Test af amerikansk G25. (Chad Billheimer!)

I recently had the opportunity to check out the new Panasonic G25 along with the S2 at Cleveland Plasma. I was impressed with Panasonic's models last year, after they got the THX color decoding issue fixed. I continue to hear rumors about Panasonic hiring Pioneer's techs and using Kuro technology, but for now, the V10 is doing a good job holding us over. Could the G25 either bring us one step closer to the mighty Kuro, or at least give equivalent performance to the V10 at a lower cost?

One thing I noticed right away, before even turning the G25 on, is that the screen looks nice and dark. The feature list proudly includes what Panasonic calls "infinite black", and I have to say it does an outstanding job staying black in bright rooms. Because it's so dark, it does a good job of muting reflections. It is still possible to see glare in the G25's screen in a bright room, but it's much less distracting than I normally expect from a plasma. When it's turned on, the G25's blacks are dark for a plasma, but definitely not infinite black. The G25 does not have the internal reflection that causes the odd "double image" look on the V10 when looking from off axis. While I always felt that effect was more of a curiosity than a serious issue on the V10, nevertheless it's good that the G25 seems to have been engineered without the optical gap that caused it in other models.

The G25 is THX certified, so instead of a cinema mode there is THX mode. THX mode's color gamut is, by design, much closer to the HDTV standard than the other modes (and most other TVs). With the exception of the previously mentioned THX issue that was resolved by Panasonic last year, I have been a big fan of THX modes in most displays because of the natural color and detail. However, light output has always been the limiting factor: THX modes have had intentionally limited light output, with the idea being that if you truly care about an accurate picture, you'll be watching it in a dark room. I usually end up calibrating THX as a night mode, and then using custom mode for brighter daytime viewing. While the color isn't quite as accurate in custom mode, it can look much more acceptable when the TV isn't the only source of light in the room.

The G25 has an option for displaying a 1080P/24 signal at either 48 Hz or the conventional 60 Hz. 48 Hz has some advantages in theory, but I couldn't get past the severe flicker I saw with it engaged.

I began by measuring the performance in various modes as they come from the factory. I noticed right away that standard mode had an unacceptable graininess to the image. Attachments 1-3 show the performance in custom, standard, and THX. Custom and standard show severe problems with gamma and other more typical problems. THX mode looked good, though it needs calibration for the white balance to avoid looking a little drab and off-white. THX mode put out a surprisingly strong 46 fL of light with a small 100% white window, which is much higher than I routinely get from THX modes in other displays. Also, the contrast was set to 60 in THX mode, meaning that there is a chance even higher light output could be possible.

As I began calibrating THX mode, I found that yes, it was possible to get gloriously bright images even in THX mode on the G25! This is the first THX certified plasma I have worked with to allow such flexibility, and it's a very nice treat. Taking the contrast up to 68 brought the light output up to 56 fL, which allowed me to match it's peak brightness to the S2 sitting beside it. It appeared to have room to go higher if desired with minimal to no consequences like white crush or gamma issues.

Having finished the THX mode calibration in the service menu, I moved on to custom mode. Now that THX is bright enough for a typical room, there is less need for separate day and night modes, but it would still be nice to have an alternative that is fairly accurate. Unfortunately, no matter what I tried in the service menu or the advanced user menu, I could not get custom mode's gamma to be acceptably accurate. That type of an inaccuracy will cause a clayface or caked on makeup look on brightly lit faces, and it will also reduce the sense of depth and naturalness. For the best, most accurate image on the G25, THX mode must be used.

Resolution was good with 1080P and 720P, but a little soft with 1080i. There was a slight shadow around some lines in the sharpness test pattern regardless of where the sharpness control was set. It looks like the opposite of edge enhancement. I have seen this on some other Panasonic plasmas, but not all.

ANSI contrast measured 1663:1, and black level measured .0083 fL with my Trichromat-1 colorimeter, which is more accurate and reliable at very low light levels than either the Chroma5 or i1Pro. The rest of the calibration was done with the i1Pro, since it is better with everything else besides the very dark readings.

Looking at some familiar Blu Ray material, the G25 produced a great picture! Flesh tones were very good, though possibly just a tiny bit redder than I normally see in THX modes. I'm splitting hairs with that call, though. Contrast was very rich with lots of pop, and shadow detail looked good even though the measurements suggested they were a bit emphasized. The picture had a sense of razor sharpness and good depth. I did get a slight impression of artificial enhancement that I normally do not get in THX mode, but I believe that it was just due to the fact that I had calibrated THX mode to a higher light output than is normally possible; and higher light output, in addition to raising contrast, can give the impression of added sharpness and detail.

Since a calibrated S2 was sitting right beside the G25, I was able to make comparisons between the two. Though I couldn't have them both on at the same time, I was able to switch from one to the other quickly. Room lighting was dark, and I used demo material from DVE and The Dark Knight Blu Rays. Both displays were calibrated to the same light output with a 100% white window.

With both sets turned off and the lights on, the S2's screen looked significantly milkier. The S2 picked up more visible reflection as a result. It was much harder to see my reflection in the G25 than in the S2.
Image quality was good on both, but had two very different perspectives. The S2's color was pleasing but less rich; the G25's colors looked more like how I know that material to look on reference grade displays.
The G25 looked more "contrasty", slightly richer, and slightly sharper. The S2, in comparison, looked very good but a little less exciting. There were a few occasions where I thought I detected some flashlighting or pumping in the G25, but not the S2. My overall impression was that the G25 is much more the Videophile's TV; it's accurate, and if that accuracy shows up flaws in the picture chain, that's the price you pay for having such a revealing display. On the other hand, the S2 is much more Everyman's TV; it's pleasant, looks very good, and never fails to impress your friends and family, but it's not quite being truly faithful to the image.

Overall I was quite impressed with the G25. The darker screen, higher light output in THX mode, very accurate colors, and good contrast and "pop" make it an outstanding plasma.

< =""> Attached Files

	Pan G25 before custom.pdf (156.7 KB, 191 views)
	Pan G25 before standard.pdf (160.2 KB, 81 views)
	Pan G25 before THX.pdf (147.8 KB, 138 views)
	Pan G25 after THX bright.pdf (144.2 KB, 233 views)

Så mellem en g20 og vt20.
mener forskellen er nogle forskelige indstiller som THX.