Sony KDL-46EX400 TV review: input lag and upscaling tested using the piLagTesterPRO

This 1080p TV from 2010 has a great picture but middle of the road input lag.

Overview/Image quality

At native resolution (1080p) this TV is pixel perfect: no aliasing, no cropping. This really should be the standard rather than the exception. The same is true of 480p/i, amazingly. It's almost true for 720p: no cropping, but a tiny bit of jagged edges visible on a 45 degree angle, as shown in the photo at right. This is very, very minimal by TV standards, however, and the result is that all resolutions look fantastic.

There are zoom/stretch options to crop more, and/or stretch 480p to fit the screen.

It has all the standard inputs, including 4 HDMI, VGA, and 2 yPbPr. I primarily tested on HDMI but I also hooked up a cheap yPbPr adapter and the results were identical except that 480i/p was noticeably blurrier. That could be the adapter. 

Input Lag

This display has a game "scene", which has two sub options: game-standard and game-original. But these actually work out to color/sharpening presets, they don't change the input lag.. It does offer noise reduction but not when in game mode. In fact, none of the image settings seem to change the lag or response time of the display at all.  

I used a piLagTesterPRO to measure input lag. This device sends a frame of video over HDMI and measures how long it takes to display it. Complicating things significantly, this TV is yet another display that does not actually sync to the input signal - instead it fills its own internal frame buffer from the video input and then draws that with a fixed additional delay of up to 16ms, randomly determined each time you turn on the set or switch inputs. At least it can actually draw at 60hz or 59.94hz so whatever lag you get when you turn on your console will be constant for that session, with no dropped frames. It can also draw at 24hz which is particularly nice for watching movies.

Because lag varies each time it is turned on, I've elected to report the average lag values here, since that seems fairest, but there's no right answer; for more discussion of this issue see the above link. 

Full Test Results 

I report two kinds of values. 1st response measures how long it takes for the TV to start responding (I use a 5% change in display brightness). This overly optimistic value doesn't tell how long it takes to see anything useful, but matches what other reviewers call input lag. full response is a more realistic measure of lag, and requires the display to reach 80% of full brightness. This combines both input lag and response time, and is closer to what you would actually experience in a game.

	top		bottom
Resolution	1st response	full response	1st response	full response	scan out	response time
480i	63.0	71.0	79.0	87.0	16.0	8.0
480p	28.0	36.0	44.0	52.0	16.0	8.0
720p	28.0	36.0	44.0	52.0	16.0	8.0
1080p	28.0	36.0	44.0	52.0	16.0	8.0

There's a lot of repeats here - every resolution is the same except 480i, which is 35ms (!!) slower because of deinterlacing (two full frames) 

I measured the responses time for black to white, but also various levels of gray to gray. The timing only varied by a +/- 1ms, which is very good. I've seen displays that are 2-3 times slower when measured using dark gray to light gray transitions (smaller transitions can be slower than full black to full white depending on the display tech).

Results compared to other displays

To allow quick comparison between many displays I've summarized the results across all the displays I've personally tested with the piLagTester Pro.  Min lag is the first response at the top of the screen, real lag is the full response at the bottom. 

Display	Year made	Native Res	native min lag	480i real lag	480p real lag	720p real lag	1080p real lag	native response time	native scan out
Vizio VO370M	2010	1080p	2.5	83.0	49.0	47.0	24.3	5.47	15.67
Dell E198FPb	2008	1024p	2.7		39.0	35.0		5.00	12.70
Samsung S27C230	2014	1080p	2.9		36.6	36.1	37.0	18.25	14.97
Dell U2410 (game)	2010	1080p	4.0	62.2	28.3	26.5	26.5	6.00	16.20
Panasonic TH-58PE75U	2008	720p	13.0	34.0	34.0	34.0	34.0	6.00	0.00
Dell U2410 (sRGB)	2010	1080p	20.5	62.4	45.0	43.1	43.1	6.13	16.13
Sony 40VL130 (game)	2008	1080p	22.8	66.3	49.0	47.3	47.3	9.08	15.43
Emprex HD 3202	2007	720p	27.0	126.0	51.0	50.0		8.50	15.00
Vizio VO22L FHDTV10A	2008	720p	28.0	94.0	61.0	61.0	61.0	18.00	15.00
Polaroid FLM-373B	2007	720p	28.0	82.0	49.0	49.0	49.0	7.00	14.00
GPX TDE3245W	2016	720p	28.0	102.0	51.0	51.0	51.0	8.00	15.00
Sony KDL-46EX400	2010	1080p	28.0	87.0	52.0	52.0	52.0	8.00	16.00
LG 42LC2D	2006	720p	28.3	54.6	50.8	50.4		6.30	15.95
Philips 42PFL3603D/F7	2009	1080p	29.0	84.0	50.0	50.0	50.0	5.00	16.00
Sony 40S20L1	2007	720p	48.4	90.1	72.9	73.4		9.60	14.00
LG 47LW6500-UA	2012	1080p	66.6	149.7	149.0	81.7	80.9	2.27	11.83

If it weren't for the variable lag this TV would be pretty decent, since recall that on a good day it can start to respond after only 20ms , mildly better than many TVs listed here. But the average lag is more representative, and once you add in the response time this TV is on the slow end of average at best.  The 480i results are some of the worst I've seen, too. 

Interestingly I'm starting to develop quite a cluster of results around 28ms min lag, and 50ms realistic lag. Interestingly, these are all sets that don't sync properly, too. Shared hardware from the late 2000s? LG, Sony, GPX, Polaroid and Philips sets all show this timing. They do differ on how 480i is handled, however, but perhaps that was handled by a 2nd chipset.

Conclusion

This would be a poor choice for lag-sensitive retro gaming. For JRPGs the deinterlacing quality is fantastic, however. And the lack of cropping and aliasing really makes this set worth considering despite the mediocre lag. Just watching TVs or movies, it's also very good. The fact that it can refresh the screen at 24hz makes it great for watching movies with a minimal amount of motion jitter. 

Other models 

I would expect that the 40EX400 and 32EX400 would perform about the same as the 46EX400, based on the model numbers, and a quick skim of the specs (all are native 1080p displays). But I only tested the 46EX400. The 46EX401/40EX401 are supposedly the same model but at Costco.