Originally Posted by Chad B
Several years ago, Samsung’s first Full Array Local Dimming LED LCD, the UN55B8500, offered video enthusiasts the incredible contrast we craved; and we eagerly awaited larger and newer models with similar FALD technology. However, it turned out to be a painfully long wait, as Samsung released only edge lit LEDs as replacements. Thankfully, their new UN65JS9500 finally fills the void for those of us who desire better contrast than edge lit technology allows. The JS9500 also features Quantum Dot LED technology and 4K UHD resolution, and it supports High Dynamic Range HDR playback.
The JS9500’s backlight is divided up into individual areas, with each zone illuminating only when picture content is being reproduced in it’s own part of the screen. The effectiveness of this technology is dependant on the number of zones, more being better; the intelligence and action of the dimming-boosting; the shape and definition of the zones; and the native panel contrast.
The number of zones plays a very important role, because fewer zones means more screen area around the picture content will glow, causing annoying blooming. Early FALD sets had anywhere from 90 to well over 200 zones, though sadly it seems that the trend has been going down in the few FALD offerings from Vizio and others. I counted 150 zones in the 65JS9500, with 10 rows of 15 across.
The JS9500 seemed pretty smart when it came to dimming action; stationary objects illuminated the zones less than moving objects, and moving objects gracefully illuminated the incoming zone while dimming the outbound zone in a similarly smooth fashion. However, some measurable white balance and gamma shifts occurred in the process, meaning that contrast aside, pictures will have some subtle but real dynamic shifts as the dimming action ramps up and down in different areas of the picture.
The shape of the 65JS9500’s zones is very diffuse. The most extreme example of sharply defined zones I’ve ever seen was in LG’s 55LE8500, where zones lit up like distracting squares and greatly diminished picture quality. Most FALD sets have moderately diffuse zones, giving a somewhat soft, diminishing glow around picture objects. I measured the glow area of the 65JS9500 at around 10-12” square for objects near the center of the screen, which will lead to the blooming being very gradual but covering a wide area of the screen.
The 65JS9500’s native panel contrast depended somewhat on the calibration technique used, but I found that the maximum attainable figure for Movie and the Cal Day and Night modes was a moderate 1843:1 (45/.024 fL). For comparison, the native CR of FALD sets from LG measure around 800-900:1, while the Sony X950B measures 3882:1 and the latest Vizios go even higher. All else being equal, this means that the visibility of the blooming on the JS9500 will be somewhat middle of the road.
The JS9500’s curved screen is very dark and soaks up ambient light like a sponge, though it’s shiny gloss means reflections can be very defined in some situations. I found it’s off axis behavior to be fairly sensitive to viewing angle, so viewers sitting more than a couple feet off axis at typical distances will see some shifts in picture quality from one edge of the screen to the other. The curved screen helps picture quality for viewers who are seated dead center and at closer than normal distances, because the screen edges will be more on axis in that situation.
I began my evaluation of the JS9500’s various untouched picture modes in a room with moderate ambient light, watching some familiar Blu Ray 1080P/24 material.
Standard mode offered superb contrast, though shadow detail was too dark, making dark objects sink into black. The Soap Opera Effect, that hard to describe sensation of movies looking too much like video, was present, as well as some Dirty Screen Effect, which can give the illusion of greasy thumbprints in panning large white objects like clouds or hockey rinks. Orange tones looked too red, and reds were oversaturated, though skin tones were fairly well controlled. Colors appeared strong though cool and clinical. Detail was etched and hard, and bright white levels appeared slightly blended together. There was a surprising amount of depth, images popping off the screen in a very cool manner. Overall, the image looked impressive but overly enhanced and not very natural.
Natural mode had even more pop, but with reddish skin and orange tones. Natural looked quite similar to Standard but brighter and slightly more colored.
Movie displayed much more natural colors; red, orange, and blue shades looked real. However, it was still plagued by the pesky Effects gang, with SOE and DSE detracting from the picture quality. Somewhat earthy toned, Movie had a slightly off-white look in place of the cool and clinical color tones of Standard and Natural. Skin tones were just slightly too ruddy. Shadow detail was good and strong, though I felt it had a somewhat reddish cast at times. The picture had good depth and excellent contrast. Textures of moving objects appeared slightly smoothed, as would be expected with aggressive noise reduction.
Some quick fixes to improve Movie mode short of a full calibration would be to go to the picture options, turn the Digital Clean View to off or low, turn MPEG Noise Filter off, turn Auto Motion Plus off, and experiment with changing Warm2 to Warm1. The DCV set to low did seem to reduce graininess without glaring consequences, though purists would want to turn it off. Optimal AMP settings seemed to depend on the source material; 1080P/24 Blu Ray looked great with Custom settings of Blur Reduction 10 and Judder Reduction 1 (0-2 OK), though later when I viewed cable content the most natural motion by far was with AMP turned off. I turned AMP off for mixed Blu Ray and cable TV content. Neither Warm2 nor Warm1 will likely be perfect before calibration. Warm2 will be measurably closer, though it still may look worse than Warm1, which errs in a more palatable direction.
Although the technically correct sharpness setting is around 0, I found that a setting of 10-20 eliminated a slightly soft look to cable content without causing much edge enhancement.
Movie mode’s default contrast setting of 90 causes the 10 point white balance control to be progressively displaced, with lower intervals matching but higher intervals not adjusting the brightness range specified. For example, with contrast at 90, interval 80% of the white balance actually adjusts 87%. The contrast must be at 100 for no displacement. However, setting contrast at 100 causes full brightness colors to be reproduced at a lower luminance than darker colors. Reducing the contrast to 85 eliminated the color gamut luminance issue, though it caused 10 point displacement and reduced contrast ratio. Contrast calibration can therefore be a bit of a balancing act.
I found another balancing act in the setting of the global color control. Normally, that control would just be left at default, and the CMS adjustment would be used to calibrate the hue, saturation, and luminance of the primary and secondary colors. Surprisingly, I found that starting the CMS adjustment with a lower global color setting reduced the gamut luminance dropoff noted above, though it would then cause a discontinuity between full purity colors and paler colors, making color shadings and skin tones too pale despite measurements indicating they should be fine.
Further complicating the calibration were the gamma and white balance shifts caused by the local dimming. It was quite challenging to get the measurements to agree with the overall look of the picture. When I initially did the calibration with the dimming turned off, the match was not what I hoped for. With the dimming on, different results will be obtained depending on the type of measurement windows or fields used. Smart LED high measured differently than low or standard, with high degrading the gamma more. APL windows seemed to give the best match, though real time adjustment of the 10 point control was then thrown off by having the menu screen displayed on the screen. The best method is likely to use windows around 10% in size with a 22-25% APL surround, and not to try to do the 10 point adjustment in real time but rather do a lot of hopping in and out of the menu. Because of these calibration challenges, the JS9500 ended up taking much more time to dial in than usual.
Samsung has for years made available to calibrators two additional picture modes called CAL-DAY and CAL-NIGHT, which could be activated in the service menu. However, up until the JS9500, these modes have been plagued with bugs, such as carrying over the 10 point adjustments from day mode to night mode and vice versa, not applying all the advanced settings to the Smart Hub even when instructed to do so, etc. Happily, these issues have been remedied in the JS9500, and the modes can be used as true day and night calibration modes.
I looked in the service menu for any controls that might be helpful in remedying any of the calibration challenges such as dynamic color settings or similar, but found nothing of interest in the service menu beyond activation of the day and night modes.
With a 1080i input and custom AMP settings, my Jeti spectroradiometer synced to the screen output at 119.8 Hz.
Maximum light output, with backlight at the highest setting and Smart LED at standard, was 77.9 fL with contrast at 90 and in the 80-90 fL range with contrast at 100. Although I did not write it down in my notes, I also measured maximum light output with Smart LED on high and I believe the result was not much higher, the high setting dramatically boosting brightness at low backlight settings but not much if any at high backlight settings.
Using custom APL “torture test” windows (50% size, 99% APL), I measured the following worst case scenario contrast ratios:
Smart LED off: 1843:1 (45/.024 fL); Smart LED low and standard: 3935:1 (45.2/.011 fL) Smart LED high: 3940:1 (77/.0195 fL). Turning Smart LED to high was like turning on a brightness turbocharger, though it did not increase the contrast ratio.
Using 10% size 25% APL windows, which will approximate real content, gave the following results:
Smart LED low and standard: 15456:1 (43.1/.0028fL); Smart LED high: 16058:1 (73.6/.0046 fL).
Using full fields or conventional windows, the contrast ratio was immeasurable since the dimming made the blacks perfectly black.
Screen uniformity was evaluated with full fields at black, dark (10-25% brightness), and mid-bright (50-100% brightness) picture levels.
With Smart LED off, black uniformity was poor, with obvious clouding in several areas. With dark content, it was fair on the right side with a bright area extending several inches from the edge and a slightly darker area right in from that before it became good in the center. It was then fairly good on left side, with a less noticeable bright area at the edge. With mid to bright content, it was fairly good, with just barely noticeable color shifts of green and pink across the screen, and a minor small dark area in the middle right edge.
With Smart LED on standard, the uniformity was the same as above with mid to bright content. Dark uniformity was good, with just minor problems along the right side.
Unfortunately, I did not get to view Ultra HD or HDR content on the JS9500 at this time, but I will edit this post when that opportunity occurs.
With the calibration finally done, viewing HD content in a dark room, the JS9500 had excellent pop and depth, far beyond what can be achieved with edge lit LEDs. Video motion was very good. Some blooming was visible in very dark scenes and credits, however.
I had to wonder, is the Quantum Dot technology really a big deal with normal HD content? Probably not, though there were some color characteristics that were different than previous Samsung LEDs in minor ways.
Regardless, skin tones looked very good; they were rich and realistic without making everybody look like they had chronic sunburns. In fact, that richness and realism extended to all colors.
The JS9500 displays a beautiful picture with HD content, though there are other displays that can make the same claim. While I liked the image a lot, I am not about to crown it the best display of all time; at least not until I get to evaluate it with some quality UHD and HDR content. For now, I’ll say the JS9500 is good enough to make me very eager to push it to it’s limits when appropriate content becomes available.
So if I understand you well, when using the local dimming either on low or on standard, the contrast ratio is not as bad as expected. Is that it? It even seems quite impressive.