunately, the PK550 has one of the best, most extensive advanced calibration menus available. Some of the nice touches include color isolation controls, which allow more accurate color adjustments than the filters included with test DVDs, a partial CMS adjustment, and the choice of either a conventional 2 point or a 20 point white balance and gamma adjustment.
The 20 point adjustment is very detailed, but is extremely difficult even for a seasoned calibrator to work with. For instance, the brightness of the menu changes the reading slightly, and some pattern generators and test DVDs do not have the required 5% small window patterns. Also, the PK550s non defeatable burn in protection dims the output if the image size stays the same for too long (no matter if the patterns brightness is changed), meaning you must change the size of the test pattern frequently and then go back to the windows you are working with. Though I was thankful to have it, the 20 point adjustment is a great example of too much of a good thing.
After much more work than required on an average plasma, the results were outstanding! The PK550s CMS adjustment, even though it was not as thorough as that on some other brands, allowed the colors to be extremely accurate. The higher measured error of the blue primary is not subjectively important in my experience. Light output with a small 100% white window measured 50 fL, and the pre-dimmed black level measured around .0132 fL. ASI contrast measured a very good 2000:1. Contrast measurements were performed with my profiled Milori Trichromat-1 meter, which is very stable and consistent with dark measurements. The light output and contrast measurements are both significantly improved over those of the LG 60PS60 plasma I reviewed last year, and mean the PK550s picture should have excellent pop and impact. The PK550 handles RGB or YCbCr colorspace properly via the HDMI input, and resolution is strong or perfect at all HD resolutions. I could find no pumping or stability problems.
After calibration, I turned off the lights and put in some very familiar 1080P/24 Blu Ray demo material. The first scene I looked at was the DVE HD basics test disc restaurant scene. I noticed right away that the pans were handled very well; they were noticeably smoother than on most other plasmas, with no judder, but not to the point of the dreaded soap opera look that plagues many LCDs. The panning and motion reminded me of the 96Hz mode on a Panasonic V10, which is a strong compliment. As the carrots and food appeared, I couldnt help but notice the colors; simultaneous vibrancy and naturalness is a rare combination, but the PK550 pulled it off in abundance. Shadow detail was superb; dark images were not washed out, but neither were dark images sunk down into a black blob. Thanks to the long hours spent fine tuning the 20 point adjustment, very dark images were properly neutral in color tone and were shown in the perfect balance between being easy to see and being dark/contrasty. The image had a strong sense of depth and dimensionality. The flesh tones were surprisingly rich but also quite natural; people didnt look sickly or too sunburnt. I expected very good pop and vibrancy due to the good measured light output, contrast, and gamma; and the PK550 even exceeded my high expectations in that regard by a bit. While still behind that of the best local dimming LCDs or the discontinued Pioneer Elite Kuros, I cant imagine the PK550 disappointing any level headed videophile in that regard.
There was a Panasonic 50G25 I had just calibrated sitting right next to the PK550. I just couldnt let the opportunity for a comparison slip by.
The thing that jumped out at me first is that the PK550 picks up much more glare than the G25. The G25 is probably the best plasma I have ever seen in that regard. With both sets turned off, the PK550s screen might have been a tiny bit darker with the lights on; but the reflections were much more distracting. The slim PK550 seems to run hotter than the thicker G25, which seems to produce surprisingly little heat. With both sets on but with a black 0% input, the G25 subjectively has slightly darker blacks, and its blacks were more neutral in color than the PK550s slightly greenish glow. The PK550 seemed to be more susceptible to image retention than the G25.
The PK550 has much smoother pans; the G25s 48Hz mode has too much flicker in my opinion, so I never use it. That gave the PK550 the advantage in handling 1080P/24 Blu Ray motion. The PK550 had bolder colors than the G25, and had a harder edged look with more pop. The G25 looked less contrasty and a bit on the washed out side of neutral in comparison. The G25 had more visible shadow detail, but it was a bit too visible to be truly accurate. The G25 had a slightly greener tinge and paler look to fleshtones. If you are the type of videophile who routinely turns down the color saturation to make various sources more palatable, then the G25s presentation would appeal more to you. On the other hand, lovers of rich and vibrant color tones would be more attracted to the PK550s picture.
Because of the G25s highly visible shadow detail, slightly higher light output capability, and superb resistance to reflections, I feel it would be an excellent choice for a brighter room. However, the PK550 has a more exciting and accurate image and would be a superb choice for a more light controlled environment.
While making this comparison, I was struck (and a little dismayed) by how much my impressions paralleled what I saw when I compared the Panasonic G25 to the Panasonic S2, but in this case the G25s role was reversed because of the characteristics of the set it was compared to.
I am very impressed with the overall accuracy and superb picture quality of the PK550. It shows a significant step up in performance from last years PS60, and in my opinion it even merits a good portion of the giant-slayer status that I give LGs bang for the buck leading LH90.
LG 50PK550 before ISF.pdf 149.740234375k . file
LG 50PK550 after ISF.pdf 139.1875k . file