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mrwildeFlag for Australia

asked on

What is more important in a monitor refresh speed or input type

I am looking at a new 19" tft for the home to watch digital tv and movies and for comp work.

I have 2 I like but not sure what is the more important factor to consider.

19" Samsung 913N TFTMonitor, SILVER Color, 160 degree Viewing angle, Contrast Ratio 600:1, Brightness 300 cd/m2, Response Time: 8ms, Recommended resolution 1280x1024, 0.294 mm Pixel pitch, 16.2 Million colours, Analog, Height Adjustable, Pivot Stand, Thin Bezel, 15pin D-sub
or
19" Samsung 910T TFTMonitor, SILVER Color, Height Adjustable, Dual Narrow Bezel, 1280x1024 Max. Resolution, 170 degree viewing angle, Brightness 250 (cd/m²), Response Time 25ms, 1000:1 contrast ratio, Built-in Power, Pivot technology, 15Pin D-Sub Analog/DVI-D Digital Interface

Do i get the fast refresh unit that is analog or the digital unit witch has slow refresh.

It is one of those question that keeps me awake at night
Avatar of Watzman
Watzman


I'd keep looking for something faster with a DVI input.  If you have a DVI output on the source, I would not recommend an analog only input display, but at the same time you won't be happy with 25ms for games, and possibly not for TV or movies (although it does depend on the amount of "action" on the screen.  There are monitors that have a faster refresh and DVI inputs.  Note, however, that there is no standard for measuring response time, so one vendor's 25 might actually be faster than another vendor's 18.

Agreed with Watzman.... these guys (all LCD vendors it seems) use different standards to spec...

I have one of the newer Viewsonic ones

http://www.viewsonic.com/products/desktopdisplays/lcddisplays/proseries/vp191b/#specs

it was a bitch to find one on display to look at how it works with the real world (my old eyes)... but was worth the search.. check the specs tab out.

the other side of the coin is...... you should look at these things in a working environment b4 buying... and that is going to be a bear.. very few companies are going to carry a lot of them

There are ton of cheap LCD monitor deals these days.  I've seen them at www.tigerdirect.com, www.ecost.com, www.buy.com and www.amazon.com.  17" monitors as low as under $150, 19" as low as under $250.  Those are not name brands, and mostly don't have DVI or fast response times.  But I have seen name brands with DVI and quoted with 12ms and occasionally 8ms response times for $100 more ($250 for 17", $350 for $19").

Lots of deals, prices on LCD panels are falling very fast.

Avatar of Callandor
Both Samsungs are nice monitors (I have a 710N myself), but if movie watching is important, the contrast ratio of the 910T is a little better.  The 8ms response of the 913N is impressive, though, and if you are a gamer, that would be the choice.  I think the analog and digital inputs will be very close for these quality models and the size screen.  Is there a price difference?
Avatar of mrwilde

ASKER

$693 for the 913N-SL and $495 for the 910T2

i am more than happy to pay the extra if i get a better result. I know that it would be best to see them in action as one mans like is anothers dislike, but not eal easy.


I am thinking that becuase i want a media machine and wil be watching videos and tv the 8ms will be the better option.  
Since video is recorded at 30fps (and film is slower at 24fps), the 25ms should be ok if it is a true spec (33ms should be good enough, but allow for imperfections).  The higher contrast would be somewhat noticeable, though.
30 frames per second = 60 fields per second (each "frame" consists of an even field and an odd field), which corresponds to 16ms.  25ms is not really fast enough for blurr-free reproduction of NTSC TV video that has fast action elements; but it may be fine for more mundane material (Opra or Dr. Phil, for example).  How satisfactory it is or isn't depends in part on the material content.

I think I've seen prices for these and equivalent displays hundreds of dollars below those posted by the author.
That's true for a TV, which is an interlaced device, but all computer displays are progressive display devices, which show full frames.  Would a DVD recorded at 30fps display motion artifacts on a 60Hz progressive display?  (3:2 pulldown is a different issue)  I thought it wouldn't, but maybe I missed something.

With regard to TV, there is a "de-interlacing" process, but the consequence of that is that the refresh rate become 60Hz.  A DVD doesn't contain a TV signal, but rather a sequence of "stills" (could be thought of as a series of JPEGs, although it's not literally or technically correct), and I'm under the impression that on the DVD they exist at 60/second, and the DVD player (if it's a non-progressive STB DVD player) converts these to a TV signal.  Of course you are correct that if the source was a film motion picture, they are shot at 24fps, so every frame is displayed "twice" and every other frame is displayed "thrice" (at 60 Hz) to convert the 24fps film rate to 60Hz TV rate.  Regardless, I can tell you from experience that display of either TV or computer games with a lot of fast action on a "25ms" LCD monitor will result in smearing or ghosting that many if not most people will find objectionable.  It's simply not fast enough for fast action scenes.  It's somewhat like watching TV on an old (very, very old) CRT with a "P7" (radar) phosphor, but not nearly so extreme.

I found this site which explains a little more detail about what happens with frames in the DVD display process: http://www.mplayerhq.hu/DOCS/HTML/en/menc-feat-telecine.html  It seems the difference between TV displays and computer monitors is the way video is shown, field after field versus frame after frame.
If you are getting any type of LCD monitor... refresh speed is not important... keep it set to 60Hz... there will never be flicker or the need to reduce flicker on an LCD tft monitor.
Now, the type of input to prefer is DVI... and most higher end LCD monitors have the DVI input and lots of newer video cards come with a DVI output.... it shouldn't be a problem to implement :-)  So, Input type is important, refresh rate is not important.

Jeff
at yourtechonline.com
J-A-L,

I think we were talking about "response time", not "refresh speed"  ;-)
The response time is the refresh speed...  1/responsetime = refresh rate.
Personally... I wouldn't buy an LCD monitor without seeing it in action first. (ok, I bought a Dell 2005Wide Screen 20" on faith..hahaha) but i accepted it anyways.  COntrast ratio is more important than all of them and will give you joy.  If you have poor contrast, everything will look pretty sucky.  I would take the DVI 1000:1 contrast monitor probably.  The 25ms second response time sounds like white to black transition rather from grey-to-grey possibly... those figures can be misleading and you should look up the full technical specs on samsungs website.

Picture quality is the most important so if you can see then side by side that'd be a big help in determining which is your favorite :-)

Jeff
at yourtechonline.com

Response time and refresh rate are not the same thing.

Refresh rate is the number of times per second that each pixel on the screen is written ... typically 60 Hz or 70 or 72 Hz (60, 70 or 72 times per second).

However, the problem with LCD displays is that the pixels do not respond instantly either to being turned "on" or to being turned "off".  This is "response time", and sometimes it's even given as two separate numbers for the "on" time and the "off" time.  For example, in a particular display, from the time that a pixel is turned "on" it may take 15msec to reach some specified percentage of maximum brightness (typically, anywhere from 50% to 100% is used), and then when it is turned "off" it may take 10 msec for the brightness of that pixel to drop to some specified percentage of it's full-brightness "on" value, OR to extinguishe to within some specified percentage of it's specified "full darkeness" off value.  Usually (but not always) these are added together to give an overall "response time".

However, there is no industry standard for the measurement of an LCD panel's response time, so, as noted, on manufacturer's "25 msec" panel may actually be faster than another vendor's "18 msec" panel.

And, in any case, the response time (which, by the way, also varies with the panel fluid temperature) has nothing to do with the video signal refresh rate.

While response times down to 8 msec are currently being promoted, the most common response time is 25 msec, which only nominally supports a 40Hz refresh rate.  However, for almost all manufacturers, this is only a measurement of the time required to rise to or fall from a lot less than "full on" or "full off" (often, 50% brightness is used for the measuring points).  In such a case, the true response time, the time to go from nearly totally off to nearly totally on and back, for a panel with a nominal response time of 25 msec, may in fact be a lot more than 25 msec.

You said it yourself "the most common response time is 25 msec, which only nominally supports a 40Hz refresh rate".  1/.025 = 40hz if you know one, you'll most likely know the maximum of the other... and even then you still have to check the specs because 8ms is typically an average grey-to-grey transition, not black to white.  I said 1/responsetime= refreshrate and you just said the same thing... if you read the whole thing.

Either way... I would say an appreciable increase in contrast would definately be better anyways since it would bring out more details and screen objects won't be as potentially washed out.

Jeff
No, I didn't say the same thing.  The refresh rate refers to an electrical characteristic of the signal coming out of the video connector, either the VGA connector or the DVI connector.  If it's the VGA connector, it doesn't even know if it's going into a CRT monitor or an LCD monitor.  But you can still change the refresh rate from any of the supported (or sometimes custom) values.  None of this has anything to do with "response time", which is entirely a function of the liquid crystal material inside the actual LCD panel.  And you can drive any panel -- with a fast or slow response time -- with any signal (with a fast or slow refresh rate).  You may not like what you see, but you can do it.  And refresh rate and response time, while both playing a major factor in the quality of what you see, are still two very different and unrelated parameters.
Hi ya' Watz... well, I don't really care about yer video card refresh rate ;)
but the refresh speed (of the monitor), and response speed (of the monitor)are related.  Do you normally set your refresh rate to something the monitor can't support because it's response time is too slow?  No, right?  We are talking about what gives the best picture..right?  I didn't think you were talking about Video card refresh rate.. that's not important... of course you set it to what is supported by the monitor.

The refresh rate is ALSO the electrical characteristic of the VGA signal, but is it ALSO the rate at which the monitor will optimally redraw the screen... despite what the VGA card can do.

The response time is the amount of time an organic LCD takes on average to molecularily change the LC orientations to let thru or block certain light characteristics... and they are related... if your response time is slow, your SUPPORTED refresh rate will be slow too BECAUSE the panel can only "successfully" refresh your panel as fast as the individual pixels can respond.

You'll have to explain to me how refresh rate (for a monitor) and response time (for a monitor) have nothing to do with each other. ;-)

Jeff
Avatar of mrwilde

ASKER

OK I am stepping in here before this gets all bloody and people get violent.  

refresh is a CRT term (for example) and response is the tft equivelent and from understanding of the universe and all things big and beautiful, if we are discussing montiors( and we are ), they become the same but they are not.
Agree to disagree perhaps, i would say for arguments sake Jeff is correct.

This of course is not directly anwsering my question, but thankyou for the entertainment it is enjoyable.

I am also leaning towards the unit that is dvi with a better contrast ratio. But if there any further arguments to add please do so and i will award points in the next day or so.  J-A-L is ahead at the moment

MR Wilde
Avatar of mrwilde

ASKER

The other thing to keep in mind is that i would by the monitor then the card to suit not the other way round
ASKER CERTIFIED SOLUTION
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J-A-L

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J-A-L thanks for all your advice and information I did learn agreat deal from this posting.  Thanks to every else who also posted