Sharp LC-C3234U TV review: input lag and upscaling tested using the piLagTesterPRO

This 720p TV from 2009 retailed for around $800. It is good at upscaling 480i/p but has average to below average input lag. 

Overview/Image quality

Unfortunately I didn't have a remote for this TV and you can't change the scale or aspect ratios without it, so I can only judge scaling with the factory defaults, which are to stretch 4:3 to 16:9. Although this is disappointing, the defaults do good job otherwise: there's no aliasing in either 480i/p or 720p. There is cropping, about 20 pixels off all edges in all modes. 480p/i is mildly soft but you can still see individual pixels, and 720p is a good bit sharper. I suspect the native resolution is 1366x768, which is a mode the display supports, but still insists on cropping, though it still looks very sharp and has no aliasing. I guess the name "Sharp" means something, in this case ;-)

In addition to 60hz the display will also take 75hz signals for some resolutions - but it just draws them at 60hz with lots of dropped frames. It doesn't go any lower than 60hz, unfortunately, so no 24p for watching movies. 

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

Input Lag and video sync issues

This display does not have a game mode; not even a game 'color' preset. There is a game timer, which apparently keeps track of how long you've been playing games. "Cute".

What other video settings the TV has made no difference on the input lag. 

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. 

Because of the lack of proper sync each time you switch to a new input you'll get a different amount of input lag. To take one example, input lag for 720p will vary from 25ms to 42ms. 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.

At least it can keep up with 60hz and 59.94hz signals correctly, so  there's no dropped frames, and input lag is constant for each gaming session.

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.

Resolution1st responsefull response1st responsefull response

This set is fastest at its native resolution of 720p, where it takes an average of 33ms to start drawing the input. Downscaling to 480p might add a couple of milliseconds, though it's hard to be sure since the TV has such variable lag. Deinterlacing (aka 480i) adds another 16ms of lag, which actually decent - some deinterlacers take a full 32ms. 

I measured the responses time for black to white, but also various levels of gray to gray. The timing varied from 12 to 20ms, with bigger brightness changes taking longer. 15ms was the typical value, which is what I'm using for the "full response" listed above. 

Results compared to other displays

To allow quick comparison 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 (meaning at 60hz a display will have at least 16ms of lag).

This list is sorted by 720p real lag since all displays support that resolution. 

DisplayYear made (TV?)Native Resnative min lag480i real lag480p real lag720p real lag1080p real lagnative response timenative scan out
Dell U2410 (game)20101080p4.062.228.326.526.56.0016.20
Panasonic TH-58PE75U2008720p28.
Corprit D157 (hdmi)20211080p3.134.934.834.633.916.2515.13
Dell E198FPb20081024p2.739.035.05.0012.70
Samsung S27C23020141080p2.936.636.137.018.2514.97
Vizio E470VL (vga)20111080p22.
Dell U2410 (sRGB)20101080p20.562.445.
RCA L40FHD4120101080p20.365.
Vizio VO370M20101080p2.583.
Sony 40VL130 (game)20081080p22.866.349.047.347.39.0815.43
Polaroid FLM-373B2007720p28.
Philips 42PFL3603D/F720091080p29.
Emprex HD 32022007720p27.0126.
LG 42LC2D2006720p28.354.650.850.46.3015.95
GPX TDE3245W2016720p28.0102.
Sony KDL-46EX40020101080p28.
Vizio VO22L FHDTV10A2008720p28.
Sharp LC-C3234U2009720p33.083.666.664.615.0016.60
Sony 40S20L12007720p48.490.172.973.49.6014.00
Samsung HP-T425420111080p69.794.
LG 47LW6500-UA20121080p66.6149.7149.081.780.92.2711.83
Vizio E470VL (hdmi)20111080p69.0128.

This TV is definitely below average. there's a large clump in the middle where the input lag is around 40-50ms but this set is a good 14ms slower than that. So it's definitely not for action games. It does an excellent job of upscaling so for non-action retro gaming it might be reasonable.  And it's 480i performance is at least average, due to only taking 16ms to deinterlace. 


This would be a poor choice for action gaming.  Just watching TVs or movies, it's fine, however. If you care about aspect ratios be sure to get the remote too.

Other models

I tested the Sharp LC-C3234U model. They also made a LC-32D44U, which should be the same, based on identical part numbers in their service manual, but I haven't checked any other sources to be sure. 


Anonymous said…
Its too bad that you didn't test this TV in game mode. The Sharp actually has a game mode, but its not where you would expect to find it in the menu options. Its one of the AV Mode options, along with Standard, Movie, PC, User, & Dynamic.

Its too bad that I didn't catch your findings sooner, as I'd have been curious to see the results in game mode.
Alan Robinson said…
Are you sure this exact model has it? I didn't have the remote so some options were inaccessible so I definitely could have missed it.
Anonymous said…
Sorry for not checking back sooner. Thanks for responding.

Yes I own this exact Costco-only model. I'm considering replacing it, because mine has become flaky about not powering up and flashing an error code frequently. Probably a PSU or board issue. A few years after I bought it, it started powering itself on sometimes in the middle of the night. That stopped after a while but it was probably symptomatic of some hardware issues that have turned into its current behavior.

Its unfortunate you don't have the remote. You can sort of work your way through the menus using the set-top buttons. However, it seems the only way to switch between the 7 available AV modes is using the AV mode button on the remote.

I just dug up the users manual, and the description of Game mode states "Lowers image brightness for easier viewing." And further down on the page it says "When you play games, 'GAME' is recommended for AV mode". So either they were being vague, or game mode does nothing to reduce input lag. I always felt like games were more responsive in that mode compared to the other AV modes, but maybe I was just fooling myself. If Game mode does nothing significant, I guess almost any modern TV will be a big upgrade for video gaming.

Email me


Email *

Message *

Popular posts from this blog

Panasonic TH-42PX75U Plasma TV review: input lag and upscaling tested using the piLagTesterPRO

piLagTester PRO order page

A $5 TV Input Lag tester using a Raspberry Pi Zero