Polaroid FLM-373B review: input lag and upscaling tested using the piLagTesterPRO

This 720p TV from 2007 is rather mediocre, with variable input lag, aliasing, and in general very little to recommend it for gaming, retro or otherwise. Edward Land should be tossing in his grave that the once-innovative Polaroid name gets attached to junk like this.

Overview/Image quality

At native resolution (720p) this TV doesn't look that great - it crops 40 pixels off the left and right side of the screen (and also about 20 off the top and bottom). Who knows what the actual resolution of the screen is, as after throwing away that many pixels the screen still has bad aliasing (see photo of 1x1 pixel checkerboards at right). 

Surprisingly, if you give it 1080p/i it actually looks smoother than 720p, with less jaggies, though of course any fine detail is blurred away, since the panel resolution is fairly close to 720p (probably it's 1366x768). 

In a disappointing first, this tv doesn't offer any control of how a 4:3 video signal is displayed: it's stretched to fit the screen no matter what. Apparently it can be adjusted using a button on the remote (which I don't have) but there's no option in the on-screen menus. 

It has all the standard inputs, including 1 HDMI, VGA, and 2 yPbPr. All test results were identical for HDMI and YPbPr. 

Input Lag

This display does not have a game mode; not even a game 'color' preset. In fact there are zero display quality settings to toggle, just the standard brightness/contrast/color, etc. adjustments. 

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 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 that is randomly determined each time you turn on the set or switch inputs. The maximum draw rate is 59.94hz, so 60hz (or the "supported" 75hz) just drops frames in order to keep up. At least there's no drift in the input lag for 59.94hz signals. Of zero relevance to gamers but still notable, it can draw the display at 50hz when given a 50hz signal (no doubled frames). So it might be good for watching movies.

Because of the lack of proper sync each time you turn on a new input you'll get a different amount of input lag. To take one example, input lag for 720p will vary from 20ms to 36ms. What you get seems to be entirely up to chance. 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	61.0	68.0	75.0	82.0	14.0	7.0
480p	28.0	35.0	42.0	49.0	14.0	7.0
720p	28.0	35.0	42.0	49.0	14.0	7.0
1080p	28.0	35.0	42.0	49.0	14.0	7.0

 

There's a lot of repeats here - every resolution is the same except 480i, which is 33ms slower (suspiciously, that's exactly the length of two frames of video).  

Interestingly, even upscaling to 1080p doesn't slow the panel down relative to its "native" resolution. 

The scan out appears to be slightly faster than the refresh rate, suggesting that once the panel starts drawing it actually goes from top to bottom slightly faster than the data was transmitted. 

I measured the responses time for black to white, but also various levels of gray to gray. The timing only varied by a +/- 2ms, which is good. I've seen displays that are 2-3 times slower when measured using dark gray to light gray transitions. 

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. 

		computed (ms)
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
Dell U2410 (game)	2010	1080p	4.0	62.2	28.3	26.5	26.5	6.00	16.20
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
Sony 40S20L1	2007	720p	48.4	90.1	72.9	73.4		9.60	14.00
Emprex HD 3202	2007	720p	27.0	126.0	51.0	50.0		8.50	15.00
LG 42LC2D	2006	720p	28.3	54.6	50.8	50.4		6.30	15.95
Vizio VO370M	2010	1080p	2.5	83.0	49.0	47.0	24.3	5.47	15.67
Philips 42PFL3603D/F7	2009	1080p	29.0	84.0	50.0	50.0	50.0	5.00	16.00
Samsung S27C230	2014	1080p	2.9		36.6	36.1	37.0	18.25	14.97
LG 47LW6500-UA	2012	1080p	66.6	149.7	149.0	81.7	80.9	2.27	11.83
Vizio VO22L FHDTV10A	2008	720p	28.0	94.0	61.0	61.0	61.0	18.00	15.00
Dell E198FPb	2008	1024p	2.7		39.0	35.0		5.00	12.70
Polaroid FLM-373B	2007	720p	28.0	82.0	49.0	49.0	49.0	7.00	14.00

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 , 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 particularly bad, too. 

Conclusion

This would be a poor choice for gaming of any type, particularly retro gaming.  Just watching TVs or movies, it's fine, however. 

Other models (to avoid)

I tested the FLM-373B model, which is the 37" version. They also made a FLM-323B and FLM-263B.  Based similarities in their names, I suspect they would perform similarly just with smaller pixels. The manual also mentions the FLM-2632, FLM-3232 and FLM-3732, showing then with the exact same specs, including weight and dimensions, so I suspect this was sold with custom model numbers for different stores (so that for instance, Best Buy didn't have to price match with Walmart, or something).  However, I've made no efforts to check, so that's only a quick guess.