Results: Grayscale Tracking And Gamma Response
Our grayscale and gamma tests are described in detail here.
The 34UC97 comes with a factory-certified calibration in the form of a test result data sheet. LG measures grayscale tracking and gamma for each sample as it comes off the manufacturing line. Our out-of-box results, while decent, are not quite as good as claimed. The likely reason is that LG uses DeltaE 94 to track errors and we use DeltaE 2000, which is more stringent. Our analysis definitely falls in the realm of nit-picking, however. Aside from tiny aberrations in the 50- to 90-percent levels, this is good tracking.
After calibration, we achieved a superb result with no issues at all. The 34UC97 is obviously capable of professional-level accuracy. Given that it costs as much or more than many pro models, that’s a good thing.
Here is our comparison group:
A result of 2.57 DeltaE is perfectly respectable for any business-class screen. If you just want to plug and play with the 34UC97, you will be very satisfied with its image quality.
Of course, .72dE is even better. It's a worthwhile improvement to the monitor's grayscale tracking. We’re glad to see that the two most expensive displays include factory calibrations and can live up to their billing.
Even though the 34UC97 ships in a factory-calibrated state, there is one important thing you must do if you want proper gamma tracking: turn off the Smart Energy Saving feature. If you leave it on, you’ll see a little brightness pumping in the image as content changes from dark to light. In our tests, each pattern flickered a bit as brightness increased. It’s a little like the auto-iris on a projector, except it does nothing to improve black levels.
We left the gamma preset alone and turned off SES. The resulting trace isn’t as flat as we’d like, but it’s not too bad. The impact on picture quality is barely noticeable. In the mid-tones you might see a slight flattening of the image. Most users won't perceive a problem, though.
Here is our comparison group again:
The slightly wavy tracking results in a last-place finish. Gamma values range from 2.37 to 1.94. It’s not that bad, but the other displays fare better.
We calculate gamma deviation by expressing the difference from 2.2 as a percentage.
The average value is 2.10, which is 4.54 percent below our standard of 2.2. We tried using the next-darker gamma preset, but this resulted in white balance issues at the higher levels. This is the only area where the 34UC97 could use some improvement. Color, as you’ll see on the next page, is quite good, as are the contrast and grayscale results we’ve recorded so far.